When we first started thinking about our vanlife electrical system and buying our components, we had a lot of questions. We researched online, read other van build blogs and forum posts, and watched Youtube videos. Some were very helpful, but many left us with a swirl of even more questions.
We were learning a lot about circuits and electrical systems, but we were also overwhelmed by all the new knowledge coming at us from all directions. Getting electricity in a van is such a vital part of any van build, and we wanted to get it right.
We longed for a resource that told us: Buy this. Connect it like this. Here’s a diagram.
This post is an attempt to make such a resource.
In this post, we go over exactly what we bought, exactly how we connected everything, and we even have pictures and diagrams (yay)!
For those of you interested in further reading, we also include links to blog posts and other resources that helped us out along the way.
We want this post to be as accurate and helpful as possible, so if we get something wrong or you want us to clear something up, let us know in the comments!
Obligatory Disclaimer: This post describes what we did with our own system based on our own research, and we hope you’ll find it helpful. That said, we are NOT ELECTRICIANS. Working with electricity in any form can be dangerous. It’s always a good idea to read the manuals for all of your components and consult with a licensed electrician before performing any electrical work.
Mega List of Everything We Used in Our Electrical Install
Main Components
Lithium iron phosphate (LiFePO4) batteries are THE best choice for modern camper vans.They last much longer, charge faster, and can be fully discharged without damage. Battle Born batteries are made in the US, and designed specifically for mobile living and off-grid dwellings.
Our #1 recommended battery choice.
Lights, Dimmers, and Outlets
Wiring and Connectors
Fuses and Cutoff Switches
If you buy a premium solar kit from Renogy, it should come with two 30A/40A ANL fuses/holders, as well as the MC4 inline fuse/holder. You may still need additional ANL fuses for components that require a larger fuse, like your inverter or battery isolator.
Essential Tools
How to Charge Your Batteries While Driving
There’s one more component that we’ve discovered is vital to have on the road: a smart battery isolator.
We have the Keyline Chargers 140-Amp Smart Isolator in our van, and it has worked flawlessly for us.
Note: If you have a newer vehicle or are trying to charge a LiFePO4 battery bank, you will need a DC-DC battery charger like this one from Renogy (make sure to use the coupon code GnomadHome at checkout for 10% off your purchase).
A smart battery isolator allows you to charge your auxiliary batteries from your vehicle’s alternator while driving. This is a great supplement to solar panels, especially if you’re spending time in overcast or heavily forested environments where you don’t get as much sun.
Budget Note
If you only have a few hundred dollars to spend on your electrical system, we recommend starting with a good battery, a smart isolator, and an inverter. You can always add solar later.
Check out this detailed post for more information on battery isolators, what kind to get, and how to install one.
What Does All This Stuff Do?
That’s a pretty intense list. But don’t worry, it’s really not all that complicated. Let’s break it down from a bird’s eye view.
The Sun
It all starts with the sun. The sun not only gives us life, it also constantly beams energy to us here on Earth. Using science, we can convert this energy into electricity to power vanlife!Solar Panels
Solar panels absorb light from the sun, convert it into electricity, and send it on to the charge controller.Charge Controller
The charge controller regulates the flow of electricity from the solar panels and uses it to charge your batteries.Batteries
The batteries we use store electricity at 12-Volt DC (direct current), which can power your lights, exhaust fan, fridge, USB/cigarette lighter outlets, and anything else that runs on DC. In our system, the electricity is fed from the batteries back to the charge controller, which then distributes it outward.Inverter
If you want to power something like a computer or other complex electronics that require a 3-pronged wall outlet, you’ll also need an inverter, which converts 12-Volt DC to 110-Volt AC (alternating current). This is connected directly to the battery.
That’s basically what’s going on in a 12-Volt van solar power electrical system. Everything else just connects the dots.
How Much Electricity Do You Need?
It’s a good idea to think about how much electricity you’ll use when deciding how many solar panels you need and how big your batteries should be. This can get a bit complicated, especially since there’s a lot you just don’t know about your usage if you’ve never lived in a van before.
But, if you want to make sure you have enough electricity to meet your daily usage while also not paying for more than you need, then going through the exercise of sizing your system is the best thing to do.
How to Size Your System in 3 Easy Steps
Step 1: Calculate the amount of electricity you plan on using in Watt-hours (Wh).
This sounds a bit scary, but it’s actually pretty easy.
First, list out all of the devices/appliances/components you plan on using, along with the amount of Watts each of them draws (this information should be easily available in the component’s instruction manual, or on the internet).
Next, calculate how many hours you plan on using each component. Multiple the Watts by the hours and you have Watt-hours!
Watts x Hours = Wh
So, if your lights use 5 watts and you have them on for 5 hours each day, their power consumption is 25 Wh per day (5W x 5h = 25Wh).
Step 2: Determine the amount of battery capacity you need.
For this example, let’s pretend all your electrical components use 1200 Wh each day.
Battery capacity is measured in amp-hours (ah), so to figure out how big your battery needs to be, convert the 1200 Wh of power consumption into ah by dividing by the system voltage (12V).
1200 Wh / 12V = 100ah.
Based on this calculation, you would need 100ah of battery. But this also depends on the type of battery that you have.
You see, most types of batteries shouldn’t be depleted below about 50% (this goes for regular flooded-lead-acid, AGM, and gel batteries). If these batteries below about 50% you risk shortening its lifespan and/or damaging them. So in reality, the usable capacity of these types of batteries is about half (i.e. 100ah battery = 50ah of usable capacity).
The exception here is LiFePO4 (lithium iron phosphate) batteries. These batteries are more expensive than regular batteries, but you can deplete them 100% (they’re also lighter, safer, and last longer than regular batteries).
So how much battery capacity do you need to accommodate 100ah of usage per day?
- Regular batteries (FLA, AGM, or Gel): 200ah of battery capacity will cover 100ah of usage, since you never want to deplete these batteries below 50%.
- LiFePO4 batteries (lithium iron phosphate): 100ah of battery capacity will cover 100ah of usage, since these batteries can be depleted 100%.
Of course, these above numbers assume that you’re dealing with perfect charging conditions and that you never go over 100ah of usage. Reality always ends up a bit different, so if you have the budget it’s a good idea to add in some cushion.
Step 3: Figure out how many solar panels you need to fully charge your batteries each day.
Solar panels are in watts, so we’ll again use our 1200 watts of power consumption. Let’s divide that by the average amount of full sunlight per day to get the amount of solar panels we need (5 hours is a good general estimate, although you’ll get more in the Southwest and summer, and less in the North and in winter, etc.).
1200 Wh / 5 hours = 240 Watts. So, 240 Watts of solar panels should, in theory, fully charge your batteries each day and accommodate your power consumption.
Except that it never works that way. There’s shade, and clouds, and less sun in winter, and days where you consume more power than others. Something like three 100-watt panels would be a much safer bet.
Budget-Based System Sizing
Sizing your system appropriately can be challenging, especially if you’ve never lived in a van before. There’s just a lot you won’t know about your real-world usage of electricity in your van, and a lot you won’t be able to foresee before you hit the road.
Another method is taking a budget-based approach to your electrical system, and adding capacity as-needed.
