How to Create the Best Camping Battery 12v Setup

Posted By: Superior Staff Published: 14/04/2025 Times Read: 452 Comments: 0

There’s no doubt about it, getting your 12V set-up dialled in is one of the most useful additions you can make to your 4wd and camping setup. Nothing beats having the fridge humming away, the LED lighting creating the perfect amount of ambience and these days, you can even bring things like a coffee machine or microwave if you’re feeling classy.

However, it’s not all free beers and Barista made latte's, there is a ton of electrical knowledge required to get the most out of your 12V system, and there’s more gadgetry and technical wizardry on the market than ever before. So, if you’ve never wired a dual battery system up in your vehicle or are getting back into it after a few years (or decades), there’s a few things you need to be up to date on before starting.

Understanding 12V Systems for Camping <H2>

In its simplest form a 12V battery system is made up of 4 basic components. First is the battery, this can be AGM, Lithium, or Lead Acid; followed by a means of keeping that battery charged (a combination of DC-DC chargers and solar usually). Then comes mounting your componentry, and finally, a method of monitoring it all.

Sounds simple right? Yeah nah. Let’s break it down.

First you need to work out your current draw, this is how much power all your accessories will require to run when in use, in the industry this is typically mentioned as Amp Hours (AH). There are a bunch of calculators online to help you with this, but we will do a simple setup for an example. Say you want to power up a 60L fridge, some LED camp lights and maybe charge your Ecoxgear Bluetooth speaker.

We will focus on a 24-hour period. On average a fridge draws 3 AH, multiple camp lights can draw 5 AH; and the speaker charger draws 15amps. Now, while your fridge will be on for the entire 24hrs at camp, you won’t be constantly using the lights or charger, so we must factor in an hourly usage rate. Say you’ll use the lights for 3 hours once the sun dips below the horizon and the charger only needs an hour to top off your speaker. The lights’ daily current draw becomes 15A and the charger is 15A.

3 AH x 24 = 72 (Fridge)

5 AH x 3 = 15 (Camp Lights)

15 AH x 1 = 15 (Speaker Charger)

72+15+15 = 102 AH needed for a 24Hour Period.

In this case, a 150AH lithium (which can typically be drawn down to 80%) or a 210AH AGM (which can only be drawn down to ~50% of its capacity) will be up to the task of handling your camping without charge from any external source for a 24hr period. But something we will touch on soon is Solar which can allow for additional AH gained without moving your vehicle.

Choosing the Right Battery

Once you have your current draw mapped out, it’s time to select your battery. The cheapest option is a lead acid wet cell battery, which we only really suggest for those on a very tight budget. A little more spending will get you a better set-up, which can be lightweight and provide more usable Amp Hours.

This brings us to Absorbed Glass Mat (AGM) batteries, it uses a glass weave (similar to raw fibreglass matting) which is sandwiched in between the internal plates, this is designed to absorb the acid and lower the resistance. It enables faster charging and allows increased current delivery when required. These manage to land in a more affordable budget option, making it the second-best option available.

The latest and growingly popular option is the lithium (LiFePO4) batteries. They charge faster, last longer, weigh less and can be discharged almost completely and bounce back (a 200Ah AGM is equivalent to a 100Ah lithium). There are really only two reasons not to go this way: They don’t like heat, so under-bonnet mounting is not advised, and they cost roughly double an AGM but last five times as long, so the cost is well and truly offset over the life of the battery.

In short, lithium is the bee’s knees. They are smaller, so they can fit behind rear seats in dual cabs, behind fascia panels in wagons, and have enabled campers to take high draw accessories like big screen televisions and induction cookers out bush. The phrase “game-changer” gets thrown around too much for our taste, but lithium really does open up a world of possibilities.

Battery Chargers and Battery Management Systems (BMS)

As the name suggests, these are how you keep your auxiliary battery charged, both when driving and parked up at camp for a day or two. There are three main things to consider before selecting a charger or BMS: The type of battery you have (lithiums and AGMs require different charging profiles); the maximum charge voltage and the maximum charge current of your battery.

Essentially you have to match your charger to your battery. An AGM with a 30A maximum charge current won’t last long when paired up with a 50A current charger. By pairing them up correctly, your battery will not only last a lot longer, but reach its maximum state of charge more efficiently, so getting it right is important.

While there are several means of charging a second battery, from the boat switches used by your Great Grandad to the microprocessor-driven battery isolators, which are still working to this day, but are starting to get outdated.

The two main options we will be focusing on are DC-DC chargers, and full Battery Management Systems.

