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FORMERLY: ADVENTURE IN A BACKPACK

How to Design and Install Solar on a Camper Van

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THE ULTIMATE DIY CAMPER VAN SOLAR GUIDE

Welcome to the ultimate DIY Camper Van Solar guide by EXPLORIST.life.  This guide will take you not only our solar builds, but more importantly, the details of how YOU can build your own solar setup on your camper van, truck camper, RV, or Camper.  There is a LOT of information in this blog post and it's constantly evolving.  If All you are looking for is parts lists and wiring diagrams, you are in luck.  We have COMPLETE solar wiring diagrams at the bottom of this blog post.  If you want to know the WHY… bookmark this page, grab a coffee (or two) and get comfy.  We're going to break it down for you.

ATTENTION

Electricity is DANGEROUS!

It's important to note that I am NOT a licensed electrician. My advice does NOT supersede what you find in your OFFICIAL owners manuals from any of the products I recommend.

‘Read the Manuals of the Equipment I recommend'

I do make my best effort to deliver accurate information based on data driven statistics and best practices, but you MUST use your own best judgement when taking on an inherently dangerous DIY project.

Proceed at your own risk

WHAT ARE THE MAIN PARTS OF A SOLAR SYSTEM?

DIY SOLAR SYSTEM COMPONENTS

This section of the blog post will cover all of the main individual components that you will need in your DIY camper van solar install.  In this section, we will focus on the broad catagory of each component, but I will give a few recommendations on individual brands and parts.

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SOLAR PANELS

MAIN PARTS OF A SOLAR SYSTEM – SEC. 1

Basic Function

The solar panel gathers solar energy from the sun and passes that to the next step of the system; the solar controller.

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CHARGE CONTROLLER

MAIN PARTS OF A SOLAR SYSTEM – SEC. 2

Basic Function

The Charge Controller takes the power made by the solar panels and transform the ‘solar panel power’ into a form of power that the batteries can use.

How does the Charge Controller Work?

Solar panels typically put out a voltage that is too high for batteries to use. If you have your solar panels wired in series like I recommend, you could possibly have over 100 volts coming out of the solar panels. If you connected your 100 volts from the solar panels directly to the battery, it’s not going to work. The Charge Controller regulates the voltage from the solar panels back down to the 12.6 – 14.6 volts that the batteries can store/use.

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MPPT vs PWM CHARGE CONTROLLERS

There are two main types of charge controllers. They are MPPT and PWM. This blog post is a crash course in solar design and getting into the specifics of the differences is out of the scope of this blog post. Here’s what you need to know regarding MPPT vs PWM charge controllers MPPT is the newer, more efficient technology. From here on out, any time I talk about charge controllers, I will only be talking about MPPT charge controllers as I want to guide you to build a high-end, expandable solar setup.

HOW TO MATCH SOLAR PANELS TO A CHARGE CONTROLLER

One of my favorite series of charge controllers is the Victron BlueSolar MPPT Charge Controller. If you’ll notice, there are MANY different sizes of charge controllers:

  • Victron SmartSolar MPPT 75 | 10
  • Victron SmartSolar MPPT 75 | 15
  • Victron SmartSolar MPPT 100 | 15
  • Victron SmartSolar MPPT 100 | 20
  • Victron SmartSolar MPPT 100 | 30
  • Victron SmartSolar MPPT 100 | 50
  • Victron SmartSolar MPPT 150 | 35
  • Victron SmartSolar MPPT 150 | 45
  • Victron SmartSolar MPPT 150 | 60
  • Victron SmartSolar MPPT 150 | 70
  • Victron SmartSolar MPPT 150 | 85
  • Victron SmartSolar MPPT 150 | 100
  • Victron SmartSolar MPPT 250 | 85
  • Victron SmartSolar MPPT 250 | 100

WHAT DO THOSE NUMBERS MEAN?!?

Lets use the Victron SmartSolar MPPT 100 | 30 for example. The 1st number, 100 means the maximum input voltage the controller can handle. In other words, the Victron SmartSolar MPPT 100 | 30 can handle a max of 100 volts coming from the charge controller. The 2nd number, 30, represents the max amount of amps the controller can output going INTO THE BATTERIES.

*MATH ALERT*

Let’s say, for example, you have 4 x 100 watt solar panels with the following stats.

EACH panel has an ‘Optimum Operating Voltage’ of 18.9 volts and a Optimum Operating Current of 5.29 Amps. Those are the two numbers we are concerned about for now. I generally recommend just wiring all of your solar panels in series for simplicity and efficiency sake. Which means… Those 4 x 100 watt solar panels get wired together like this:

Since they are wired in series, the voltages get ADDED together for a total of 75.6 volts. (Optimum Operating Voltage of 18.9 x 4 panels) The amps on the “upstream” side of the solar panels remains 5.29. So, the 75.6 volts is under the safe threshold of the 100 max volts of the Victron SmartSolar MPPT 100 | 30 solar controller. That’s the first number. What about the 2nd number, 30? That is the MAX resulting amps AFTER the solar controller has worked it’s magic. We need to do some math to determine the amperage. Here are the things we know:

  • We have 4x100 watts of solar panels totaling 400 watts of solar.
  • During ‘Pedal to the Metal’ charging, batteries charge at ~14.4 volts
  • Amps = Watts / Volts

400 watts / 14.4 volts = 27.7 amps

This means, the amps for this particular setup are RIGHT on par with the max this particular solar controller can handle.

RENOGY CHARGE CONTROLLERS

The ever popular renogy solar controllers are also a good choice. Renogy has 2 models of MPPT controllers, the Rover and the Commander. Their naming structure isn’t as straightforward as the Victron solar controllers, but I’m here to help.

  • Renogy Rover 20 – 20 | 100
  • Renogy Rover 30 – 30 | 100
  • Renogy Rover 40 – 40 | 100
  • Renogy Commander 60 – 60 | 150

This was a pretty in depth section. If you still have questions, head to the comments section below and I’ll see if I can clear things up. *NOTE – Everything above is for a 12v battery bank. A 24v battery bank with be slightly different, but for the sake of making this less confusing, it’s omitted from this section of the blog post.*

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BATTERIES

MAIN PARTS OF A SOLAR SYSTEM – SEC. 3

BASIC FUNCTION

The batteries are basically the ‘storage tanks’ of your solar setup.

Types of Batteries

There are 3 main types of batteries on the market.  Lead-Acid, AGM, and Lithium.  Here is a quick overview of those 3 different types of batteries typically used in solar setups.

Lead Acid

Lead-acid batteries are the batteries found in most cars as their starting batteries. They are your standard, run of the mill automotive battery. They require regular maintenance and need to be vented as they produce hydrogen gas which can corrode metal in the surrounding area. For our purposes, in my opinion, they are not worth the hassle and this is the last time we will mention lead-acid batteries in this post.

AGM

AGM batteries do not offgas nor do they need regular maintenance, Cool!  They are perfectly fine for a mobile battery bank and will indeed work if you are having to pinch pennies, but they are already outdated. We will talk about why in the AGM vs Lithium Comparison.

Lithium

Lithium Batteries are the current cream of the crop. They are the newest technology with the highest performance as well as lightest weight (and weight IS important in a mobile solar build). They do not need to be vented and they do not offgas.

FREQUENTLY ASKED QUESTION

Q: What about the Tesla Powerwall or Tesla Modules?

Nates Answer:

I can’t find a good, reliable source for either of these. Typically, it’s an ebay thing of variable availability and ‘a friend of a friend of a coworkers ex-cousin read in the newspaper that the bartender in the next county over has some tesla packs'

Okay, Lloyd, I'm sure they do…

It’s not worth my time to recommend either of these because I’ll get a million emails asking “When will they be back in stock”?

I Don't Know…

If you want to research it on your own, go for it… but as of now, we won’t discuss something we can’t readily attain on this blog post. If that changes in the future, I’ll update so be sure you are signed up for our newsletter updates.

Q: What if I want to hack together 5 different car batteries that I found for free at the local junk yard for my solar battery bank.

Nates Answer: “You do you, beau.”

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AGM vs LITHIUM

If there is only ONE takeaway from this section that you’ll need for the rest of the post, it’s this:

Lithium can use 100% of it stated capacity AGM can use 50% of its stated capacity

That means, if you buy a 100 amp hour lithium battery, you will have 100 amp hours available for your use. If you buy a 100 amp hour AGM battery, you will only have 50 amp hours available for your use.