If you have a barebones budget, you don’t need a huge, expensive solar setup. But if you can afford it, having a large system will make your life easier and means fewer compromises in your electrical usage.
Here are the main components we recommend for different budget levels:
Barebones Budget
If you have a tight budget, starting off with a good inverter, a battery, and a battery isolator should meet very basic electrical needs (charging phones/computers, some lights). You can always add on solar capabilities later if you need to.
Midrange Budget
This midrange setup gets you started on the right foot, with more battery capacity and 200-watts of solar. This setup is completely expandable, so you can add more panels later if you need to.
Higher Budget
If your budget allows, a system this size should cover most electrical needs (unless you’re trying to run an AC or electric heater). Over 300Ah of battery capacity, DC-DC battery charger, 2000W inverter, and 400-watts of solar mean you’ll never have to worry about plugging in!
Highest Budget
Top of the line (and better-performing) LiFePO4 batteries add a serious upgrade here, and the 2000W inverter charger allows you to plug in as needed (which can come in handy in a pinch).
Choosing Solar Panels and Batteries
Now that you know what size system you need, it’s time to select the actual components.
What We Went With
For our solar setup, we decided to go with Renogy’s 400-watt solar kit with 40A MPPT charge controller. Renogy’s premium solar kits come with just about everything you need for a solar install. In addition to the panels and the charge controller, these kits include wiring, mounting brackets, fuses, and a Bluetooth module. For the money and ease of install, it’s tough to beat these kits.
Everything you need to add solar to your van. Including solar panels, mounting brackets, MPPT charge controller, fuses, and wiring. Available in 100W, 200W, 400W, 600W, and 800W.
Enter discount code GnomadHome for 10% off at Renogy.com
For our batteries, we went with two VMAX 155ah batteries (for 310ah of total capacity). These batteries have extra thick plates on the inside, which helps increase their reliability and durability. If you don’t need batteries this big, VMAX makes AGM batteries in a range of sizes, including 125Ah.
Super rugged AGM battery in 155ah capacity. If you can't afford lithium, these are the way to go.
![[BUNDLE] 2 VMAX 155Ah AGM Deep Cycle Batteries](https://gnomadhome.com/wp-content/uploads/2022/10/51j9tioUbL._SL500_.webp "Epic Guide to Van Life Electrical & Solar (How to Get Electricity in a Van) 49")
Need two batteries? Save by bundling two VMAX batteries together. These batteries are super rugged, and are the way to go if you can't afford lithium.
Note: When we built our initial system back in 2016, lithium (LiFePO4) batteries were out of our price range, and didn’t make as much sense economically. However, lithium batteries are only getting better and cheaper, and if you have the budget for them, they are easily the way to go. They’re safer, they charge faster, and they have double the usable capacity. We’ve since installed them in other vans, and we highly recommend them.
Although we bought a 400-watt solar kit, we were only able to fit three of the panels on our van’s roof, but we’ve got the fourth stashed under the bed.
We built a foldout PVC frame for this “extra” panel so we can prop it up and plug it in when needed. This lets us park in the shade on really hot days while still charging our batteries from the sun.
Is our system too big? We don’t think so.
Having this much solar allows us to be 100% off-grid, and we rarely have to worry too much about our power consumption. We’ve met people on the road with smaller systems that regularly worry about making sure they have enough juice to keep their fridge running.
And even with a system this big, we have run low on juice in certain scenarios. If we’re in overcast climates or heavily forested areas (or both) for more than five days or so, and if we’re staying in one place and not driving much, then our batteries start to get down to the 12.0V-12.2V range in the morning. But because of our system size, we can boondock longer in the same spot, in all weather and environments, and still do everything we need to do.
Can you get by with less? Absolutely.
If you’re tighter on funds, Renogy’s 200-watt kit paired with a smart battery isolator is a great place to start. You can always add more panels later.
Whatever you go with, we recommend getting an MPPT charge controller instead of a PWM controller. MPPT controllers are able to squeeze higher efficiency from your solar panels. They’re supposedly up to 25-30% more efficient than PWM controllers. MPPT controllers are more expensive up front, but they’ll allow you to stretch your system much further.
Basic Circuitry: What You Need to Know
Going too deep into basic electronics is beyond the scope of this post, but it definitely helps to visualize how a simple circuit looks when designing your system.
Here’s a diagram of a basic DC circuit:
Closing the switch completes the circuit and allows electricity to flow between the battery and the lights. One common analogy used here is that of a water pipe. If there’s a break in the pipe, water won’t be able to flow.
A fuse is an intentional weak point in a circuit. It’s there for safety. If too much current flows through the circuit, the fuse will “blow” and break the circuit.
“Grounding” in van life electrical is a connection to the vehicle’s chassis. This is also for safety. In our install, we grounded the battery and the inverter.
Designing Our System (With an Awesome Wiring Diagram!)
In designing our system, we leaned heavily on wiring diagrams we found on the internet, particularly the one in this post by Van Dog Traveller (his ebook has even more detailed diagrams).
But all the diagrams we found gave us a lot of partial information or only halfway applied to our system, and led to some confusion on our part.
After all of our research, we couldn’t find an all-encompassing diagram that showed us exactly how everything in our system fit together. So we made one.
We highly recommend diagramming your system so you know exactly how everything is supposed to connect. Just drawing it out really helps you think it through and get it straight in your head.
Making Sure You Have the Right Size Wires and Fuses
This can be a bit confusing if you’re new to electrical work. But it’s important to get it right if you don’t want to deal with any electrical or safety issues down the road.
Below, we break down exactly how to calculate the wire sizes you need, and give you some tips on selecting the right fuses for your circuits.
Choosing the Correct Wire Sizes
Choosing proper wire sizes is an important step in any electrical install. If your wires are too thin, it can be a significant safety hazard. If your wires are too thick, you’ll be spending more than you need and your wiring will be harder to work with.
Note: In the United States, wire size is measured in American Wire Gauge (or AWG). AWG gauges may be different than wire gauges used in other countries. Since we are in the US, we used wires measured in AWG for our electrical install.
The size wire that you choose should be based on the amount of current going through the wire and the length of the wire run. You want to use a wire size that’s thick enough to safely handle the electrical current without experiencing too much voltage drop.
How do you figure out the max current that will be going through your wires?
Your lights, appliances, and other electronics should have their max current available in their technical specifications.
For DC appliances this should be listed in amps (max amperage). If your component specs lists this in watts, divide that number by the system voltage (so divide by 12 for a 12V DC system).
How do you figure out the length of your wire run?
First, you’ll need to measure the distance the wiring is going to travel. Then double it.
What?! Double it?! Yup. When calculating wire sizing for DC systems, the wire length refers to the total length of both the positive and negative wire.
So, if you’re wiring an outlet that will be 5 feet from your fuse box, your wire length is actually 10 feet – 5 for the positive wire, and another 5 for the negative wire to complete the circuit.
Okay, so now that I know my max current and wire length, how do I figure out what wire size I need?
Blue Sea Systems has an awesome “Circuit Wizard” calculator on their website that can help you determine the proper wire size for what you need.
