How to Build the Best Overland Battery Setup
There’s nothing like the thrill of leaving the pavement behind and exploring the wild while still enjoying the comforts of your overland rig. But while overlanding may be a thrill, dealing with the rig’s power system isn’t most people’s idea of a good time. However, the right overland battery setup can be a game-changer for your next adventure. Let’s take a closer look at how it all works and how to pick the best overland battery.
Table of contents
- Easy to Charge
- Charge With Your Alternator
- Use Solar Power
- Run a Dual Battery System
- Combine Solar With Another Method
Overlanding may be a chance to rough it and get out in the wild, but that doesn’t mean you need to give up some of the comforts of home and the necessary systems for getting you where you’re going. However, out in the backcountry, you won’t find any outlets or shore power to keep things charged. That’s why batteries are such a crucial part of any overland setup.
In addition to powering necessary things like the engine, headlights, and radios, batteries need to provide electricity for camping. Overlanders can accomplish this either with one battery bank shared between these two uses, or a dual battery bank setup.
Dual battery setups use one battery for vehicle uses (a “starter battery”) and a completely separate one for things that make you feel at home (a “house battery”). The dual setup is preferred as the engine battery requirements are very different from the “house” or camping requirements.
Do You Need a Dual Battery Setup for Overlanding?
Some people get by with an overland battery setup with just a single battery. But all too often this can lead to a dead battery, potentially stranding explorers in an uncomfortable or even dangerous situation. While it may not be strictly necessary, a dual battery setup is without a doubt the gold standard for overlanding power.
We’ve already mentioned the ability to power different portions of an overlanding rig’s electrical needs through different batteries. This provides many more options for accessories and other systems using their own dedicated power.
Dual battery setups also offer the distinct advantage of allowing overlanders to use their camping batteries without worry of not being able to start the engine, providing an additional level of protection. In addition, the second battery bank can even act as a self jump starter. This is accomplished by wiring the two batteries in parallel through a relay or isolator.
Another reason a dual battery setup is recommended is that the engine starting battery has a very different job than the house batteries. Starting an engine requires an enormous amount of power for a very short period of time, after which the engine immediately recharges the battery.
House batteries need much less power but to run for a long time and discharge the battery deeply. For this reason, lithium batteries, like our Battle Born Batteries, are best for house or camping batteries and a lead-acid or AGM is best for starting.
Best of all, the downsides are minimal to a dual battery setup. Among the only negatives of a dual battery setup is the cost. Overlanders will need to purchase an extra battery as well as the isolator technology. In addition, they’ll need to pay for a professional to modify their electrical setup if they’re not comfortable doing these upgrades on their own. All of this can impede overlanders looking to explore on a tight budget.
Background. Why Has It Taken Three Years?
There are really two types of vehicle adventuring in my book. One. where the vehicle is driven most of the day, only really stopping at night to camp. allows the alternator to keep the battery(s) charged. The other. where the vehicle is driven to a given location, and then not started for several days while that location is enjoyed. means that some other method must be used to keep batteries charged and electronics running.
Neither style of camping is best, but each has their own set of considerations.
For the last several years. and even today. the first style of adventure is my primary mode of getting out there. I can count on my fingers the number of nights that I’ve stayed in the same spot more than once, so using the alternator to keep everything going has been great. Sure, at some point I wanted a bit of redundancy and added a secondary battery to my setup to give me peace of mind on hot summer nights. but mostly I did that so that I could be confident about starting the truck in some of the remote locations we visit.
But, for three years now I’ve been going on at least one or two trips each year where I stay in one spot for an extended time. Usually these are family trips. with @mini and @mrs.turbodb, or with my Dad. where the goal is enjoying each other’s company more than it is seeing everything we can. And, as hiking becomes a bigger part of each adventure, even the see everything trips can often mean the Tacoma sits for a day while we explore on foot.
Before the fridge, this wouldn’t have been much of an issue. I could still go back to a cooler with ice for these types of adventures. But the fridge is one of the top three game-changing mods from my perspective and makes life so much easier that it was time to find a solution that allowed it to keep doing its job.