Now, a comparision…

Lithium vs AGM Battery Bank

There is no ‘one-size-fits-all’ answer to this, but we will try to break it down the best we can. In our Campervan, we initially had 700 amp hours of AGM batteries and have since switched to 600 amp hours of lithium batteries. Remember, 700 amp hours of AGM batteries meant we had 350 amp hours useable battery capacity. Switching to 600 amp hours lithium means we now have 600 amp hours of capacity. For the sake of this comparison, we are going to compare 200AH of usable battery capacity. That is, 2 x 100AH Battle Born LiFePO4 batteries versus 4 x 100AH Trojan AGM batteries. And while there are many, many brands out there of each type of battery, we’ve chosen these two brands because they are a) top of the line in their respective categories and b) the ones we have had personal experience with.

A Case for Lithium Batteries: Weight Savings

Battle Born LiFePO4 batteries are a direct drop-in replacement for AGM batteries, so they are very easy to install and get going. Let’s talk about some of the major pros of Lithium over AGM. The first and most heavily weighing (pun intended) on everyone’s mind when building a camper van is weight. A 100AH Battle Born lithium battery weighs in at 29 pounds, for a total of 58 pounds for a 200AH lithium battery bank. Compare that to AGM, which weighs a whopping 69 pounds each, making the total battery bank weigh in at 276 pounds. 58 pounds versus 276 pounds. That’s a huge difference!

The Cost of AGM vs Lithium Battery Bank

The biggest drawback of a lithium battery bank for your solar setup is the upfront cost. 200AH of Battle Born LiFePO4 batteries will set you back $1,900. The Trojan AGM batteries with a bank of 4 batteries for a usable bank of 200AH costs about $1,152. So choosing AGM over Lithium will save you $748. That’s a pretty big savings, right?

Well, not so fast…

Sure, the upfront cost of lithium batteries is a major investment. But let’s talk about long-term costs and replacement costs.

Lifespan of Lithium Batteries

Battle Born lithium batteries are designed to last 3,000 to 5,000 cycles. For this example, we are going to use the worst case scenario of 3,000 cycles. A ‘cycle’ is when a battery is drained, then recharged. Again, for the sake of the example, we will say a cycle is one day (use your batteries all night, then let them charge up during the day when the sun comes up). Denver gets an average of 300 days of sunshine per year, so in Denver, we would expect this battery bank to last 10 years at full capacity. After that initial 10 years (3,000 cycles), the battery is still expected to hold 75% of its capacity, meaning that you would still have 150AH usable battery bank.

Lifespan of AGM Batteries

Trojan AGM batteries are designed to last 1,000 cycles. But, according to Trojan’s website, they consider their battery to be bad once it reaches 50% of it’s capacity. Comparing that to Battle Born’s 75% capacity isn’t exactly comparing apples to apples. Instead, we will take this graph (from Trojan) and adjust it based on how long the AGM batteries will last until they reach 75%, or 150AH usable battery capacity. Based on this graph, that would mean that the AGM batteries will reach 75% capacity at around 525 cycles. Using our Denver example, that will last 1 year and 9 months. And that does coincide with the generally accepted lifespan of AGM batteries lasting around 3 years to 50% capacity.

Replacement Cost of AGM Versus Lithium Batteries

Now that we’ve covered the lifespan, let’s go back to the cost of the batteries. $1,900 of lithium batteries will last you about 10 years. $1,152 worth of AGM batteries will last you about 1 year 9 months. To get to a 10 year lifespan of AGM batteries, you’d need to purchase the entire battery bank six times. That is a total of $6,912 in AGM batteries to last 10 years. Lithium doesn’t seem quite so expensive now, does it?

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BUSBAR

MAIN PARTS OF A SOLAR SYSTEM – SEC. 4

BASIC FUNCTION

This is pronounced “Bus Bar”. These are simply a good way to organize your wires. They are essentially just an extension of your positive and negative battery terminals. Connecting more than a few wires to your battery terminals gets messy. Busbar’s are here to help organize that birds nest of a battery terminal. In addition to organization, there is a good chance you will run out of space/room on a battery terminal lug by the time all of your components are connected.

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INVERTER

MAIN PARTS OF A SOLAR SYSTEM – SEC. 5

BASIC FUNCTION

An inverter converts the 12v power coming from the batteries into 110v power useable by 110v appliances plugged into the normal household plug.

FURTHER EXPLANATION

Let’s talk about your normal household plug.

  If you want to power items that plug into a normal household plug, you need an inverter. Your normal household plug is a 110 volt plug. Look around your house.  Nearly everything here is being charged or run at 110 volts. Be sure to check out the section on “How to Size your Solar Setup” for a much more in depth thought about 110 appliances.

CHARGER A.K.A. SHORE POWER

Let’s go ahead and talk about shore power. This is where you plug your solar battery bank into a campground power pedestal to charge up on cloudy stretches. To do this, you need a device that takes 110 power and regulates it back down to 12v. This is called a battery charger or also known as a “Converter”. In my diagrams, I pretty much ALWAYS recommend Inverter/Charger combo units. My two go-to unit’s I PERSONALLY have experience with are the Victron MultiPlus Compact Inverter/Charger and the Aims 2000w Inverter/Charger. Steph and I have the AIMS inverter/charger in our campervan. We installed the Victron MultiPlus Compact Inverter/Charger in my mom’s truck camper. There is a few hundred dollars in price difference, and here’s why:

DIFFERENCE BETWEEN A CHEAP AND EXPENSIVE INVERTER/CHARGER

The AIMS 2000w Inverter Charger and the Victron MultiPlus 2000w Inverter Charger have very similar specs in regards to inverting power and charging power. The difference is in efficiency. When you invert from 12v to 110v, you lose amp hours simply making the conversion. The Victron MultiPlus 2000w Inverter/Charger is simply more efficient. Here’s the data: When the inverter is on… simply on… with nothing attached to it and it’s not actively doing anything, the Aims inverter uses about 5 amps simply to be on. The Victron inverter uses less than 1 amps to simply be on. When we have a device plugged in to our AIMS inverter, it will always use at least 5 more amps than it would if we were using a Victron unit. This means you MUST turn the Aims inverter off when you aren’t using it. If we accidentally leave the Aims inverter on overnight (say, 8 hours) we would lose 40 amp hours, which is a SIGNIFICANT amount of power. If you had a 200 amp hour lithium battery bank, that’s literally a quarter of your capacity. If you can spring for the more expensive inverter, this is why you MAY want to go for it. I asked for comparisons in my DIY Camper Van Crew facebook group, and here are the crowdsourced results I recieved:

12v FUSE BLOCK

MAIN PARTS OF A SOLAR SYSTEM – SEC. 6

BASIC FUNCTION

Wires must be protected with a fuse. If you are using inline fuses for all of your small accessory runs like lights, vent fans, usb outlets, etc, it can get messy in a hurry. The 12v fuse block is the best way to create a nice organized distribution block where each accessory run is protected with a fuse. Here is how to wire a 12v Fuse Block {DIAGRAM COMING SOON} I’ll talk more about fuses in a later section.

BATTERY ISOLATOR

MAIN PARTS OF A SOLAR SYSTEM – SEC. 7

BASIC FUNCTION

This is the method of charging your solar battery bank with your vehicles alternator so you can charge at a high rate while driving down the road.  This is particularly useful in times of overcast skies.

MORE INFO

There are a million variables here and this section will be updated as I learn a better way to teach it, so be sure you are signed up for the newsletter for updates. Here we go… I’ll break this section up into two main points.

  • Charging Batteries with an isolator
  • Charging batteries with a multi-stage charger.

Basically, what you are wanting to do here is to connect your solar battery bank with your starting battery so that your solar battery bank is taking excess charge from your alternator that your car isn’t using to drive down the road. BUT… you also want the solar batteries to disconnect from your start batteries when the car is off so your start battery doesn’t become an extension of your battery bank, killing it while you are making coffee in the morning.

BATTERY ISOLATOR

This is how you charge your batteries with your alternator. The easiest and most straightforward way to do this is by using a BIM. It does everything I mentioned above and is what I personally use on my van. It gets wired like this: {Pic coming soon} Another option is the Blue Sea ML-ACR. It does nearly the same thing, but it doesn’t cycle off and on like the BIM.

CHARGING BATTERIES WITH A MULTI-STAGE CHARGER

If you want to charge your batteries with multi-stage paremeters you will be wanting to use one of these products depending on how fast you want to charge.

WHICH IS BETTER? ISOLATOR OR MULTI-STAGE CHARGER?