DC-DC chargers are the more common choice because they’re significantly cheaper, and can basically be a set-and-forget unit that handles it all for you, including MPPT regulation (fancy way of saying it manages solar charging), voltage boosting for vehicles equipped with smart alternators (which are not smart at all) and can even be configured to jump your starting battery from your auxiliary in a pinch. They were the best thing ever until Battery Management Systems came along.
A BMS is basically a Brain, in charge of all the 12V components in the vehicle. They can charge all types of batteries, it can be plugged into 240V mains for faster charging, provide maintenance charging and top up charging for lithium batteries after a deep discharge; and they’ll connect to your smart phone and tell you everything about your battery system, how’s that for features. They can also integrate your accessory fuse panel, so you can control your fridge temps, camp lights, stereo, and anything else that uses electricity in your vehicle. They are a do it all unit, and if the budget is there, a BMS should be too.

Integrating Solar Power for Camping

Solar is another item that should be integrated into everyone’s battery system. Why? Because it allows you to keep your batteries topped up while you’re stationary, like when you’re kicking back on the beach for a few days and don’t want your bevvies getting warm.

There’s a lot that goes into selecting the right panel for you. Poly or mono-crystalline; which wattage to go for; hard-mounted or portable etc. The answer is subjective, and you should buy what works for you (having both is best. One for when driving, one for getting the best angle to the sun’s position when at camp). As for poly vs. mono, Mono-crystalline is the better choice. Without diving too deep in the differences, here are the important points. Mono-crystalline solar panels have a higher efficiency and sleek appearance. They are made from a single, high-purity silicon crystal, which allow electrons to move more freely, resulting in better energy conversion. This means they generate more electricity with a smaller footprint, making them ideal for rooftops or areas with limited room. Additionally, Mono-crystalline panels tend to perform better in low-light conditions and have a longer lifespan.

Wattage can be quite a simple decision, we suggest you buy the one with the most watts, and with the correct dimensions for your planned location, within your budget. From there you need to look at the regulator side of things. Again, it’s a long and boring story, but get a Multi Power Point Tracking (MPPT) regulator. Just keep in mind that most BMS’s and a lot of DC-DC chargers will already have these included, so be careful not to spend money twice if you don’t need to.

Other Key Components of a Camping Battery Set-Up

We’ve covered the main parts of a good 12V system, but there’s a lot more gear you can run (and in some cases should run). Here’s a quick rundown on some of the other products available:

Power Distribution Panel

Power distribution panels are basically a ready-made switch panel that can incorporate charging outlets, Anderson plugs and accessory fuses in a single location. They can often make other 12V installs a lot easier, neater and cheaper.

Shunts

A shunt is a fancy battery monitor that connects to your smart phone allowing you to access the battery’s info. Some can often have extra info like fridge temps and which 12v accessory is drawing what amount of power etc. All available from the comfort of your camp chair. Sweet.

Low Voltage Protectors

The good thing about lithium is how far you can discharge them, basically it’s safe to aim for 80%. However, when you do deeply discharge them, you can do so without knowing it and suddenly you’re without power. A low voltage protector will do what it says on the box and sense when the voltage drops below a pre-set figure and cut power to prevent you from draining your battery to zero. Why would you want that? Because in a deep enough state of discharge, lithiums will not be able to be charged by your vehicle’s alternator, it simply doesn’t have the juice to bring it back to life. And this is when you’ll need a…

240V Charger

These allow the 12V system in your car to be plugged into the wall in your garage at home. Not only will they revive a completely drained lithium battery, but they’re a great way to top things off before a trip or keep things trickle fed when the vehicle is not in use. For any lithium system, we reckon these are a must-have.

Inverters

An inverter takes a 12V input (from your 4WD) and outputs 240V (just like your home), allowing you to run household appliances, obviously within reason. Choosing an inverter is, again, a whole new discussion. The short version is to work out what 240V accessories (stuff with a household electrical plug) you want to run at camp and determine the wattage you’ll need to run them, then add 20% on top for safety.

Say you want to bring a 1000W microwave along, you’re better off sourcing an inverter that’s 1200W or higher.

Now, with that being said, it’s a lot more expensive to run larger (2000W and up) inverters, everything from having to purchase a larger battery (200Ah lithium for a 2000w inverter) down to having to run thicker cabling, which can add up quickly. Also, get a Pure Sine Wave unit because they’re friendly to sensitive electronics. Don’t run the risk of melting your phone.