What I Choose and Why
My requirements when I started were relatively simple, I thought:
- Have enough power to keep the fridge running at 37ºF during the a 90ºF day (and night).
- Be able to move the system between the Tacoma and 4Runner, since family-basecamp-style camping happens in both vehicles.
The Panel Itself
Initially, I thought I was going to get a rigid panel that I could mount to the roof of the Tacoma. over the sunroof, which I dislike because the sun shining through all day makes me hot. and solve two issues with one solution. Quick releases would mean that I could move the panel between vehicles, or not bring it at all on trips where I knew I’d be driving all the time.
Nice conceptually, but not ideal in practice. Form over function, really.
But, after a bit more research, there were a couple drawbacks that I just couldn’t get over: first, rigid panels are relatively heavy at between 20-30lbs. Second, by mounting the panel flat on the roof, I’d be limiting my ability to orient it towards the sun, and I’d require myself to park in the sun rather than leaving the panel in the sun and parking the truck (and fridge) in the shade.
So, I started considering a rigid panel that folded. This wouldn’t solve the weight issue, but would allow me to position the solar panels away from the vehicle and orient them toward the sun for maximum power generation. Still, these are big an bulky and I didn’t like the idea of having to pack them in the cab.
Fully functional, but clumsy form in that the panels would be hard to pack around. And still heavy.
I kept looking, and eventually stumbled upon a few informative online articles and videos that talked about solar blankets. These are less blankets and more small panels hooked together with flexible material. As such, some can fold up into reasonably small packages, and they weigh significantly less than rigid panels since there’s no aluminum frame, glass on the panel, backing plate, mounting hardware, etc. The only problem. predictably. is that they can be costly. This Off-Grid-Trek was recently featured on Expedition Portal, but their cheapest 200W blankets cost nearly (cough) 1500; a 112W REDARC offering costs over 1700 at the time of writing and is not even sold in the USA.
But then, with some more research, I stumbled upon a reasonably cheap foldable panel that seemed to tick all my boxes. The TP-solar 100W Foldable Solar Panel Charger Kit.
- Rated for 100W of power (though no panel ever reaches this rating. 60%-70% is the best you can hope for).
- Folded into 11x8x3 (basically the size of a ream of printer paper) for transport.
- Weighed only 5 lbs.
- Could easily be positioned away from the vehicle (with a custom cable).
- Was completely standalone and could move between vehicles.
- Was reasonably inexpensive.
And, it (initially) seemed to tick a few more as well:
- Came with a charge controller that would charge USB devices directly, and 12V car batteries with a supplied adapter.
- Came with a bunch of adapters for various 12-24V devices (laptops, etc.).
- Great reviews from folks who’d purchased it before me!
The Charge Controller
There was however, one drawback to the panel/charge controller kit that I’d found: the charge controller was meh at best, for two reasons:
- It was a PWM controller. on this below.
- When charging the car battery, rather than use the 19V/5A plug on the charge controller, the instructions directed me to use an adapter that stepped up the USB voltage to 13.8V and a maximum of 2A. for a max charge of ~27W, less than 1/3 of what the panel could generate through the 19V/5A port.
The first issue I could live with. after all, what I really cared about was charging, not the technology used for that charge. The second issue though was a showstopper for me; with a 100W panel, I knew I needed to get as much power as I could out of the panel if I hoped to keep the batteries charged and the fridge running on hot days in camp. So I started looking at charge controllers.
Initially, I thought I’d get a REDARC BCDC1225D DC-DC Charger w/Solar. I’ve heard great things about Redarc, and knew it’d work just fine for my purposes. But, I also knew it was overkill. after all, a big part. the main part really. of the Redarc DC charger is to keep a second battery charged from the alternator, with solar being a secondary consideration. Plus, it cost nearly 400, bleh!
So I started doing more research. I quickly discovered that there are two types of solar controllers that exist today (2020):
Setting It All Up Was Easy
Most of my time on this project was spent in the research phase. so here’s a quick review of the parts I ended up with. Total cost of these parts was under 400.