Which is better? A battery Isolator or a Multi-Stage charger? I don’t have anything conclusive to say one way or another. This particular subject get’s into a lot of engineering jargon that I don’t fully comprehend and therefore can’t explain it to you, the readers of this intro to solar design blog post. When somebody was overexplaining something to him, my dad would always say…

“Spare me the labor, just give me the baby”

So, here’s the baby: I asked Sean Nichols from Battle Born Batteries which was better regarding a BIM vs Multi-Stage DC-to-DC charger. He said:

“I like the BIM. It is simpler, quieter and takes up less space. Some people want the B to B charger, which we sell that too, but it does creates a lot more heat”

So there ya go. BUT! He also said in a prior email that:

“We don’t recommend that you charge at a rate more than 50% of your bank capacity.   The battery will handle 100 amps (of charging) also but it will shorten the life-span of the battery.”

In our 2007 Sprinter with stock alternator, we typically see amps near the 100 amps mark into our solar batteries. Since this is well under the 50% mark of our 600 amp hour bank capacity, we are safe. If you only had a single 100 amp battery in your solar bank, that option may not be a good idea. Without further adieu, in a “Spare me the labor, just give me the baby” fashion: I

If you have a 100-200 amp hour battery bank, charge via the alternator using a 30 Amp Multi-Stage Charger. If you have 300 amp hours of batteries charge with the BIM.

WIRES

There are many different sizes, shapes, colors and ratings of wires.  It's pretty confusing.  For this blog post, I'll teach you to size wires and point you in the direction of the wires I recommend.

Sizing the wires for your camper solar setup can get super complicated…if you let it.  So don't let it…
I've literally already done the work for you in the wiring diagrams found at the botttom of this blog post, but I get it, some of you want to learn WHY those numbers are what they are.  So let's learn how to size your wires.

How to Size Wires for your Solar Setup

Step 1: Read the instruction manual for the item you are attempting to wire.  Seriously… most of the time it tells you exactly what size of wire and fuse to use.  Trust it.  They've got electrical engineers backing those numbers.

Step 2: Use my wiring diagrams.  I have read those numbers found from step 1 and applied them to my wiring diagrams.

Step 3: Figure it out yourself:

The following chart may look familiar if you've already been trying to find an answer to the question”How do I size my camper van wires”.  This chart, though, is a little different.

I didn't like most of the diagrams already out there, so I made my own.  Here's what you do.

  • Determine how many amps will be flowing to your appliance.  Find that number in the column on the left.
  • Determine how far your appliance will be from your power source.  Find that number on the top row.
    • (not round trip… this graph accounts for that)
  • Follow the column down and the row over to the appropriate box.
  • The two numbers are the wire gauges that will work for that run of wire.
    • Green = 3% voltage drop
    • Red = 10% voltage drop.
  • Try to stay closer to the ‘green'.  Red is still fine, but only for “Less important” things such as fans, lights, usb outlets, etc.
  • Consider ‘green' as the Ideal wire gauge.
  • Consider ‘red' as acceptable, but really try to go for green…

WHERE TO GET YOUR WIRES

Each of the wiring diagrams at the bottom of this blog post contain links to the wires I recommend, but if you need more options or are designing your own system, here are the sources that make buying high quality wires less of a pain.

ACCESSORY WIRE

For accessory wire runs like lights, fans, 12v/usb outlets, etc that are going to be 12ga – 14ga:

CLICK HERE FOR ACCESSORY WIRE

Select how much wire you want (you'll have to measure ALL of your accessory runs (and switch runs)).  Select your gauge with a ‘Duplex' wire (duplex = 2 wires, a positive and a negative).  And finally, select your color (Recommended: Red and Black)

SOLAR PANEL WIRES

For the wires coming from the solar panel, you'll be looking for 10 ga wire that is UV (sunlight) resistant.

CLICK HERE FOR RED SOLAR PANEL WIRE

CLICK HERE FOR BLACK SOLAR PANEL WIRE. 

I recommend getting a black and a red for the positive and the negative coming from the solar panel.  You'll have to measure / estimate how far it is to your solar panels.  You'll also need MC4 connectors to connect to the solar panels.

BIG WIRE OPTIONS

For all of the bigger wires in your system, you'll be looking for welding wire.  It's much more flexible than anything you can find at Lowes or Home Depot.  Here are my sources for these wires: (click into the product pages to select the length you need)

CLICK HERE FOR ALL BIG WIRE OPTIONS

CLICK HERE FOR 6ga

CLICK HERE FOR 4ga

CLICK HERE FOR 2ga

CLICK HERE FOR 1ga

CLICK HERE FOR 1/0

CLICK HERE FOR 2/0

CLICK HERE FOR 3/0

CLICK HERE FOR 4/0

FUSES

Fuses protect your system from catching on fire in the case of mishaps such as a wire rubbing through it's insulation and grounding itself to the frame of your camper. The fuse is there to protect the WIRE not the device it's connected to.  Each device SHOULD have some kind of internal overcurrent protection in addition to the fuse protecting the wire.

TYPES OF FUSES

There are 3 types of 12v fuses I recommend.  They are Spade Fuses, ANL fuses, and Re-settable Breakers.

Spade fuses are the fuses that you'll commonly find in your car's fuse panel and are typically for items run out of your distribution block and less than 30 amps (in our case.

ANL FUSES

ANL fuses come in sizes from 35 – 750 amps.  They are typically less expensive than Re-settable Breakers.  They are more reliable than re-settable breakers as they have no moving parts.  If they blow/trip, they must be replaced.  They require tools to connect/disconnect.

RE-SETTABLE BREAKERS

Re-Settable Breakers come in sizes from 25 amps up to 200 amps.  I prefer these on circuits that I know I may have to regularly ‘disconnect' for maintenance and or troubleshooting.  Honestly, the only time I don't use these is when I need a fuse/breaker that is bigger than is available.

HOW TO CHOOSE THE SIZE OF YOUR FUSES

Easiest Way

A lot of components will tell you how big of wire and what kind of fuse to use.  If this is the case, follow it.

Easy Way

  1. Find the continuous amperage of the device you are trying to power and multiply that number by 1.5, then round up to the nearest fuse size you can find.
  2. Cross check that fuse size with the maximum fuse size chart below and verify that your fuse size is below the maximum fuse size listed in the chart.

(more info: ABYC E-911)

Fuse & Wire Sizing Example

For this example, we are going to wire the 12v distribution block to the bus bar then wire a string of lights to the 12v distribution block.  All with appropriately fused with properly sized wires.

Step 1: Find the wire size for the 12v fuse block.

In description of the fuse block, it says the block has a 100A minimum.

Next, determine how far away from the power source you plan on mounting the fuse block.  We are going to mount our fuse block 10 feet away from the bus bar.

Next, we use our wire size chart to determine how big of wire we need.

100 amps over 10ft calls for a 1ga wire.

Now that we know how big of wire we are going to use, we need to determine how big of a fuse we need.

Oh, lookie there, Blue Sea tells us in the instructions how big of a fuse to use.

Now, double check that the 125A fuse requested by the fuse block in within the safe threshold for 1ga wire:
The 125 amp fuse requested by the fuse block is WELL within the maximum fuse size tolerance for our wire.

Next, we are going to determine how big of wire and fuse we need to wire a string of lights.  These are the lights we are basing our example on.  We are going to install 2 packs of these lights which will be a total of 8 lights.  The product page says these are 3 watts each.

8 x 3 = 24 total watts

24 watts / 12.6 system voltage = 1.9 amps for the whole string (which we will round up to the nearest whole number)

For the “Distance from fuse block to appliance” we are going to go with the furthest light, which, let's say, is 15 feet from the fuse block.

2 amps at 15 feet is calling for 12ga wire.

Find the size of fuse by multiplying the amps required by the device (2) by 1.5.

2x1.25 = 2.5 then we will round up to the nearest fuse size (in multiples of 5 amps) which would call for a 5 amp fuse.

Cross Reference that fuse size to verify that it's below the Maximum fuse size called out by this chart.  As you can see, 5 amps is well within the 52.5 maximum fuse size threshold.

 

HOW TO SIZE YOUR SOLAR SYSTEM

“HOW BIG OF A SOLAR SYSTEM DO I NEED?”

SIZING YOUR SOLAR SYSTEM

I took a poll in my DIY Camper Van Crew Facebook group asking HOW people determined how many solar panels and how many batteries they were going to use in their solar builds.

These are the answers I got:

  • “I sized for the biggest bang for my buck while staying within my budget”
  • “I sized my solar system according to available roof space”
  • “I performed a power audit to make a highly educated guess to how much power I use Daily”

In this module of How to Design a DIY Mobile Solar setup I will lay out the pros and cons about each of the above ways to size your mobile solar system.

In short:

  • Sizing by budget is the fastest, easiest, and most straightforward, yet least accurate.
  • Sizing by roof space still needs to have a budget set as batteries are the most expensive part of the solar build.
  • Sizing by performing a Power Audit will give you the best idea of how much power you use on the daily, which may mean less surprises later.