Simply enter the system voltage, the max current, and the total wire length. The calculator will spit out the recommended wire gauge for you:
We also found this helpful automotive wire sizing calculator from Wire Barn that shows you more detail on what gauges will or won’t work, as well as other pieces of information like voltage drop for each.
Here’s an example of choosing the correct wire size using our Acegoo 12V LED lights
We have a 12V electrical system, so we’ll use that as our system voltage.
System voltage = 12V
Per the tech specs on our Acegoo 12V recessed LED lights, they have a max current of 3W per light. To convert that to amperage, we divide by the system volume (3W / 12V = 0.25A).
Each light is wired individually to the switch, so we need wire that can handle 0.25A of current.
Max current = 0.25A
We planned on installing each light no more than 6-10 feet from the switch (we’ll assume 10 feet to be on the safe side). To get our total wire length, we’ll multiple 10 feet by 2 to account for both the positive and negative wire.
Wire length = 20 feet
Plugging all these numbers into the Circuit Wizard spits out a recommend wire thickness of 22 AWG. (We ended up using 18 AWG to be extra safe).
But that’s not all. We also need to wire the dimmer switch down to the fuse box. Since we have sic LED lights wired to one dimmer, we need to multiply the light current by 6 to get our max current:
Max current = 1.5A
The distance between the dimmer and fuze box is about 4 feet. Double that to get the total wire length:
Wire length = 8 feet
Plugging these numbers into the Circuit Wizard gives us a recommended wire gauge of 18 AWG. (We ended up using 14 AWG here, again to be safe, and so we could use the same wiring for our dimmer switches and outlets).
You’ll want to run this same calculation to get the proper wire sizes for all your components. In general, the wiring for things like lights, outlets, fan, fridge, and other DC components will be probably between 12 AWG and 18 AWG.
You’ll need much thicker wiring for your batteries, inverter, and ground cables. Again, you’ll want to calculate this yourself based on max current, length, and manufacturer recommendations. We used mostly 4 AWG battery cable for the batteries, and thicker 2 AWG cable for the inverter and ground connections.
Choosing the Correct Fuse Sizes
Choosing the right fuse sizes for your circuits is very important for safety. A fuse is an intentional weak point in a circuit. If the current in the circuit ever gets dangerously high, the fuse will “blow,” breaking the circuit and saving you from some major electrical problems.
For your electrical loads (lights, outlets, fan, fridge, etc.), we recommend wiring everything into an automotive blade fuse box and picking up a set of blade fuses.
As a general rule, choose fuses that are above the max current of your circuit load, but below the amperage rating of your wiring.
Going back to our LED light example – the total max current of our light circuit is 1.5A. So, we fused this circuit with a 2A fuse. This is above the max current of our lights, but well below the amperage rating of the 14 AWG wiring we used.
For larger items like your batteries and inverter, you’ll want to use a different type of fuse. We used ANL fuse holders with the proper fuses for our batteries and inverter, and an inline MC4 fuse holder to fuse our solar panels.
Make sure to check the manuals for your solar charge controller, inverter, and batteries for manufacturer-recommended fuse sizes.
Note: Renogy’s premium solar kits include ANL fuses/holders, as well as an MC4 inline fuse holder. Then you’ll just need some larger ANL fuses for your inverter. And, if you use the coupon code GnomadHome at checkout, you’ll get 10% off your purchase!
Cutting and Crimping Wires
How do all these wires connect to each other and your components? With crimp connectors!
We used three kinds of crimp connectors for the thinner gauge wiring (22-10 AWG) in our van build: ring terminals, 1/4″ female quick disconnects, and butt splice connectors.
Pick up a basic electrician’s multi-tool and you’ll be crimping wires in no time. If you want to get a little more serious, you can pick up a ratcheting crimp tool for no-nonsense crimps that you know are strong.
Read more: Check out this article for a tutorial on crimping wires.
Crimping Battery Cable
Crimping terminals onto battery cable (8 AWG and thicker) is a little more difficult, and requires specialized crimping tools.
The most basic type of crimper for battery cable is a hammer-style crimp tool (we used one of these for our build). This type of crimper is inexpensive, portable, and fairly easy to use, but it’s also easier to crimp improperly. There are also mechanical crimp tools and hydraulic crimp tools. Hydraulic crimp tools should give you best results, but they’re also bulky and expensive – which means it might not make sense if you’re only using it for one build.
If you don’t feel like messing with crimping your own battery cable, you can buy pre-made battery cables in various sizes with ring terminals already attached. The downside is that you’ll lose some flexibility in the placement of your electrical components, and the cost can add up quickly. Yet another option is to order custom-length cables.
Connecting the Dots: Step-by-Step Installation of Our Electrical System
Here’s the part where we go through how we installed all the pieces of our electrical system. Between cutting and crimping wires, arranging and organizing components, making mistakes and figuring things out as we went, this whole process took us a few days.
Mount and Wire the Solar Panels
Important: DO NOT hook up your solar panels to the charge controller until the batteries are connected.
The first thing we did was mount our solar panels to our van’s roof and wire them together in parallel using a Signstek Y-branch wiring connector.
For parallel wiring, all the positive wires go together and all the negative wires go together.
We decided to wire our panels in parallel for a few reasons:
- Parallel allows us to hook up the three panels on our roof and connect our fourth panel whenever we want.
- With panels wired in series, if some shade gets on one of the panels the electrical output of the entire system will be affected. With panels wired in parallel, shade will only affect that one panel.
There are advantages and disadvantages to both parallel and series. Renogy has an awesome guide on the differences.
After we mounted our panels, we fed the wires inside the van and ran them through some conduit down to where we planned to put all of our electrical components.
Mount the Charge Controller
Next, we mounted our charge controller to the wall inside our van. Renogy recommends leaving a few inches of space all around for ventilation.
Wire Batteries Together in Parallel
If you have more than one 12V battery, wiring them in parallel is the way to go for a van system. To do this, connect the positive terminals together, then connect the negative terminals. We used 4 gauge battery cable for this.
Ground Batteries to Chassis
Next, we grounded our batteries to the vehicle chassis. We used 2 gauge wire for the ground connection. We screwed the ring terminal directly to the vehicle frame using 1-⅝” self-tapping screws and shake proof lock washers. The connection is rock solid.
How to Properly Wire Your Batteries
When you connect everything to your batteries, make sure you do it on opposite sides of your battery bank. What does that mean exactly?
Attach all of your positive wires to the positive post of one battery, and connect all of your negative wires to the negative post of the other battery. This allows your batteries to charge and discharge at the same rate and will help keep them healthy.
Check out this page for helpful diagrams showing how to wire together different sized battery banks in both parallel and series.
Wire Charge Controller to Batteries
For this step, we used the leftover 8 AWG wire that came with Renogy’s kit, crimping on ring terminals as needed. First, we ran 8 AWG wire from the positive battery terminal on the charge controller to one side of a heavy duty on/off switch. This will let us kill the connection to the battery if we ever need to.
Note: DO NOT disconnect the battery while the solar panels are hooked up to the charge controller. Whenever we need to cut off power to work on the system, we always make sure to disconnect our solar panels first. In fact, it may be a good idea to install a second cut off switch for the solar panels.