- Solar panel. TP-solar 100W Foldable Solar Panel Charger Kit.
- Charge controller. Victron SmartSolar MPPT 100/20 Solar Charge Controller w/Bluetooth
- Supplies to make extension cable to locate panel up to 30′ away from vehicle:
- DC Connector Male 2.1mm 5.5mm. plugs into the 19V/5A plug on the solar panel, for the extension cable to the charge controller.
- 30A Anderson Powerpole connectors (10 pair). used to connect the charge controller to the battery, as well as for the extension cable from the panel.
- 30 feet of 12ga red and black wire
- 30 feet of 1/2 inch braided wire sleeve
- some heat shrink tubing in various sizes
With everything in hand, I set about installing the components. This install will be specific to each vehicle, but entails essentially two parts: first, connecting the controller to the battery and second, connecting the solar panel to the controller. The only thing that’s important in these connections is that the connection between the controller and battery is made prior to the connection between the controller and solar panel, and that when disconnecting, the opposite order is observed.
In the simplest system, the charge controller could be constantly connected to the battery. This would meet the connection order criteria, but has the drawback that the charge controller draws a bit of power from the battery at all times (to enable Bluetooth, and the internals of the controller). As such, a better solution is to place a quick connect between the controller and battery. either using something like an Anderson Powerpole connector or even a Bussmann 80A Circuit Breaker. The Anderson connectors are both simpler and cheaper, so I opted for this route, making two short lengths of 12ga red/black wire. One end of both these wire sets connected to the controller and battery respectively, and the other end terminated in an Anderson connector. allowing the two components to be quickly dis/connected.
I also mounted the charge controller vertically. as per the installation instructions. in the electronics drawer of my in-cab power distribution station.
The only other step was to create a 30′ long, 12ga red/black cable that would connect the charge controller to the solar panel. I started by measuring out two lengths of red and black cable and fishing them through a similar length of wire loom in order to keep them tidy. A bit of shrink wrap on each end completed the bundle. Then, one end of the cable received a Male 2.1×5.5mm connector that would plug into the solar panel, and the other end received a pair of powerpole connector that I could plug into a small 12ga pigtail running out of the controller.
Note: I was asked a good question about the connectors that I’ve linked, since they have a 16ga pigtail, and the rest of my extension cable is 12ga. Does that reduction in wire size cause any sort of problem? Check out my response in the Комментарии и мнения владельцев below.
So, How’s It Work?
The short answer is: better than I could have ever imagined. The first few days I used it, I kept mentioning to @mrs.turbodb how magical it all was!
The solar panel can be positioned in the most convenient location. on the roof, windshield, next to the vehicle. wherever the most power is generated.
And, both the panel and controller seem to work spectacularly. Peak power appears to be on the order of 70W out of the panel. right at the theoretical maximum I’d expect, and the controller does a splendid job of managing that power into the batteries over time.
A few very interesting things I’ve noticed over the first week or so of daily use:
- Using this system in conjunction with the Blue Sea ML-ACR works wonderfully. Leaving the ML-ACR in auto mode, if the batteries have disconnected for any reason, the solar system first begins charging the house battery. to which it is directly connected. and then after a period of time the ML-ACR links the batteries and the solar system charges both batteries as a bank.
- The Victron SmartSolar controller does a great job of charging AGM batteries. It varies the voltage into the battery based on the current battery voltage, meaning the battery is optimally charged to its full capacity.
- A 100W panel in full sun on a 90ºF day is more than enough to keep both batteries completely charged. even with the fridge running at 37ºF, a laptop charging, and other devices (camera batteries, phones) charging as well.
- The key to solar is that devices such as the fridge and laptop charge over a limited period of time. During this time, battery voltage may drop (a relatively small bit), but as soon as they are done drawing power, the battery is fully replenished (quickly) by the solar system.
As of now, I couldn’t be happier. Adding solar has enabled me to camp-in-place much more confidently than I have in the past. Well, the recent past anyway, with food cooled in the fridge!