Nate's Recommendation: Even though performing a Power Audit is a bit confusing, we are build premiere solar power systems here. Spend a few hours on your power audit and get it right before you buy your components. This course is going to be ALL about “if we are going to do it, we are going to do it correctly”. I've personally designed the best power audit calculator on the internet to make this process as painless as possible.


Key Takeaway

A combo of all 3 solar sizing tactics is key.

  • Perform a Power Audit to find daily power usage
  • Determine max possible solar panels you can fit on your roof
  • Determine your budget and adjust your system design accordingly

Size By Budget | How to Size Your Mobile Solar System

This is the easiest way to size your solar panel setup, but it’s not necessarily the most accurate.  This works best when you ACTUALLY have a budget for your camper van build. Just winging the budget as you go?  Perhaps this isn’t the best way for you to go. Do you have $4500 to spend on solar and want the biggest bang for your buck system you can buy?  This is a great way to go (but a complete solar audit is still recommended).

Note from Nate: I am teaching you to build premiere solar setups that are modular, expandable, and will last you longer than what you are installing the system in. The smallest system I will teach you to build is in the $2250 range. If you are looking for a Harbor Freight solar build, you are in the wrong place.


Here is an APPROXIMATE list of the size of system available at various price points. “System” Refers to Solar Panels, Batteries, Charge Controller, Inverter/Charger, Wires, Lugs, Heat Shrink, etc. Hand tools not included.

  • $1,000 – None Recommended
  • $2,000 – 100 Ah AGM Battery & 200 watts of solar panels
  • $3,000 – 100 Ah Lithium Battery & 350 watts of solar panels
  • $4,300 – 200Ah Lithium Battery & 600 watts solar panels
  • $5,500 – 300Ah Lithium Battery & 600 watts solar panels
  • $7,000 – 400Ah Lithium Battery & 900 watts solar panels
  • $8,200 – 500Ah Lithium Battery & 1050 watt solar panels
  • $9,500 – 600Ah Lithium Battery & 1200 watt solar panels

Size by Roof Size | How to Size Your Mobile Solar System

Solar panels have gotten SIGNIFICANTLY less expensive over the last few years as well as more efficient. This means the difference between a 175 watt system and a 1225 watt system is less than $2000. But…1225 watts takes quite a bit of real estate on your roof! If you are in a big Class-A motorhome, this may not be a consideration, but for the rest of us, you'll have to plan how big and how many solar panels you can fit on your camper. Add air conditioners, roof vents and rooftop decks into the equation makes this quite the jigsaw puzzle. I have 4 solar panels I recommend and I have listed the wattages and sizes below:

  • 100 Watt – 47-1/16″ x 21-5/16″ [1195mm x 541mm]
  • 175 Watt – 57 7/8″ x 26 9/16″ [1470mm x 675mm]
  • 300 Watt – 64 9/16″ x 39 1/16″ [1640mm x 992mm]

Note from Nate: There is also a Renogy Eclipse panel that is even more efficient at 40 13/16″ x 20 11/16″ for 100 Watts, but it's also nearly double the price compared to the standard 100W panel. It's a fantastic panel that I DO recommend, but it's quite a bit more expensive. It's budget vs space on this decision.

Now that you have those measurements at your disposal, it's time to spend some time with a tape measure.

TIP: Recruit somebody who is good at Tetris. You'll shortly understand why.

How to Perform a Solar Power Audit

Performing a solar power audit can be a daunting task.  I am going to teach you step-by-step what you need to determine how many amp hours you can anticipate using on a day to day basis.

What Appliances Will you be Powering?

You will need to gather as many of the items you will be powering.  If you don’t physically have the items yet, you will need to look up their power consumption rates (or use the ones I have pre-filled in for you).

Not all Appliances are the Same

There are AC appliancesDC appliances, and DC components disguised as AC components.  Confusing, I know. Hang with me, I’ll break it down.

AC Appliances

These are items that you plug into your normal household plug.  These will be items like a Coffee Maker, Instant Pot, Blender, Induction Cooktop, and a Vitamix. TAKE ACTION: Gather all of these items into one pile and put a sticky note with “Table 1.1” next to them. *But wait…there is a catch…*

DC Appliances disguised as AC Appliances

There are imposters in your ‘AC Appliances’ pile.  There are likely items that plug into a normal household plug, that are actually DC appliances.  These items are like Computers, video game consoles (xbox), Cricut Die Cut machine, and printers. How to Identify these imposters:  These items will have a ‘Wall Wart’ or an inline power supply AC/DC power adapter. TAKE ACTION: Segregate these items into their own pile and label with a “Table 1.2” sticky note.

DC Appliances

These items will be wired directly to your DC Distribution block (Fuse Block).  These will be items like 12v light strips, 12v puck lights, 12v fans, Maxxair Fans, Water Pump, and 12v TV. TAKE ACTION: All of these items get their own special pile.  Label it with “Table 1.3”.

Single Charge Items

These will be items like Phones, Camera Batteries, Drone Batteries, External Charger Packs, Etc.. Basically, anything you charge up, then unplug to use. TAKE ACTION: Put these items in a pile and sticky-note it “Table 1.4”

Full Day / Per Day use Items

These are items you will let run ‘all day’.  12v refrigerator that cycles off and on, Weboost 4g booster, hot water heater are a few examples.

*Note, the hot water heater is a delicate calculation.  The figure pre-input below is for a 4 gallon Bosch unit.  It uses about 65 Amps to heat up, then it holds that heat for 12 hours-ish.  The “Quantity” on that would be for “How many times do you plan on heating up 4 gallons of water”.  Use this as a benchmark, but not a rule*

TAKE ACTION: These items go into yet another pile. Label it “Table 1.5”.

Performing a Step by Step Solar Power Audit

Now you have your 5 separate piles labeled with Tables 1.1 – 1.5, we are going to go through them, pile by pile, item by item and input the ACTUAL numbers to get you as close as you can get to a PROPER educated guess that will tell you how much solar power you will need based on how much power you use every day.


For all of these items you will need either watts and volts *OR* amps, *AND* a rough approximation of how many minutes per day you anticipate using the device.

You’ll need this spreadsheet:

Click here to Download the EXPLORIST.life Solar Audit Calculator

Adjust the columns in the spreadsheet so the words fit and get ready to enter your values.


Table 1.1 | 110v Appliances

Look for a plate on the device that tells you how many watts the appliance uses.

  1. Change the name of the Item as Necessary
  2. Input the Watts into column 2.
  3. Input the number of minutes you anticipate using the item per day.

Your spreadsheet has been pre-populated for popular appliances and power outputs.  If your needs vary, alter as necessary by altering the GREEN columns. If you anticipate NOT using an item, you can delete the values in all of the GREEN columns, or simply input ‘0’ into the ‘Minutes Used Per Day’ Column.

Example

Table 1.2 | AC/DC Adapter Appliances

Look for a sticker on the wall wart or AC/DC Converter that tells you how many amps and volts the is on the Output side of the cord. It’ll look something like this: Your spreadsheet has been pre-populated for popular appliances and power outputs.  If your needs vary, alter as necessary by altering the GREEN columns. If you anticipate NOT using an item, you can delete the values in all of the GREEN columns, or simply input ‘0’ into the ‘Minutes Used Per Day’ Column.

Table 1.3 | DC Appliances

DC powered appliances typically hide their power usage for some reason.  If you look for a label or sticker with no success, usually looking online is the best option. You’ll be looking for the wattage of the device to insert it into column 2. If you find the amps and volts of the device instead, no worries!  Table 1.3 has a built in Amps to Watts calculator. Input your amps and volts into their appropriate spot in table 1.3, look at the resulting wattage reading, and insert that wattage reading into Table 1.3, column 2 under ‘Watts”.  Change column 5 to represent how many minutes you plan on using this device.

Your Spreadsheet has been pre-populated for popular appliances and power outputs.  If your needs vary, alter as necessary by altering the GREEN columns. If you anticipate NOT using an item, you can delete the values in all of the GREEN columns, or simply input ‘0’ into the ‘Minutes Used Per Day’ Column.

Table 1.4 | Single Charge Items

For Table 1.4, you will:

  1. Change Column 1 to the Device Name.
  2. Change Column 2 to the Battery Size of the Device.
  3. Change Column 3 to the number of times you plan to charge the device per day.

Your Spreadsheet has been pre-populated for popular appliances and power outputs.  If your needs vary, alter as necessary by altering the GREEN columns. If you anticipate NOT using an item, you can delete the values in all of the GREEN columns, or simply input ‘0’ into the ‘Minutes Used Per Day’ Column.