Next, we ran more 8 AWG wire from the other side of the switch and connected it to one side of an inline fuse holder. The fuse should match the current rating of the charge controller (i.e. a 20A fuse for a 20A charge controller. We used a 30A fuse). Then, we ran 8 AWG wire from the other side of the fuse holder to the positive post on our battery.
Now that we had the positive connected, we ran a wire from the negative battery post and connected it to the negative battery terminal on the charge controller.
As soon as we made the connection, the charge controller turned on. Exciting!
Make Sure to Fuse Your Solar Panels
Renogy recommends adding a fuse in between your solar panels and your charge controller. The easiest way to do this is using Renogy’s inline MC4 fuse/holder, but any type of 40A inline fuse should also work.
Note: Renogy’s premium solar kits include all fuses that you need for wiring up your solar, including an inline MC4 fuse/holder and two ANL fuses/holders.
Use the coupon code GnomadHome at checkout for 10% off solar kits and more at Renogy.com!
Wire Solar Panels to Charge Controller
This was simple enough. We inserted the positive wire from the solar panels into the positive solar terminal on the charge controller, then did the same with the negative wire. Now the solar panels were charging the batteries!
Wire the Load Terminals to the Charge Controller
We ran 8 AWG wire from the positive load terminal on the charge controller to the positive terminal on our blade fuse block.
Next, we ran another 8 AWG wire from the negative load terminal on the charge controller and connected it to the negative terminal on our fuse block.,
To get your 8 AWG wire, you can use leftover wiring from the solar panels and crimp a ring terminal onto one end.
Installing the outlets was much simpler.
We first drilled holes and mounted them in place.
Then we crimped quick disconnects onto both red and black wires and connected them to the back of the outlets.
We attached the other side of the positive wire to the blade fuse box using a quick disconnect, while the negative wire attached to the negative bus with a ring terminal.
The fan was the simplest.
Using butt connectors, we crimped additional wire onto the positive/negative wires coming to the fan. We then attached the positive wire to the fuse box using a quick disconnect, and attached the negative wire to the common bus bar using a ring terminal.
Wire Lights, Dimmer Switches, and Fan
Next, we connected our LED ceiling lights, vent fan, and outlets to the system. We used 18 AWG wire for the LED lights and 14 AWG wire for the outlets and fan.
Before we hung the ceiling we had attached wires to the lights and fan using twist connectors, and wrapped it with electrical tape to prevent the connection from vibrating loose.
Then we labeled the wires and ran them through conduit down to the electrical area. So all we had to do now was connect everything together.
We hooked up the lights to dimmer switches.
We rigged up one dimmer switch in the front controlling a set of six lights, and another dimmer in the “bedroom” controlling two lights.
The awesome dimmer switch we used comes with three wires: a positive, a negative, and a ground.
Using a twist connector, we twisted together the positive light wires, the positive wire from the switch, and another wire that ran down to the blade fuse box.
We then twisted together the negative light wires and the negative switch wire.
We spliced the “ground” wire from the switch to a separate wire that connects to the negative bus bar.
Insert Blade Fuses into Fuse block
Adding fuses into the fuse block completes the circuit and makes sure your system is protected. When designing your system, you’ll want to base your fuse sizes on the max amperage of the circuit.
For example, if your fan circuit draws 3A, you’ll want to use a fuse as close to 3A as possible without going under it.
Hit the Switch Aaaaannnndd……
This is when things should turn on. But for us, nothing happened. We tried turning on the fan, turning on the lights – nothing.
It turned out that we had our charge controller set to cut off power to the load. If you get to this point and nothing turns on, check your charge controller settings!
Once we got the settings correct everything worked beautifully. The lights dimmed on and off, the fan turned on, the outlets charged our phones.
Wiring the Inverter to the Battery
We mounted our inverter to the outside of the partition that separates the electrical enclosure from the storage area under the bench.
The inverter connects directly to the battery.
First, we ran wire from the positive battery post to a heavy duty on/off switch so that we can cut the power to the inverter if needed.
Next, we ran wire from the switch to an inline fuse holder with a 100A fuse. We used one of Renogy’s ANL fuse holders and replaced the 30A fuse it came with. From there, we connected a wire from the fuse holder to the positive terminal on the back of the inverter.
The negative wire goes directly from the negative battery post to the negative terminal on the back of the inverter.
Finally, we grounded the inverter to the van’s chassis using self-tapping screws and shake proof lock washers.
The inverter has regular 3-pronged outlets on the front. You can plug your AC devices directly into these outlets, or run an extension cord to a power strip or AC outlet elsewhere.
If you prefer to have hardwired outlets, you can cut off one end of an extension cord and wire it to a standard wall outlet (positive, negative, and ground), which you can then mount in an outlet box and attach anywhere you want. The intact end of the extension cord plugs into the inverter to draw power.
Pro Tip: Keep Things Organized!
Trust us, your life will be so much easier (and safer) if there isn’t a jumble of live wires spewed all over the floor of your van.
We concealed all of our electrical components in a compartment under the seat of our flip top bench.
We used ½” metal wire straps (wrapped in electrical tape) from Home Depot to organize the thick battery cables, and smaller wire clips and zip ties to hold down the smaller wires.
This keeps the wires out of the way, and also takes tension away from the electrical connections so they’re less likely to come loose while driving.
Awesome Resources for Further Reading
- 12V electrics and wiring for my campervan conversion (Van Dog Traveller)
- From Van to Home ebook (Van Dog Traveller)
- Basics of Solar Power (CheapRVLiving)
- Road Less Traveled Solar Post
- Battery Wiring Diagrams
- Renogy’s Resource Page (TONS of info and manuals)
- RV Solar Power Made Simple (Road Less Traveled)
- How to Crimp Cables and Wires (Instructables)
- Jack and Jill Travel Solar Post
- RV Electric Power for Dry Camping (system sizing)
- Youtube Video Showing Installed Components (Campervan Cory)
Conclusion
That’s just about everything we did for our electrical install. We tried to answer all the questions we had when we started out, and some questions that we had right up to the installation. If there’s something we didn’t cover, or you have a question, or we got something wrong, let us know in the comments!
We’re supremely pumped to have power in our van – it definitely makes those late night van build sessions a lot easier!
Stay tuned for more build updates as we go into building our awesome furniture. And don’t forget to follow us on Instagram @gnomad_home and on Facebook at Gnomad Home.
I am intending on using propane where I can to keep my electricity usage low. However a propane fridge and a water heater both will have a circuit board. Does anyone now the approximate current draw on these boards. I do not expect it to be much.
Hi,
First of all, thanks a lot for all the information. I’m almost finished with my set-up which is almost identical to yours and everything is running like a charm. Just one question left: I have grounded the battery – to the chassis and I want to ground my inverter (1000 Watt) to the chassis too but it’s quite hard to find a spot where I can connect it. Would it work to connect the ground connection of the inverter to the negative of the battery? Eventually that negative of the battery is connected to the chassis.
KR, Marc
Hi Mark, the system would likely function, but you really want a direct connection to the chassis, especially with the inverter. You don’t want the shortest path to ground to be through you, otherwise you put yourself at risk of getting a 120V electric shock. Hope that helps!