Installation Tips and Best Practices

If you absolutely have to install your second battery under the bonnet, then an auxiliary tray should be on the shopping list to get it mounted. If you’re going lithium, then you have a lot more options, particularly with the slimline range of batteries. We have mounted them behind dual-cab seats, behind trim panels in cargo areas, in custom made enclosures, and put them down the sides of drawer systems – the options are endless. One thing to remember is that vibrations can be a battery killer, so keep it as secure as possible.

With your battery in place, you’ll ideally mount things like your BMS, DC-DC charger, shunt, 240V charger, low battery protector and fuses nearby to minimise excess cabling running all over the shop. It’s also a good idea to mount a distribution box nearby but keep it easily accessible when at camp.

As for cabling, this is an area that’s often overlooked.

Using under or over-sized cable can be filled with danger and unexpected accessory performance, so getting it right is incredibly important. The two big factors are whether the cable you’re using can handle the current you’ll be sending through it and the amount of voltage drop that will occur along its length.

Let’s say you want to run a 60W accessory on a cable.

Remember:

We know the voltage will always equal 12V (it’s actually 13.8ish when the vehicle is running, but let’s not get sidetracked). So, our equation looks like:

60W/12V = 5A

Now, it’s not a great idea to have cabling run at the pointy end of its capacity, so bypass the 5A cable and go for a 7.5A or 10A cable in this case.

As for voltage drop, the mathematics behind this are both extensive and brain-melting. Over the distance of a 4X4, it shouldn’t really be too much of a concern, especially if you’re using the right cabling for the current. Short answer: don’t make your cabling longer than it needs to be without making them overly tight. If the distance you need to cover is 1500mm in a straight line, adding an extra 100mm will be plenty, you don’t need to throw 2000mm at it.

Maintaining Your Camping Battery Setup

The easiest method of keeping your 12V set-up fresh is to drive the vehicle regularly. If it’s a weekends or trips-only rig, then lithium tends not to statically discharge like AGM and lead acid batteries do, so it should be ready to go when you are, but if it needs it, plug the 240V charger in or put an external charger on trickle feed a day or two before you leave.

When you’re on your trip, daily inspections of the terminals, contacts and joins are always a good idea too, and make sure you keep an eye on your monitor to ensure things are charging and discharging as they should be. In corrosive environments like the beach with its salt spray, a dab of dielectric grease on all terminals and connections is a good idea.

Troubleshooting Common 12v Issues When Camping

No matter what is going wrong with your 12V system, there are several checks you can and should make:

· Check fuses, including fuse holders and fuses that still look good with your multimeter

· Check terminals and connections are tight and corrosion free

· Check earths, ideally with a multimeter

· Check cabling for damage or kinks (especially earth cables)

· Check relays are operational (try running accessory on another relay)

· Check circuit resistance with a multimeter

Planning Your 12v System Layout

We’ve covered a lot here, so we’ll try to distil it down a bit for you:

1. Work out your required current draw. Maybe add a bit extra on for future accessories.

2. Choose your battery. You have options, but your best option is lithium.

3. Choose your charging system. A DC-DC if you’re on a budget, or a full BMS if you’re feeling like the wallet is heavy.

4. Choose your extras. Solar, Shunts, 240V chargers and an inverter make a lot of sense.

5. Choose your mounting location. Batteries behind seats or out of the way is ideal, choose an easy place for a distribution box, make sure your cabling is also up to the task.

Camping 12v Setup FAQ’s

What is the Best Power Supply for Camping?

In terms of batteries, lithium, hands down. In terms of ongoing power, a generator is also handy (but don’t be that person when the sites are next to each other)

Will a 200W Solar Panel Run a 12V Fridge?

Not on its own, no. But it will top up a battery that is being used to run the fridge. Whether it can do it indefinitely will depend on the fridge’s current draw, and the Solar panels output efficiency. At the very least it’ll make the draw on the battery a lot slower.

Is a 100Ah Battery Enough for Camping?

Yes, provided your current draw doesn’t exceed 80A, or 50A if using an AGM battery without a charging current source. A lot of people run a dual-battery with this capacity. And as we highlighted earlier, it can easily be chewed up by a fridge, lights and small charger.

How to Power Electronics When Camping?

Most handheld electronics can be charged from a USB (or similar) port that’s tied into your 12V set-up. For 240V-only electronics you will need to use an inverter. For high draw 240V electronics (induction cookers, microwaves etc.) you will need a powerful lithium (200Ah+) and inverter (2000W+) set-up with the appropriate heavy-duty cabling to handle the required current.