Example

Table 1.5 | Full Day / Per Day Usage

Table 1.5 is for items that get used CONSTANTLY.  You’ll have to take a constant measurement of your items over the course of 24 hours.  This is good for things that cycle off and on like a refrigerator. The pre-populated ‘Refrigerator’ option is based on a top loading ARB 50qt 12v Refrigerator.

Your Spreadsheet has been pre-populated for popular appliances and power outputs.  If your needs vary, alter as necessary by altering the GREEN columns. If you anticipate NOT using an item, you can delete the values in all of the GREEN columns, or simply input ‘0’ into the ‘Minutes Used Per Day’ Column.

TOTAL: How Much Solar Power Do I need?

Now that you have filled in ALL the blanks with the electrical items you anticipate using throughout your normal day, check out ‘Table 1.6’.  This is how many Amp Hours you will PERSONALLY consume according to all of your inputs.

How to Size a Solar Battery Bank | Using your Solar Audit

In the last section, you learned how to estimate the amount of power you will use every day.  Now, it's time to decide on how big of a battery bank you will need. What's important to understand, is that your batteries STORE the power. Example: If it's estimated you use 300 amp hours of power every day, you need to decide how LONG you need your power to last. If you are in the perma-overcast pacific northwest and it's cloudy for 3 days straight, will your battery capacity span those 3 days? That would be looking at a theoretical 900 amp hour battery storage capacity if there is no external charging happening. If a 900 amp hour battery bank is excessive for your build, size constraints, or budget; you must adjust as necessary. In a later module, you will learn how to charge your battery bank via the vehicles alternator as well as a campground/house/generator plug as well for those overcast emergency charges.

Nate's Recommendation: Take your estimated amp hour per day measurement and set that as your absolute MINIMUM battery capacity size. Double your amp hour per day measurement, and set that as your RECOMMENDED battery bank size. Always fit as many solar panels as you can on your roof. More solar panels means a faster charge during those overcast days.

Matching Batteries to Solar Panels

How many solar panels does it take to charge a battery?

100 Amp Hours of Useable Power from a battery contains roughly 1280 watts of power (100ah x 12.8 volts = 1280 watts of power) The average hours of sunlight per day in the continental US is 6 hours. A battery holds about (100ah x 12.8 volts =) 1280 watts of power roughly. So, to charge 100 aH (useable) or 1280 watts of battery in 6 hours, you will need 213 watts of solar panels. (213 watts of solar X 6 hours = 1280 watts of stored power)

Key Takeaway: Estimate 200 watts of solar panels per 100 amp hours of useable battery capacity (100Ah Lithium or 200Ah AGM). BUT KNOW THIS: More solar panels are just going to charge your battery faster, or more adequately in low light conditions. If you have 400 watts of solar, you will charge twice as fast. Increasing the number of solar panels will also help compensate on cloudy days.

Key Takeaway #2: If you want more battery capacity than you have roof space for panels, that's fine! You will ALSO be charging from your alternator and you will also have the option to charge as needed from a plug-in at, say, a house, campground, or even a generator. This system is all about being versatile.

In short: I recommend 200 watts of solar panels per 100 useable amp hours of batteries as a base guideline.


Common Solar Setup Combos

Ah = Amp Hour 100Ah AGM Battery & 1x100 watt solar panel 200Ah AGM Battery & 2x100 watt solar panel 200Ah AGM Battery & 2x175 watt solar panel 200Ah AGM Battery & 1x300 watt solar panel 100A Lithium Battery & 2x175 wattsolar panel 100Ah Lithium Battery & 1x300 watt solar panel 200Ah Lithium Battery & 3x175 watt solar panel 200Ah Lithium Battery & 2x300 watt solar panel 300Ah Lithium Battery & 4x175 watt solar panel 300Ah Lithium Battery & 2x300 watt solar panel 400Ah Lithium Battery & 5x175 watt solar panel 400Ah Lithium Battery & 3x300 watt solar panel 500Ah Lithium Battery & 6x175 watt solar panel 500Ah Lithium Battery & 4x300 watt solar panel 600Ah Lithium Battery & 7x175 watt solar panel 600Ah Lithium Battery & 4x300 watt solar panel Systems bigger than 600Ah are still completely doable, but are uncommon. If you are over the 600Ah mark, you are likely trying to run air conditioning via solar power.

Truck Camper Solar Wiring Setup

400w Solar | 200aH Lithium Batteries

This section is where we will ‘case study' all of the parts we installed on my mom's Truck camper.  The video we put together for this one is VERY helpful, if I do say so myself, so be sure to watch it.  It's embedded below.  Below that, we talk a bit about the specs of this particular system then at the end of this section, you will find our parts list and wiring diagrams for this project.  If you have questions about this project, PLEASE leave them in the comment section on this page at the bottom.  Let's get started!

Looking for our Solar E-Book?

Due to… “red tape”, our Solar E-Book is currently unavailable.

BUT WAIT! don't go! 

I've taken everything contained in that Solar E-Book and moved it into this section of this blog post.  So, be sure to bookmark this page, email it to yourself, whatever you need to do to make sure you can find this page again, because this is where you'll find the information for the 400w, 200aH Truck Camper Solar Setup will live for now.  Be sure to browse this page, though, as it's the biggest, most in depth solar piece I've written, and leave any comments, questions, concerns in the comments section at the bottom of this page. If you want updates about this system and upcoming projects, Click here to join our newsletter.

Thanks for understanding

-Nate & Steph

This system features a 200aH 12v battery bank of Battle Born Lithium Batteries powered by 4 x 100 watt solar panels.  On the actual build, we wired the solar panels, 2 pairs in parallel, then those two in series. I don't know why we did that… Hindsight, we should have wired all 4 in series, but that change is reflected in the wiring diagrams and parts list below. Moving further around the system, we are using a Victron inverter/charger, solar controller, MBV 712 Battery monitoring and other associated fuses, wires, lugs, etc which can be found in the parts list below.

200 Amp Hour Lithium Battery Kit

Purchase Qty Item Link
2 Lithium Battery https://amzn.to/2NevVdp
1 Red 2/0 Wire https://amzn.to/2BM016R
1 Black 2/0 Wire https://amzn.to/2P3iaPe
1 5/16 x 2/0 Lugs https://amzn.to/2PDxfbC
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

400 Watt Solar Kit

Using four 100 watt solar panels

4 100 watt solar panels https://amzn.to/2o8RJMM
1 Roof Entry Gland https://amzn.to/2BeqtWD
1 MC4 Connectors https://amzn.to/2OExd1G
1 10 Ga Red Wire https://amzn.to/2ODKtDW
1 10 Ga Black Wire https://amzn.to/2vPv7Fo
1 30 Amp Breaker https://amzn.to/2vIX7uf
1 1/4″ x 10 ga Lugs https://amzn.to/2MRm5hx
1 Victron MPPT 100/50 https://amzn.to/2MgUAl8
1 8 ga Red Wire https://amzn.to/2MPGALj
1 8 ga Black Wire https://amzn.to/2vNcSQU
1 40 Amp Breaker https://amzn.to/2vLBoSw
1 1/4″ x 8 ga lugs https://amzn.to/2OJtd03
1 5/16″ x 8 ga lugs https://amzn.to/2KXExDs
4 Solar Mounting Feet https://amzn.to/2vNW5gk

Solar Power Distribution

12v and 110v inverter

Purchase Qty Item Link
1 2000w Victron Inverter https://amzn.to/2NSISNA
1 DC Distribution Block https://amzn.to/2wfrcAS
1 100 Amp Breaker https://amzn.to/2w9DVoW
1 ANL Fuse Holder https://amzn.to/2OHH86K
1 250 amp ANL fuse https://amzn.to/2p4fGoY
1 2 ga wire Red 5 ft https://amzn.to/2L1pg4D
1 2 ga wire Black 5 ft https://amzn.to/2OLhdem
2 1/4″ x 2 ga lugs https://amzn.to/2PcJ5sN
1 5/16″ x 2 ga lugs https://amzn.to/2nFlQLs
3 5/16″ x 2/0 Lugs https://amzn.to/2OKetOe
1 110v Breaker Box https://amzn.to/2N9B6zy
1 110v Breaker https://amzn.to/2COncOA
1 12/2 Romex https://amzn.to/2OezZLl
1 10/2 Romex https://amzn.to/2OlZIkQ
1 Flanged Power Inlet https://amzn.to/2OezZLl
2 Electrical plugin Box https://amzn.to/2NEHZbm
2 110 outlet https://amzn.to/2Ofamdp
1 14ga duplex wire https://amzn.to/2NGkoHs
1 #8 14ga Ring Terminal https://amzn.to/2Nb5x8c

DIY Solar Kits

Below you'll find our solar wiring diagrams and solar parts lists for MANY different DIY Solar Setups.