Hey there! In the section/note about disconnecting the solar panels before disconnecting the battery from the charge controller, are you saying you wish you had another disconnect switch between the panels and the charge controller to disconnect this first before disconnecting the switch between the charge controller and the batteries? If so, what do you do now to disconnect the panels before disconnecting the charge controller->battery?
Hi Jill, thanks for reaching out! Yes, we would recommend having an easy way to disconnect the solar panels if needed. You could do this with a disconnect switch, or you could use a breaker (make sure to get a reputable brand like Blue Sea, not a no-name brand off of Amazon), which provides both overcurrent protection like a fuse and can act as a switch. Hope that helps!
John
Hello! We are also building out a van and this post is so helpful!
We would like to run an extension cord (Marinco 15A Marine Grade Locking Extension Cord) from our inverter to our kitchen to power just one device at a time (we only have two 120v appliances).
Is it safe to do this? Do you have any other resources about how to utilize the inverter when we plugging directly into it isn’t an option for us?
Thanks!
Hi Marty, it’s absolutely safe to run an extension cord from your inverter. We kept our inverter tucked away with the rest of our electrical components and plugged a power strip into it, which we mounted in a convenient place. You can also cut off one end of an extension cord and wire it to the back of a regular house outlet installed somewhere in your van. Some inverters also offer the ability to hardwire into them rather than using the three-prong outlets. Hope this helps, and best of luck with your build!
~John
Thank you so much for the peace of mind on this John!
Hi John, I’ve been off-grid for about 4 years. Mostly living and traveling on my 27′ sailboat. I’ve sailed 2 oceans and when on land have lived in an extended camping scenario out of my truck. It takes extreme lifestyle changes, especially in power consumption to do this effectively. I don’t have the luxury of chassis ground on the boat so all connections must lead back to the battery bank. This has lead to overcharge conditions during peak season sunlight hours that can vaporize LED lights. This is is despite having a mppt controller inline. Have you considered a voltage… Read more »
Hi Brian, sounds like quite the adventure. We’ve talked about trying out boat life one day. We have not considered a voltage regulator for the inverter. Most of our system runs off of DC, and we only turn on the inverter occasionally, when we run our hand blender or something like that. I hope the wind turbine works out, I’ve kicked that around as well.
Hey guys this breakdown helped so much but on you’re list of items under the inverter is the matching power switch for xantrex SP which I haven’t seen used throughout this walk through. Did you switch it out for the BEP switch?
Hi Brandi, you’re right, we don’t circle back to the inverter power switch in the walk through. The Xantrex power switch allows you to turn the inverter on/off remotely, so you can have your inverter tucked away somewhere. It plugs into the inverter with a basic data cable, then you can mount the switch where ever you like. It performs a different function than the BEP switch, which is a cut off switch for safety. Hope that clarifies!
John
Greetings, and thanks for providing so much information to do-it-yourselfers who need competent advice. I am looking at the Raver1800 Power Station to provide a portable solution to my van’s electrical needs. It is relatively new, but early reviews look good. My concern is whether the DC outputs can meet my needs. They advertise the following DC outputs: 4 x usb Ports 5V/3A, 1 x 12V/9A Port, and 1 x Type-C pd Port 45W. It seems that most of my wiring (lights, fan, water pump, refrigerator) would have to come from the single 9 Amp port. Is my assumption right,… Read more »
Hi Ole, it sounds like you are correct – you would have to wire your DC components to that 9A output. As far as whether that’s enough – that depends on your components. 12V refrigerators generally draw around 1A per hour on average, but it will draw more amperage whenever the compressor kicks on. It would be a useful exercise to look at the specs for all your components and add up the amp draws. If you can only find wattage, you can get the amps by diving watts by the voltage (12V). So if something draws 12W, you divide… Read more »
Hi there! I bought nearly the same batteries you use in your setup. Did you create some sort of way to ventilate the batteries? I’ve heard of it being necessary to ventilate them. And how exactly did you feed the solar panel wires into your van?
Thank you for sharing your process!
Hi Jasmine, we do have our batteries in a plywood battery box that we built, with vent holes drilled into it. These batteries are sealed so they technically don’t need ventilation. But they do have relief valves for venting gas if the batteries are overcharged (this should not happen often, if at all), so I wouldn’t put them in a fully sealed container. Regular lead acid batteries off gas all the time, and do need ventilaion, buut AGM batteries do not. Hope that helps!
One more question! I noticed in the comments that you recommended using a negative bus bar to ground all your components. Would you recommend a positive bus bar as well? I’m using one, and I feel it might have been a mistake. It has 4 posts, and I have the solar charge controller, inverter, and DC-DC charger running to it, with a single positive cable running up to the battery. Thoughts?
Hi Tim, I think bus bars are a great way to go, assuming you are using a bus bar and battery cable that are rated for the amperage running through them. The last electrical install I did we used heavy duty bus bars to attach all the components, then just connected the bus bars to the battery. It’s a whole lot easier to have several posts to work with, vs just the one battery post. We didn’t use bus bars to connect to the batteries in our van, so every time we want to add or remove or modify our… Read more »
Hi John! I was re-reading this post and noticed that you mentioned to NOT disconnect the aux battery when the panels are hooked to the charge controller. I didn’t know this, and disconnected the battery when I swapped my isolator for a DC-DC charger. I now notice that my panels don’t register much ah, even when they are in decent sunlight. Did I damage my system? What could be the issue?
Hi John, I could not have built my magic mobile without you! I have one question. I have 4x100w panels mounted in series-parallel and a 40A mppt hooked up to a 100A smart battery, all from Renogy. They are all connected through 8 AWG wire with the wire provided by renogy for the panels (I used the 8awg to connect the 12v load as well). I fused my mppt with a 40 anl fuse to the battery but I have not installed an in-line fuse to the panels. However, I was assured by renogy that both the cable and the… Read more »
Hi Max, thanks for the comment! What Renogy says may be true, but it’s still a good safety measure to fuse the panels in case of a short or other malfunction causing an overcurrent.
Assuming you’re using short wire runs and fusing properly, 2 AWG should be fine. We used 2 AWG for battery/inverter wiring in our van, and just made sure to fuse everything at 100A.
Hope that helps, and best of luck with the build!
~John
I’m trying to fimd out what size mppt charge controller do you use for that size of a system?
Hi Whitney, we used the 40A MPPT controller in our 400W system. Hope that helps!
Hey, Great post, super cool what you two have done! I have a question. I have a similar Van- 96 Starcraft conversion- and I cannot find the fuse box for the Conversion parts anywhere (TV, mood lights etc). The ones for the engine and general car workings are pretty easy to find so I am not sure if there is one as I have looked everywhere. Did you come across the original one on yours when you ripped all the wiring out? Thanks for reading great work!
Hi Blair, in our van the fusebox for all the conversion stuff was down under the steering wheel to the left of the driver’s feet (behind a plastic covering). Since your conversion was done by a different company, this may be different in your van. Hope that helps!