Hard mounted panels come with their own set of pros and cons, which are really just the opposite of the suitcase style setups. Since they are physically attached to your vehicle or trailer, they can’t be placed out in the sun and rotated if you park in the shade. This means that even if you park in the sun, they are not going to be pointed in the optimum position for a good portion of the day. This is offset to a large degree (and maybe entirely depending on when you setup camp) by the fact that they will be producing power from the earliest rays of sun in the morning until the last rays of the evening. They will also be charging for hours on end while you are driving during the day. The risk of someone walking away with them is also greatly reduced while you are out exploring, adding even more time that they can be charging over a suitcase setup.
In the end it really comes down to how you overland or camp. If you are a setup camp and hang out type of person, the suitcase style is probably your best bet. If you are an overlander where you travel from place to place a lot on a trip, then hard mounting is the way to go. For me, hard mounting was the way to go since I like to travel from place to place each day.
Hard Mounting 100 watts of solar on an OGT Expedition 2.0
Once I decided to hard mount the panels, the biggest issue to solve was were to actually mount them on my trailer. If you do not have a roof top tent on your trailer, there is plenty of space on the roof rack to mount all the solar panels that you might need. If you are like me and need to run a RTT at least some of the time, then your choices of locations is rather limited. You could mount a panel flat on top of the front box, but then you lose that storage space. You could also mount it on the front slope of the trailer where the front box is, but again you lose some of that storage space and anything you place in there will partially block the panels. You can mount a panel under the roof rack on a slide so that you can deploy it when you are setup at camp, but then you might as well be using a suitcase style setup. With all these things taken into account, I decide the best option for me was to mount two 50 watt panels on either side of the roof vent. Renogy makes some nice 50w panels that fit perfectly to either side of the standard roof vent. I’m not sure if the upgraded vent is wider, so if you have that option be sure to double check that there is enough room up there for the panels.
The one thing I did not like about these panels is that the frame is bare aluminum and the bright silver finish really stood out on top of the black roof. I solved this problem by spray painting the frames with black Plasti-dip. If you don’t know, aluminum does not take paint very well without a special primer being applied first. While there are some spray paints out there that will adhere to bare aluminum, they would probably not hold up well to offroad use over time. Plasti-dip is a thick, almost rubber like, paint substitute that forms a nonpermanent bond to whatever it is covering. It is a really unique product that can be easily removed when you want to, but otherwise withstands a lot of abuse without cracking, chipping or tearing. I’ve used it for years on the door hinges of my Jeep and it has held up very well to rocks hitting them and tree branches scraping against them.
The process of Plasti-dipping them is pretty easy. First cover the center of the solar panels with masking tape, leaving about 2 inches next to the frame uncovered.
You want the frame and the surrounding area to be completely covered in the Plasti-dip, but by covering the center you will use less Plasti-dip and make it easier to start peeling the excess material off. Take your time spraying it on in thin, even coats. You want about 5 or 6 coats total for good coverage and protection.
Once it has dried all the way, you can start peeling the unwanted Plasti-dip away from the solar panel. Using the masking tape helps get it started.
Once it starts to peel off, it will be like a thick film, pull it at an angle to the frame. The really cool thing about Plasti-dip is that it will tear off and conform to just about any change in surface height, wrapping around edges to give near perfect coverage and straight edges.
With the panel frames now blackened for a cleaner look, it is time to fab up the mounting hardware.
The method I chose was to use some aluminum angle and some T slot track I had laying around the shop. I cut the aluminum angle down to the length of the panels and then clamped it to the panel and the panel down to my work table. I could then drill four bolt holes through the aluminum angle and the panel frame and have them all lined up correctly.
Once the holes were drilled in the aluminum angle, I then powder coated them gloss black to match the trailer top. I could have also Plasti-dipped those as well, but since I had the ability to powder coat them, I did. My leftover T Slot was used on the inside of the panels frame to clamp the panel to the aluminum angle. The aluminum angle would then be attached to the top of the trailer with Very High Bond tape.