Be sure to Click here to get updates when we update this page by signing up for our free newsletter. Have Questions? Click here to visit the comment section of this page.

100 Amp Hour Lithium Battery Kit

Purchase Qty Item Link
1 Lithium Battery https://amzn.to/2NevVdp
1 Red 2/0 Wire https://amzn.to/2BM016R
1 Black 2/0 Wire https://amzn.to/2P3iaPe
1 5/16 x 2/0 Lugs https://amzn.to/2PDxfbC
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

200 Amp Hour Lithium Battery Kit

Purchase Qty Item Link
2 Lithium Battery https://amzn.to/2NevVdp
1 Red 2/0 Wire https://amzn.to/2BM016R
1 Black 2/0 Wire https://amzn.to/2P3iaPe
1 5/16 x 2/0 Lugs https://amzn.to/2PDxfbC
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

300 Amp Hour Lithium Battery Kit

Purchase Qty Item Link
3 Lithium Battery https://amzn.to/2NevVdp
1 Red 2/0 Wire https://amzn.to/2BM016R
1 Black 2/0 Wire https://amzn.to/2P3iaPe
1 5/16 x 2/0 Lugs https://amzn.to/2PDxfbC
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

400 Amp Hour Lithium Battery Kit

Purchase Qty Item Link
4 Lithium Battery https://amzn.to/2NevVdp
1 Red 2/0 Wire https://amzn.to/2BM016R
1 Black 2/0 Wire https://amzn.to/2P3iaPe
1 5/16 x 2/0 Lugs https://amzn.to/2LpOqKp
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

500 Amp Hour Lithium Battery Kit

Purchase Qty Item Link
5 Lithium Battery https://amzn.to/2NevVdp
1 Red 2/0 Wire https://amzn.to/2BM016R
1 Black 2/0 Wire https://amzn.to/2P3iaPe
1 5/16 x 2/0 Lugs https://amzn.to/2LpOqKp
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

600 Amp Hour Lithium Battery Kit

Purchase Qty Item Link
6 Lithium Battery https://amzn.to/2NevVdp
1 Red 2/0 Wire https://amzn.to/2BLYJbR
1 Black 2/0 Wire https://amzn.to/2P3iaPe
2 5/16 x 2/0 Lugs https://amzn.to/2PDxfbC
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

100 Amp Hour AGM Battery Kit

*The wiring diagram above features a lithium battery where the parts list below includes an AGM battery.  The wiring is exactly the same regardless of if you are wiring a Lithium battery kit or an AGM battery kit*

Purchase Qty Item Link
1 100aH AGM Battery https://amzn.to/2OaqIHm
1 Red 2/0 Wire https://amzn.to/2BM016R
1 Black 2/0 Wire https://amzn.to/2P3iaPe
1 5/16 x 2/0 Lugs https://amzn.to/2PDxfbC
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

200 Amp Hour AGM Battery Kit

*The wiring diagram above features a lithium battery where the parts list below includes an AGM battery.  The wiring is exactly the same regardless of if you are wiring a Lithium battery kit or an AGM battery kit*

Purchase Qty Item Link
2 100aH AGM Battery https://amzn.to/2OaqIHm
1 Red 2/0 Wire https://amzn.to/2BM016R
1 Black 2/0 Wire https://amzn.to/2P3iaPe
1 5/16 x 2/0 Lugs https://amzn.to/2PDxfbC
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

300 Amp Hour AGM Battery Kit

*The wiring diagram above features a lithium battery where the parts list below includes an AGM battery.  The wiring is exactly the same regardless of if you are wiring a Lithium battery kit or an AGM battery kit*

Purchase Qty Item Link
3 100aH AGM Battery https://amzn.to/2OaqIHm
1 Red 2/0 Wire https://amzn.to/2BM016R
1 Black 2/0 Wire https://amzn.to/2P3iaPe
1 5/16 x 2/0 Lugs https://amzn.to/2PDxfbC
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

400 Amp Hour AGM Battery Kit

*The wiring diagram above features a lithium battery where the parts list below includes an AGM battery.  The wiring is exactly the same regardless of if you are wiring a Lithium battery kit or an AGM battery kit*

Purchase Qty Item Link
4 100aH AGM Battery https://amzn.to/2OaqIHm
1 Red 2/0 Wire https://amzn.to/2BM016R
1 Black 2/0 Wire https://amzn.to/2P3iaPe
1 5/16 x 2/0 Lugs https://amzn.to/2LpOqKp
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

500 Amp Hour AGM Battery Kit

Purchase Qty Item Link
5 100aH AGM Battery https://amzn.to/2OaqIHm
1 Red 2/0 Wire https://amzn.to/2BM016R
1 Black 2/0 Wire https://amzn.to/2P3iaPe
1 5/16 x 2/0 Lugs https://amzn.to/2LpOqKp
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

600 Amp Hour AGM Battery Kit

Purchase Qty Item Link
6 100aH AGM Battery https://amzn.to/2OaqIHm
1 Red 2/0 Wire https://amzn.to/2BLYJbR
1 Black 2/0 Wire https://amzn.to/2P3iaPe
2 5/16 x 2/0 Lugs https://amzn.to/2PDxfbC
1 BMV 712 Monitor https://amzn.to/2P5YBG9
1 Battery Shut Off Switch https://amzn.to/2BMxGgO
1 3/8″ x 2/0 Lugs https://amzn.to/2MQJkeM
1 Bus Bar https://amzn.to/2Bi37z6

175 Watt Solar Kit

Using one 175 watt solar panels

Item Quantity Item Link
1 175 watt solar panels https://amzn.to/2vQ7axE
1 Roof Entry Gland https://amzn.to/2BeqtWD
1 MC4 Connectors https://amzn.to/2OExd1G
1 10 Ga Red Wire https://amzn.to/2ODKtDW
1 10 Ga Black Wire https://amzn.to/2vPv7Fo
2 30 Amp Breaker https://amzn.to/2vIX7uf
1 1/4″ x 10 ga Lugs https://amzn.to/2MRm5hx
1 Victron MPPT 100/20 https://amzn.to/2OHYX5p
1 5/16″ x 10 ga lugs https://amzn.to/2BSO5jA
1 Solar Mounting Feet https://amzn.to/2vNW5gk

350 Watt Solar Kit

Using two 175 watt solar panels

2 175 watt solar panels https://amzn.to/2vQ7axE
1 Roof Entry Gland https://amzn.to/2BeqtWD
1 MC4 Connectors https://amzn.to/2OExd1G
1 10 Ga Red Wire https://amzn.to/2ODKtDW
1 10 Ga Black Wire https://amzn.to/2vPv7Fo
1 30 Amp Breaker https://amzn.to/2vIX7uf
1 1/4″ x 10 ga Lugs https://amzn.to/2MRm5hx
1 Victron MPPT 100/30 https://amzn.to/2PbSJfv
1 8 ga Red Wire https://amzn.to/2MPGALj
1 8 ga Black Wire https://amzn.to/2vNcSQU
1 40 Amp Breaker https://amzn.to/2vLBoSw
1 1/4″ x 8 ga lugs https://amzn.to/2OJtd03
1 5/16″ x 8 ga lugs https://amzn.to/2KXExDs
2 Solar Mounting Feet https://amzn.to/2vNW5gk

525 Watt Solar Kit

Using three 175 watt solar panels

3 175 watt solar panels https://amzn.to/2vQ7axE
1 Roof Entry Gland https://amzn.to/2BeqtWD
1 MC4 Connectors https://amzn.to/2OExd1G
1 10 Ga Red Wire https://amzn.to/2ODKtDW
1 10 Ga Black Wire https://amzn.to/2vPv7Fo
1 30 Amp Breaker https://amzn.to/2vIX7uf
1 1/4″ x 10 ga Lugs https://amzn.to/2MRm5hx
1 Victron MPPT 100/50 https://amzn.to/2Oeequr
1 6 ga Red Wire https://amzn.to/2Qntd7n
1 6 ga Black Wire https://amzn.to/2OF2LV6
1 50 Amp Breaker https://amzn.to/2nJPXkS
1 1/4″ x 6 ga lugs https://amzn.to/2vNEAwE
1 5/16″ x 6 ga lugs https://amzn.to/2Mi7Juv
3 Solar Mounting Feet https://amzn.to/2vNW5gk