~John
Ho John, very helpful info here. At the beginning of the article you listed the battery isolator as an important component to have. Where does the isolator fit into the diagram? My guess would be between the batteries and the charge controller? My current set-up in the van I bought is an auxiliary battery onboard and a starter battery under to hood. They are both currently charged by either the alternator or by a battery charger when plugged in to shore power. We would like to add solar to the set-up to be able to spend more time off grid.… Read more »
Hi Bryant, the isolator actually goes in between the starter battery and the aux battery – i.e. starter battery positive terminal –> isolator –> aux battery positive terminal (with fuses in between). It sounds like you may have you batteries wired up in a similar fashion already. As far as incorporating solar, there’s nothing special you need to do – just hook your charge controller up to the aux battery and you’re good to go. Hope that helps!
~John
What size fuses do you use between the start bat and isolator and the isolator and the aux battery.
I also plan to use a cutoff switch.
Hello, your isolator or DC-DC charger should include fusing guidelines. With our Keyline Chargers isolator, we used a 100A fuse per the instructions on the starter side. However, on the end connected to your aux battery it would be a good idea to fuse based on your battery guidelines (our battery required a 40A fuse). Hope that helps!
John
Awesome post! You have explained it very well. Thanks for all the tips!! This will help immensely.
So glad this was helpful! Cheers!
Hi there, fantastic post.
My question:
Do I need to place the fuse box between the charge controller and the battery system?
You say you run 8 AWG positive wire from charge controller to the fuse box, I thought you hook the fuse box up from the battery?
Also, from the fuse box you run your 12V wiring system out to your 12V appliances?
Hi Kyle, thanks for reaching out. With Renogy systems, the fuse block for all your 12V components is separately attached to the charge controller. The fuse block is not in between the CC and the battery, the CC has separate ports for hooking up your 12V fuse block. If you choose, you could attach the fuse block directly to the battery instead, but you would lose out on some of the metering functionality provided by the CC. And yes, you would attach all your 12V appliances to the 12V fuse block. I hope that helps!
~John
Hi John, very informative article! I read through it all and a handful of the comments. I’m not very knowledgeable on electricity and it’s a bit of a confusing subject for me. Would the Highest Budget option be best if I wanted to run a fridge, microwave, fan (possibly a roof AC) and maybe a space heater in the winter (if needed). Everything would be running at once, but at times I could see 2-3 things going at once depending on the weather. Also when the van is running is it possible to charge the battery bank, or is everything… Read more »
Hi Luke, the roof AC and the space heater will both draw significant power, and might be tough even with the high budget option we outline (especially in winter, when you will be getting less sun). The best way to tell is to do some calculations. First, list the components you want to run along with the number of hours per day they will be running. Then, find the wattage of each component and multiply by the number of hours (i.e. a 1200W microwave run for 6 minutes each day = 120Wh; a 2000W heater run for 1 hour =… Read more »
Thanks for this informative article. I’ve learned a lot.
How can I ground one 100Ah battery if I can’t reach my vehicle’s chassis? Is grounding the battery required?
Hi Sarah, if you can’t reach the chassis, you can can ground all of your components (battery, inverter, etc) to a common bus bar instead. If you can access a point on the chassis that would be preferable, but your system will still function if it’s grounded to a bus bar. Make sure to get a heavy duty bus bar rated for a high amperage. Hope that helps!
Hi guys, I have a question: how did you choose the 100amp fuse for the connection between your inverter and battery? I’m having trouble figuring out how to size the fuse for this part, and the inverter manual/company hasn’t been helpful here. I’ve tried researching online to no avail. My inverter size must be odd, because it isn’t included in any of the online charts. I’m so sorry if you’ve already answered this question; tried searching for the answer in your responses, but 319 comments is a LOT of comments ha! Im glad you can help so many people out… Read more »
Hi Emma, so sorry for the delay. The fuse size we chose was based on the wire size that we used to connect the inverter to the battery. We used 2AWG wire, which is rated for about 100A, so that’s the fuse size we used. Your fuse size should be based on the size of your wiring, and your wire size should be based on the amperage that’s going through it. There’s a multi-step process to figure this out: 1. Calculate the max amperage going through your wire. To get this, take the surge wattage of your inverter (the highest… Read more »
Hello great info couldnt have done it without this site!!! I have a question about my rover mttp charge controller. I went with 2 125 vmax agm batteries and the the 20 a rover charge controller. There is no info that i can find how to set this controller for an agm battery. I currently have it set to gel setting. I thought about using the (use) setting and customizing the Float and boost voltage. But i dont know what to do about the equlization setting that cant be turned off only voltage adjusted. WHAT SETTING DO YOU USEFORAGM BATTERIES… Read more »
Hi Caden, to set the battery type on a Rover charge controller, see the instructions on page 19 of the manual here: https://www.renogy.com/content/RNG-CTRL-RVR20/RVR203040-Manual.pdf
I hope this helps!
This is interesting. Thank you for this!
Hi Nigel, so glad it was interesting!
Hi there! We have a 400 w system (4 100s) and are curious about wiring in both series and parallel.. but i don’t see many people doing that.. is it not possible? or does it just not work very well? thanks!
Hi Alex, great question! I think it depends on your setup, but if you plan to mount 4x100W on your roof, then series-parallel is the way that I would wire it. You would essentially wire each set of two panels in series, then wire that together in parallel. This gives you the best of both worlds – the higher voltages of series wiring, plus the panel independence of parallel (i.e. if one panel is shaded, it doesn’t affect the performance of all four – just the one it’s in series with). Series parallel is not possible in some situations, which… Read more »
Thanks for this informative article. I’ve learned a lot.
So glad it was helpful!
Hi! Thanks so much for this guide, it’s been extremely helpful for me during my van conversion. I’m using the 125Ah VMAX battery that you recommend (with a 100W Renogy panel and a 20A Epever MPPT controller). Whenever the battery is charging I’m noticing a bubbling/fizzing sound coming from inside the battery. I tried a new battery but the same thing is happening.. can you tell me if you ever hear similar noises from yours? Is it normal? (The internet seems to have very conflicting opinions about whether AGM batteries should be making noise..it’s really hard to know what is… Read more »
Hi! I bought the VMAX batteries (125Ah) that you recommend above, to use with a 100W Renogy panel and 20A MPPT charger controller. I have noticed that they make a bubbling/hissing sound as they are charging. Is this normal? Do your batteries do this as well?
Hi Jasmine, our batteries do not make noise when charging, and I don’t think they should be bubbling/hissing. I would contact VMAX customer support. Hope that helps!
~John
First of all, thanks a lot for this great blog that I have been using a lot recently . We are just camping warriors and I have decided on a battery isolator and an AGM deep cycle 100 Amp as our electrical needs are very limited (powering the fan mostly for now). I have read that these batteries should be used at less than 50% of their capacity, so how can I tell ? do I need a charge controller despite the fact that (for now) we don’t have solar panel ? Or can I use another device (I don’t… Read more »
Hi Nancy, I’m so glad our site has been helpful! You are correct that it’s generally not a good idea to deplete AGM or other lead acid batteries below 50%. The easiest way to tell would be check the voltage using a voltmeter/multimeter, or by installing a battery meter like this one. These devices will tell you your battery voltage, which is a fairly easy way to see where your batteries are. In DC systems, nominal voltage (12V in a 12V system) is approximately 50% charged. So, you can just keep an eye on the battery voltage and make sure… Read more »
Hi John,
I’m curious, are the outlets you ran from your fuse box for AC appliances? If so, why did you decide to do that instead of running outlets from an inverter? I know you have a power strip coming from the inverter, but I’m curious as to why/ how it works to have outlets coming from DC power/ the fuse box. Seems like others have their outlets coming from their inverter so it’s AC power.