Running the Cables
With the panels mounted and the hole into the front box it was time to run the wiring. The connectors on the passenger side panel was ran out of the notches that I had cut and then plugged into a short 3′ section of solar cable. This was in turn was connected to the driver’s side panel via some Y connectors. The other end of those Y connectors was plugged into a 10′ section of solar cable and ran into the front box. All of the cabling was secured using zip tie mounts.
To keep the front box water proof, I used a cable entry gland where the cables entered. I also ensured that the cables had a “drip loop” in them before entering the gable gland.
Another drip loop was used inside to make sure no spilt liquids could run down into the Renogy 30a charge controller. I went with a 30a controller so I could add more panels in the future if I needed to.
Back to the future
As I mentioned above, I wanted to make sure that I could add in more solar panels in the future if needed. Since I did not use the OGT SAE port on the front box for my hard mounted panels, I can easily connect another panel or two, or even a suitcase style system, by using a MC4 to SAE adapter.
After installing these solar panels, there are a couple of things that I would do slightly different.
First I would have simplified my mounting system. There is no need to use the T Slots and they actually make things a little more difficult then it needs to be. I thought the ability of the bolts to slide would make it easier to align them with the holes in the panel frames. If I did it again, I would simply cut a notch in the aluminum angle and just bolt the frames directly to that. Tightening the nut on the bolt would be enough to clamp the panel to the aluminum angle. I might cut the notch at a 45° angle going towards the front of the trailer. That way if the nuts were to come lose going down the road, the wind would have to lift the panel up and move it forward (against the wind) before they could come lose from the mounts.
The second thing I would do is put some wire loom over the solar cables, just so they do not stand out so much on the trailer. I might still go back and do this as a winter project.
Truck Camper Solar Set Up
After a few years of Class B RV life, we switched to a pop-up truck camper mounted on a Ford F350 Super Duty truck. This RV had 320 watts of rooftop solar, 250 watts of portable solar and a 300-amp hour lithium battery system.
This was our first experience living out of an RV with rooftop solar panels and portable solar panels. Since the truck camper did not have A/C, the rooftop solar panels were more than adequate to keep the camper batteries charged.
When we parked the truck camper in the shade, we would deploy the Overland Solar portable solar panels to harness the sun’s energy.
For reference, here are a few of the items we ran on a daily basis (in addition to the vent fans and fridge):
- Electric coffee grinder – 165 watts
- Electric water kettle – 1,500 watts
- Electric multi-cooker – 1,000 watts
- Charge devices (laptops, cell phones, e-readers, backup batteries)
Current RV Solar Set Up
Our current RV is a Class B camper van by Storyteller Overland built on the Ford Transit chassis. This RV has 90 watts of rooftop solar, 260 watts of portable solar and a 1000-amp hour lithium battery system.
This RV has the most robust energy setup we have experienced so far. The idea behind the large battery bank is to use the vehicle’s secondary alternator to recharge the battery bank while driving. Using this method, we can be stationary four to five days before we have to break camp and drive around or idle the engine on high to recharge the batteries.
When we prefer to camp longer, we have two Overland Solar portable solar panels for a total of 260 watts. These, coupled with the 90 watts rooftop solar panel is enough to double the amount of time we can stay camped in one spot before having to break camp and drive around to charge the batteries.
Our experiences with different RV solar set ups has taught us that rooftop solar panels and portable solar panels can complement each other well, each one compensating for the other’s shortcomings. Both have their pros and cons, and the best choice depends on various factors, such as your RV’s power needs and budget.
For instance, with our Class A motorhome’s small battery bank, it didn’t make sense to invest heavily in an RV solar system without also upgrading the RV’s batteries. So, if you’re considering a solar setup for your RV, it’s essential to understand your power needs and limitations and to look at your camper’s electrical system as a whole. Consulting professionals can also provide you with valuable insights to help make the most suitable choice for your situation.
Remember, an efficient solar system is not just about the solar panels; it’s also about the batteries, your energy consumption, and your RV lifestyle. And when these aspects are harmoniously combined, you can significantly enhance your RV experience.
Thank you for reading! I hope you found this comparison of portable solar panels vs rooftop solar panels helpful. If you have experience with either or both, please fee free to share by leaving a comment below or on the video.