700 Watt Solar Kit

Using four 175 watt solar panels

4 175 watt solar panels https://amzn.to/2vQ7axE
1 Roof Entry Gland https://amzn.to/2BeqtWD
1 MC4 Connectors https://amzn.to/2OExd1G
1 10 Ga Red Wire https://amzn.to/2ODKtDW
1 10 Ga Black Wire https://amzn.to/2vPv7Fo
1 30 Amp Breaker https://amzn.to/2vIX7uf
1 1/4″ x 10 ga Lugs https://amzn.to/2MRm5hx
1 Victron MPPT 150/85 https://amzn.to/2MAr4q8
1 4 ga Red Wire https://amzn.to/2KZUcBY
1 4 ga Black Wire https://amzn.to/2w5xAL4
1 70 Amp Breaker https://amzn.to/2PfADsK
1 1/4″ x 4 ga lugs https://amzn.to/2MxsiSP
1 5/16″ x 4 ga lugs https://amzn.to/2Pg5Dsy
4 Solar Mounting Feet https://amzn.to/2vNW5gk

875 Watt Solar Kit

Using five 175 watt solar panels

Item Quantity Item Link
5 175 watt solar panels https://amzn.to/2vQ7axE
1 Roof Entry Gland https://amzn.to/2BeqtWD
1 MC4 Connectors https://amzn.to/2OExd1G
1 10 Ga Red Wire https://amzn.to/2ODKtDW
1 10 Ga Black Wire https://amzn.to/2vPv7Fo
1 30 Amp Breaker https://amzn.to/2vIX7uf
1 1/4″ x 10 ga Lugs https://amzn.to/2MRm5hx
1 Victron MPPT 150/85 https://amzn.to/2MAr4q8
1 4 ga Red Wire https://amzn.to/2KZUcBY
1 4 ga Black Wire https://amzn.to/2w5xAL4
1 80 Amp Breaker https://amzn.to/2MxulpZ
1 1/4″ x 4 ga lugs https://amzn.to/2MxsiSP
1 5/16″ x 4 ga lugs https://amzn.to/2Pg5Dsy
5 Solar Mounting Feet https://amzn.to/2vNW5gk

1050 Watt Solar Kit

Using six 175 watt solar panels

Item Quantity Item Link
6 175 watt solar panels https://amzn.to/2vQ7axE
1 Roof Entry Gland https://amzn.to/2BeqtWD
1 MC4 Connectors https://amzn.to/2OExd1G
1 10 Ga Red Wire https://amzn.to/2ODKtDW
1 10 Ga Black Wire https://amzn.to/2vPv7Fo
1 30 Amp Breaker https://amzn.to/2vIX7uf
1 1/4″ x 10 ga Lugs https://amzn.to/2MRm5hx
1 Victron MPPT 150/85 https://amzn.to/2MAr4q8
1 2 ga Red Wire https://amzn.to/2OH7B4l
1 2 ga Black Wire https://amzn.to/2vQfkGb
1 100 Amp Breaker https://amzn.to/2w9DVoW
1 1/4″ x 2 ga lugs https://amzn.to/2PcJ5sN
1 5/16″ x 2 ga lugs https://amzn.to/2nFlQLs
6 Solar Mounting Feet https://amzn.to/2vNW5gk

1225 Watt Solar Kit

Using seven 175 watt solar panels

Solar Power Distribution

12v and 110v inverter

Purchase Qty Item Link
1 2000w Victron Inverter https://amzn.to/2NSISNA
1 DC Distribution Block https://amzn.to/2wfrcAS
1 100 Amp Breaker https://amzn.to/2w9DVoW
1 ANL Fuse Holder https://amzn.to/2OHH86K
1 250 amp ANL fuse https://amzn.to/2p4fGoY
1 2 ga wire Red 5 ft https://amzn.to/2L1pg4D
1 2 ga wire Black 5 ft https://amzn.to/2OLhdem
2 1/4″ x 2 ga lugs https://amzn.to/2PcJ5sN
1 5/16″ x 2 ga lugs https://amzn.to/2nFlQLs
3 5/16″ x 2/0 Lugs https://amzn.to/2OKetOe
1 110v Breaker Box https://amzn.to/2N9B6zy
1 110v Breaker https://amzn.to/2COncOA
1 12/2 Romex https://amzn.to/2OezZLl
1 10/2 Romex https://amzn.to/2OlZIkQ
1 Flanged Power Inlet https://amzn.to/2OezZLl
2 Electrical plugin Box https://amzn.to/2NEHZbm
2 110 outlet https://amzn.to/2Ofamdp
1 14ga duplex wire https://amzn.to/2NGkoHs
1 #8 14ga Ring Terminal https://amzn.to/2Nb5x8c

27 Comments

  1. David

    Very well put-together and comprehensive lists here. Excellent work! One suggestion would be to add one more column that includes a short description for what the item is for, e.g. in the case of the wiring, where there are different wires sizes/types, it would be helpful to know where to use the different sizes/types of wire.

    Reply
    • Nate Yarbrough

      Hey David! Thanks for the feedback. You caught me working frantically in the middle of a post update and all of that will be coming soon! 😀

      Reply
  2. Thomas

    Hey Nate, this is such great information and instruction! That 350 amp ANL fuse? I've seen that between the battery switch and the pos. bus, and also between the pos. bus and the inverter. What is the correct location? Again, you guys do an incredible job!

    Reply
    • Nate Yarbrough

      Thanks so much! That will go between the busbar and the inverter.

      If you felt it necessary to protect the wire going between the battery and busbar, you could also put a second one there if you so desired.

      Reply
  3. Bruce J

    Thanks for all the work you guys have done putting this site and the fb DIY group and maintaining them. I was able to retire early and travel in the SW for climbing and hiking for 4 months each winter. I'm building out my 2016 MB 170 and am ready to hit some buy buttons for the rest of the materials. Following your guide I plan on 360W solar feeding 1 of the Battle Born batteries(possibly expanding to 2 later). I have no need for 2000w of A/C from an inverter. We are fine with 12VDC for our needs but…I would like to have 1) a dc-dc charger 25amps or so to charge the house battery while driving and 2) an AC battery charger 40ams or so to charge overnight at a KOA or friend's driveway in case of an extended no solar condition. It looks like a normal wet cell or AGM cell charger will work with the BB battery management system. Is that true ? Any recommendations for products I should look at ? Thanks much and happy travels ! Bruce

    Reply
  4. Janus Pitt

    Hey Nate

    Thanks for this, I'm trying to learn this stuff and this has been a great help. I've got a few questions but this one is the one I'm least sure of at the moment.

    I'm looking at the 700 Watt Solar Kit. You've got 4 x 175W 12V panels connected in series. While they wouldn't actually output exactly 48V I assume the MPPT would generally autodetect them at 48V.

    “The Smartsolar 150/85 is a great choice for controlling up to… 48V at 4800 watts”. So we've got a tonne of overhead on the input of the MPPT, it can handle way more than 700W coming in at 48V.

    So my guess for the heftier MPPT is because you've got all the battery suggestions in parallel, maintaining at 12V, because the MPPT can only handle 85A out which means 1,020W. Technically the 150/70 (840W out at 12V) would do the job but overhead is good.

    However you also suggest the 150/85 for the 875W and 1050W options. So considerably less overhead for 875W and have underspeced for the 1050W panels.

    The solution would seem to be to get a 24V battery system (either through different batteries or through putting them in series) and a 150/35 for the 700W, a 150/45 for the 875W and a 150/60 for the 1050W.

    Of course then you'd have to get a 24V inverter and make sure anything running directly off of the DC was 24V or get a step down converter for 12V stuff. Which complicates things.

    So I guess to keep it uncomplicated I'm suggesting you change the 1050 Watt Solar Kit MPPT to the 150/100 one?

    I'm working this out as I go along and have no idea if this is gibberish. But it's been helpful to me to try and nut that out. It'll be helpful if I'm completely wrong and someone tells me why too.

    Reply
    • Nate Yarbrough

      “Thanks for this, I’m trying to learn this stuff and this has been a great help. I’ve got a few questions but this one is the one I’m least sure of at the moment.

      I’m looking at the 700 Watt Solar Kit. You’ve got 4 x 175W 12V panels connected in series. While they wouldn’t actually output exactly 48V I assume the MPPT would generally autodetect them at 48V.”

      Here is the first spot your math is off. Those panels put out 19.06 panels each at max power output, so 4 of those panels in series would be about 76 amps coming into the controller which the controller would then regulate down to the 13-14.4v necessary to charge a battery.

      ““The Smartsolar 150/85 is a great choice for controlling up to… 48V at 4800 watts”. “

      That “48v” number would be for a 48v battery bank… not 48v of solar panels

      “So we’ve got a tonne of overhead on the input of the MPPT, it can handle way more than 700W coming in at 48V.”