Thanks for the article, it’s a great research and I’ve learned a lot from it.
Sam
Hi Sam, the outlets you speak of are all 12V outlets. Our entire van runs off of 12V DC, including our lights, fan, and fridge. The 12V outlets are cigarette lighter style, and we plug in USB or USB-C charging units for charging phones, speakers, headlamps, lanterns, and anything else with a USB or USB-C connector. We originally included a mixture of 12V USB outlets as well, but these did not output enough amperage to keep up with today’s quick-charge technology, and also constantly emitted an annoying blue LED light. Having 12V cigarette lighter plugs allows us to switch out… Read more »
OK, that’s makes sense. Thanks for the clarification.
I can’t wrap my head around why the fuse between the battery and the inverter is so large. Even if the inverter is rated for it, wouldn’t I have to be doing something terribly wrong to draw 100 amps off the battery? That’s like 3 table saws, a toaster oven, and a washing machine xD. Or am I missing something between the conversion of DC to AC?
Thank you so much for this valuable resource – it’s been great for planning out my solar.
Hi Cam, the fuse sizing is generally based on the wire gauge to prevent the wire from overheating. While it definitely may take a lot of devices to draw 100A continuously, I believe the thick wire gauges and corresponding fuses are more to accommodate surges. A blender, for example, is going to have a startup surge that briefly draws more power than it does when it’s just running. If you go with a fuse that’s too small, you may risk popping the fuse with startup surges. Hope that helps!
~John
This is all so intimidating! We are on a barebones budget and wondering if we absolutely need solar panels if we are going to have a vent fan. Thank you for any insight!
Hi Whitney, you definitely don’t need solar for a barebones electrical setup, but you do need to make sure you have enough battery capacity for the things that you’re running, as well as a means to charge up your batteries, such as a battery isolator. The typical vent fan draws between 1A (on low) and 3A (on high), per hour that it’s running, so it can be a fairly significant load if you’re keeping it on all the time. If your means of charging is a battery isolator, that means you’ll need to drive your van in order to charge… Read more »
Hey, great post! Do you think a normal Voltmeter is enough to monitor the charge of the batterie? Where would I wire it in? Directly to the batterie?
Cheers
Paul
Hi Paul, a normal voltmeter should work just fine, since the voltage is really all you need to keep an eye on. You would wire it directly to the batteries, or you can buy inexpensive battery meters on Amazon that include a shunt. Hope that helps!
Hey, quick question as I’m currently copying and pasting this set up into my DIY skoolie.
When you ground the batteries to the chassis, do you ground each of them separately or does one connection do the job? Thanks in advance.
Hi Allyson, assuming your batteries are wired together one connection takes care of the grounding for both. Hope that helps!
~John
John, thanks for all of the info. Im looking to do the more budget option, without any solar. Ive been working on an astro van, and looking to do some camping, but not really the full van life experience. Im hoping to setup a secondary battery with an isolator to power the car stereo and basic original electronics, including lights and 12v outlets, in the vehicle when the engine is off, but Im getting mixed information about whether or not I can do this. I think what you and many other people are doing is creating an electrical system entirely… Read more »
Hi Mike, thanks for reaching out! In order to do what you’re talking about, you would need to change the wiring for the stereo, lights, etc, so that they are being powered by your secondary battery instead of the main vehicle battery. One way to do this would be to reroute the wiring. There should be a fuse box somewhere (under the hood, under one of the seats, or down by the driver’s door are all places to look) where all of these components connect. If you figure out which fuses are for the stereo, lights, etc, you can then… Read more »
Hiya! Thanks so much for the awesome post, its been such a huge help. Question on the placement of your battery on/off switches. If your not supposed to have your panels hooked up to the charge controller without also being hooked up to the battery, why put an on/off switch between the battery and charge controller? Wouldn’t that possibly damage the system if you shut it off?
Hi Andy, great question. Yes, you would not want to shut off that switch without first disconnecting the solar panels. We did this in order to be able to shut of the load in case we had to work on the system. But we’ve since rearranged things so we no longer have this cutoff switch. We are working on a full update of this post and the wiring diagrams currently. Hope that helps!
~John
Hi, Thank you for the entire article and for making sense of wiring a solar system to a van. I am in the process of buying a van. I am looking at a Ram Promaster 2500. how many solar panels can I fit on the roof of that van? and do you wire the ceiling fan into the solar system or into the vans own electrical unit?
Hi Jamie, thanks for reaching out! That depends on the wheelbase you get (i.e. the length of your Promaster), but if you want to max out your solar you should be able to fit at least 6-8 panels (600W – 800W) on the roof. Keep in mind that you will also want space available to install a ceiling vent fan. You may be able to fit more up there depending on how you arrange them, but it’s generally a good exercise to size your system based on how much electricity you plan on using, since costs can quickly escalate with… Read more »
Hey guys! Firstly, wanted to say thanks for this whole site! It’s helped me a ton and I made sure to buy everything I needed from you links :). I was curious if you had any tips for installing the isolator? I just got one and my solar is basically the exact same you have but with 2 100-watt panels and one single battery. ( just traveling here and there, not living.) any suggestions?
Hi Trevor, thanks of reaching out, and thanks for the support :-)! We go over how we installed our isolator here: https://gnomadhome.com/vanlife-installing-battery-isolator/ We need to update this post, so here are a few additional tips: –I highly recommend fusing at both ends (by the starting battery and by the aux battery) –Instead of just running the bare wire under your vehicle, run it through some wire sheathing first. This will help prevent abrasion on the wire and potentially cutting through the insulation, which will cause your fuses to blow. Hope that helps! Let me know if you have other questions!… Read more »
Hi! Awesome and informative post!! I have one question. Im not sure should I use 40A, 30A or smaller fuse between solar panel and CC. I have 285w 24V solar panel and 30A CC. My battery is 12v 220ah AGM. Thanks a lot!!
Hi Lii, your charge controller should have fusing guidelines, but in general you want to use a fuse that matches the amperage of your charge controller (i.e. 30A for a 30A charge controller). Hope that helps!
~John
Awesome guide guys! Any update on installing permanent AC wall outlets? I have pretty much the exact same electrical system as you guys but am currently trying to wire outlets and having some difficulties. I will keep researching but would love to hear if you’ve had any success since our systems are so similar. Thanks!
Hi Josh, thanks for the kind words! Installing permanent wall outlets involves wiring the outlets to your inverter. There are two ways you could do this: 1. Purchase an inverter that has direct wiring outputs (meaning terminals to connect positive/negative/ground wires for directly wiring to an outlet). Your typical RV/campervan inverter generally only has typical 3-pronged outlets as the ouputs, and does not include direct wiring terminals. However, it is possible to find these if you go looking on Amazon, including from reputable companies like Samlex and AIMS. 2. If your inverter only has 3-prong outlets for the output, you… Read more »
Thanks for all the info, in ONE place! I’m just beginning to put together an electrical system in my 1997 Chevrolet Express 1500, and trying to figure out what in the devil I’ve gotten myself into was getting confusing and disheartening. Thanks, again!!!
Hi Deb, so glad we could help! Best of luck!
~John
It’s so much easier to refer to your page, and put it all together. I’ve gotten the isolator installed, the cable running underneath to the passenger side running board, then up through the grommet into the van with no need to drill into the floor. Waiting for a battery box to put the batteries into and then set up in front and under the backseat/bed. Not doing solar yet, but it’ll be a snap after all of this. Much thanks to all of the instructions and pictures/videos that y’all were kind enough to share!!!
Hi Deb, so glad that we could be helpful! Best of luck with your journey!
~John
I’m using a renogy 300w panel (and controller) with four lithium-iron phosphate batteries. I bought used from someone, and was only using a 80cu Dometic fridge, so I waited for the batteries to drain before installing the panel (I actually have 900W, but that seemed like overkill for what I needed, so I only put 300 on the van). It took about two weeks for the batteries to deplete, then I installed the panel. Perhaps it was a mistake to fully discharge the batteries, but now I feel like once I finally got the batteries charged again (with the solar… Read more »
Hi James, so sorry for the delay in responding to this! So do you have 400ah of batteries? It’s definitely hard to imagine a Dometic fridge depleting that large of a LiFePO battery bank that quickly, but our system definitely drains down in a few days of overcast weather. Are you running other loads like a vent fan, etc? I hope things are working better for you now!
~John
How much did it cost in total?
Hi Syd, our entire electrical system cost us right about $2,000. This included solar, batteries, inverter, isolator, and all wiring, fuses, and other components. This same setup would probably cost slightly less today, since some of the components are a bit cheaper than they were three years ago. You can see a further breakdown of our build costs here: https://gnomadhome.com/our-rig/
Hope that helps!
~John
Thanks for sharing. I found a lot of interesting information here. A really good post, very thankful and hopeful that you will write many more posts like this one.
Hi there,
So, I bought the exact same solar and battery setup as you guys and I am curious to know what you have set for Charged Voltage on your Battery Monitor and/or Charge Controller. For example, say you are entering your van about an hour after the sun has set, what voltage would your battery monitor read at that time? Please let me know. Thank you so much for your time and effort with putting the website and how-to’s together, I know the vanlife community greatly appreciates it.
Best,
Andrew
Hi Andrew, thanks for commenting and thanks so much for the kind words! When our batteries are fully charged and no longer taking in energy from the sun, I would expect the voltage to be in the neighborhood of 12.8-12.9. Nominal voltage (i.e. 12.0 in a 12V system) is about 50% charge, and you will want to stay above that (assuming you have lead acid or AGM batteries). Going below 12.0 too frequently will effect the longevity of your batteries. Hope that helps!
~John
Greetings, I can’t thank you enough for wealth of info and experience from your guides and articles. One question about sizing… I believe that you mentioned a good rule is to match the solar to the batt capacity. In your system you have 400 w of solar power and (I believe two 155ah batteries) for 310ah. So you have more solar than your batt capacity – ok makes sense to me. But what about budget and future builds… If I can afford 200 w of solar power (two panels) I was thinking of getting the two 155ah batteries for the… Read more »
Hi Brian, thanks for reaching out! We actually only have 300W of solar permanently mounted on our van. The other 100W panel we keep stored in the trunk for additional as-needed capacity. With 300W of solar and 310ah of batteries, we are usually able to fully charge each day, but if we have several days of overcast weather or are spending time in the woods (where there isn’t always full sun), we can run into charging issues, even with our fourth panel, so I would say that 200W of solar alone would have a tough time keeping up if you’re… Read more »
Hi John! Thank you so much for creating this great resource. Your website has kept us sane on our van build journey the last few months! I have a couple of questions for you on determining wire sizes. I am a novice when it comes to anything electrical related and am having a hard time wrapping my head around some of it. We have purchased the same lights that you have in your van, but we plan on wiring them in series. When determining the wire length for the calculation, should I be using the length from the light switch… Read more »
Hi Lindsay, so glad our resources have been helpful! For calculating the wire length, you will want to use the total length of the wiring in the circuit – so, from the light switch to the lights (and in between the lights) and back. For the load current, you will want to calculate the max amperage of all the lights in the circuit combined. For example, those LED lights are 3W each on full blast. 3W x 4 lights = 12W total. To calculate the amperage, divide the wattage by the voltage of your system. Assuming you’re running a 12V… Read more »
Hey, I couldn’t find on your blog what determines wire size between charge controller and fuse board. Would it be the total load on fuse board or the charge controller size.
Hi Will, there are a few factors in play here: 1. The total load on the fuse block. You always want to make sure that your wiring can handle any potential loads that might go through it. 2. The load capacity of the charge controller. For example, Renogy charge controllers can only handle 20A of continuous load (even the 40A ones – the amperage rating refers to charging amperage, not load amperage). Even if you have more than 20A on your fuse block, you’re probably not going to run everything at once, so this may not be an issue (you… Read more »
Why did you decide to go with the inverter charger rather than the converter charger. Thanks
Hi Ervin, thanks for reaching out! We actually just have a regular ol’ inverter without any charging ability. But, I certainly would recommend an inverter/charger over a converter/charger in most cases. All the converter/charger does is convert the 120V AC electricity from plugging in at a campground to 12V DC so that it can charge the batteries. With this setup, you can only use 120V AC while you’re plugged into shore power (unless you also get a separate inverter) This could be a fine option if you’re always going to be plugged in. An inverter/charger, on the other hand charges… Read more »
Awesome work guys! Made things so much easier for me.. I am currently planning my own first van build
Thank you so much !
😀
Glad we could help, Dan! 🙂 Best of luck with the build!
This is the best article on the subject that I have seen! Stressed newbie here. Question: how do you use a larger wire when your charge controller only accepts a 8 AWG? Like if you want to use a larger wire out to the solar panels?
Hi Teri, so glad you found this article helpful! There shouldn’t be any need to use a larger gauge wire than your charge controller can fit. 8 AWG wire can handle at least 40A of current (https://www.cerrowire.com/products/resources/tables-calculators/ampacity-charts), which is the maximum input current for a 40A charge controller. Since you won’t be inputting more that 40A of current, there’s no real need to go larger than 8 AWG. Hope that helps!
~John
Hi – How are you? Thanks for all the great info – I have a question – your simple wire diagram shows a shut off switch between the solar panel charge controller and the house batteries. This would allow you to disconnect the batteries while the charge controller is still connected to the panels. This is a big No No. Shouldn’t there be a switch between the panels and charge controller instead or in additon? Thanks. Steve
Hi Steve, disconnecting the batteries while the solar panels are still attached is absolutely a big no-no, as we mention in the post. We usually just disconnect the positive wire from the solar panels to the charge controller first, but adding an additional cut off switch is a good idea. We are planning on updating this diagram in the future to reduce any confusion on this point. Thanks for the input!
~John