      Indeed a bit of overhead (but not as much as you think since you were looking at that 4800w number (which is for a 48v battery bank)). The Victron 150|60 (https://amzn.to/2pNl93P) would be a better choice for 700w on a 12v battery bank.

      I likely chose the 150/85 because at the time of making the kit parts lists, the 150/60 was out of stock

      “So my guess for the heftier MPPT is because you’ve got all the battery suggestions in parallel, maintaining at 12V, because the MPPT can only handle 85A out which means 1,020W. Technically the 150/70 (840W out at 12V) would do the job but overhead is good.

      However you also suggest the 150/85 for the 875W and 1050W options. So considerably less overhead for 875W and have underspeced for the 1050W panels.”

      Apparently victron has added new controllers to their amazon store since I made these kits (only like two weekes ago… sheesh…) I'll update the lists, but for 875w kit, go with at least the 150/70 (https://amzn.to/2ITymkm). All other parts on the list would remain the same.

      The 150/85 isn't underspeced for the 1050w kit. See below…

      “The solution would seem to be to get a 24V battery system (either through different batteries or through putting them in series) and a 150/35 for the 700W, a 150/45 for the 875W and a 150/60 for the 1050W.

      Of course then you’d have to get a 24V inverter and make sure anything running directly off of the DC was 24V or get a step down converter for 12V stuff. Which complicates things.”

      Every single thing on this blog post is about 12v systems. Adding 24 or 48v systems into the mix just makes this already complicated blog post even more confusing, so I'm not even going to address 24 or 48v systems in this reply.

      “So I guess to keep it uncomplicated I’m suggesting you change the 1050 Watt Solar Kit MPPT to the 150/100 one?”

      The 1050 watt kit will be 114v (19.06×6) & 9.21 (1050/114) amps input (into the controller) which the controller would regulate down to the 14.4v that your lithium batteries will charge at, which is an output amperage of 72.91 amps out.

      Feel free to size the controller bigger if you like, but the 150/85 is still in spec for 6×175 watt panels.

      “I’m working this out as I go along and have no idea if this is gibberish. But it’s been helpful to me to try and nut that out. It’ll be helpful if I’m completely wrong and someone tells me why too.”

      Hopefully my replies helped. I think my biggest takeaway for you is to ignore 24v and 48v battery bank systems. They have their pro's, but at a basic level, 12v systems are easier to design. Also, the next biggest takeaway is ‘There is no such thing as a 12v panel'. Most '12v panels' are really closer to 20v and with a properly sized mppt controller, the voltages of the individual panel doesn't matter so much (unless you are doing math, then you have to go by what it says on the label.)

      Reply
      • Janus Pitt

        Hmm. I parsed that quote down to just the 4800W bit but it does actually say “of solar panels”:

        > The Smartsolar 150/85 is a great choice for controlling up to 1200 watts of solar panels at 12V, 2400 watts at 24V, or 48V at 4800 watts.

        Reply
        • Nate Yarbrough

          1200 watts of solar panels if you have a 12v battery bank. 2400 watts of solar panels if you have a 24v battery bank. 4800 watts of solar panels if you have a 48v battery bank.

          Reply
          • Janus Pitt

            OK, so just a badly written Amazon description. That makes more sense, cheers.

          • Nate Yarbrough

            Yeah… It definitely could have been worded a bit better. No problem!

  5. Scott

    im looking to power my 30amp camper with solar, which is better solar or wind? Both? Need help determining how to do this and how much equipment I will need. Im a year around camper and want to move to some property I bought and not have to pay the electric company. So that being said I need enough power for the summer and winter, ie. AC and Heater

    Reply
    • Nate Yarbrough

      Hey Scott! I haven't seen anybody who is happily and successfully powering much of anything on an RV with wind power. So, take that for what it's worth. You're going to need to size your system by your power consumption and your budget. AC is a power hog, but is possible with the right $$$$$. Have you performed the power audit yet? What kind of budget are you working with?

      Reply
  6. Kimberly Coble

    Nate and Steph, awesome job and thanks for all your hard work you two put into your blog and videos to bring us free content. Thanks for not only sharing content that's right/correct but also for showing us what went wrong and how you fixed it. Most people wouldn't share this info (mistakes). Great job and love your van.

    Reply
  7. phil

    hi, question about your theory of 4 x 100w solar panels in series ? wouldnt the usual ohms law apply to solar panels as it does to say batteries, where you series battery and increase the voltage but retain the current/amperage capabilities ? if so wouldnt the 4x100w panels provide you 75-80 volts (4 panel combined voltages) but only 5 amps capability ? i understand all the battery and ohms law rules but something i'm missing on the solar panel and controller side of things as you state high current capability after MPPT controller.
    I may be way off and appreciate some guidance there 🙂
    and what advantage or disadvantage would there be if you series PAIRS of solar panels and then paralleled the pairs (2 x 2 panels) paralleled to (2 x 2 x panels), would that give you greater capacity to charge the house battery, theory being more amps (parallel pairs) ??

    Reply
    • Nate Yarbrough

      hi, question about your theory of 4 x 100w solar panels in series ? wouldnt the usual ohms law apply to solar panels as it does to say batteries, where you series battery and increase the voltage but retain the current/amperage capabilities ? if so wouldnt the 4x100w panels provide you 75-80 volts (4 panel combined voltages) but only 5 amps capability ? i understand all the battery and ohms law rules but something i’m missing on the solar panel and controller side of things as you state high current capability after MPPT controller.
      I may be way off and appreciate some guidance there 🙂

      Yeah, that's kind of confusing and you've got it…halfway… 5 amps at 80 volts (5 amps * 80 volts = 400 watts) coming into the charge controller would convert over to (400 watts / 14v (charging voltage) = 28 amps into the battery. If you want visuals of this, it's in this section: https://www.explorist.life/diy-campervan-solar/#charge-controller

      and what advantage or disadvantage would there be if you series PAIRS of solar panels and then paralleled the pairs (2 x 2 panels) paralleled to (2 x 2 x panels), would that give you greater capacity to charge the house battery, theory being more amps (parallel pairs) ??

      There would basically be no advantage to doing it like that.

      Reply
  8. Jim

    Hi – On the 525 Watt system which circuit breaking is coming from the solar and which is coming from the controller??? Excellent video and information on the blog – Thanks

    Reply
    • Nate Yarbrough

      The smaller of the two breakers will be on the solar panel side of the solar controller.

      Reply
  9. Punit

    solar panels in series suffer from one condition. If any panel is partly blocked the efficiency of the solar setup drops to the level of the least efficient panel in the setup.

    for a parallel setup this is not the case. However a parallel setup has a different set of issues: more current which requires thicker wires (or smaller wire gauge size) and larger current for MPPT controller to handle.

    Some people therefore choose to use a series-parallel combo.

    any thoughts ?

    Reply
    • Nate Yarbrough

      There are hundreds of thousands of ways to design a solar setup. If I catered this blog post to every single possibility, it would become less and less helpful. What you are suggesting is indeed a way to wire solar panels, but it does complicate the system slightly. Most of the people I have talked to in real-world scenarios (Steph and I included) have not had issues due to partial shading. Either we are in the shade or in the sun. There is rarely the awkward middle ground. If there IS an awkward middle ground, we will pull forward 5 feet or back up 5 feet until the problem is solved.

      That's why I make all of the wiring diagrams at the bottom of this post; panels in series.

      Now…if this were for a tiny house or something more stationary and you had partial shading that happened every single day, that's where I could see altering the wiring diagram.

      Reply
  10. Chuck Heiry

    Nate, I have a couple of specific questions about my DIY design for me Sprinter electrical system. Is this “Comment” section away for us to communicate or is there a better way?

    Reply
    • Nate Yarbrough

      Hey Chuck! This comment section is indeed the best way.

      Reply
  11. David

    Nate is the 14ga duplex wire necessary?

    Reply
    • Nate Yarbrough

      Hey David! Would you mind rephrasing your question with, perhaps a little more context?

      Reply
  12. LaVerne Lindsey

    Hello. I have a 1988 RV and wanting to put solor on it. I have brought the kit but not understanding how to link everything together. I understand how to meet up the solor to the inverter and to the house battery through the controller and how to hook up the main battery to the controller. Where I'm confused is how do i set up the old setup to the new one. I have a generator involved.

    Any assistance is greatly appreciated
    Thank you LaVerne

    Reply
    • Nate Yarbrough

      Hey Laverne! The best way for me to help out on this would be for you to draw a wiring diagram as accurately as possible as to what you've got going on so I can make a recommendation.

      Reply

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