A practical field guide to sizing, charging and choosing a lithium battery that keeps the fridge cold and the lights on, wherever you decide to pitch.
Key takeaways
- Most weekend campers are comfortably covered by a single 100Ah LiFePO4 battery, which stores about 1,280 watt-hours of usable power.
- Work out your daily power use first, then add roughly 25 per cent as a buffer before you choose a capacity.
- Pairing the battery with a solar panel is what turns a weekend kit into a genuine multi-day off-grid camp.
- LiFePO4 batteries weigh far less than the old lead-acid type, last around 4,000 charge cycles and can be safely run almost flat.
There is a quiet test that every camper eventually faces. You arrive at a site with no power, set up the fridge, string up the lights, then lie awake wondering whether any of it will still be running by morning. At Outbax, we have run that experiment several times, and the honest answer is that it comes down to two things: how much power your gear draws, and how much your battery can store. Get those two numbers talking to each other, and a LiFePO4 lithium battery will keep a camp running for days without a generator anywhere in earshot. This guide walks through how to do exactly that, using real figures rather than vague promises.
What a Campsite Actually Runs On
Before you can choose a battery, it helps to know where your power really goes. The biggest draw at most camps is the fridge. A typical 12-volt camping fridge pulls somewhere between 30 and 50 amp-hours over a full day, depending on the weather and how often the lid gets opened. Add LED lighting, a few phone and tablet charges, maybe a fan or a water pump, and most campers land between 50 and 70 amp-hours of use per day.
The simplest way to plan is to think in watt-hours. A 100Ah, 12-volt LiFePO4 battery, such as the VoltX 12V 100Ah LiFePO4 Battery, stores about 1,280 watt-hours. Because lithium iron phosphate chemistry lets you run a battery down to almost empty without harming it, nearly all of that is usable power. That is the part that surprises people upgrading from an older battery, where only about half the rated capacity was ever safe to draw on.
Gentrax 12V 200Ah Lithium LiFePO4 Battery
Working Out the Size You Need
Here is a popular method you can use to size your battery before every trip, and it takes about two minutes.
- Add up the daily amp hours of everything you plan to run.
- Add roughly 25 per cent on top as a safety buffer.
- Round up to the nearest battery size.
If your fridge, lights, and charging come to around 60 amp-hours a day, a single 100Ah battery covers a weekend comfortably. Heading away for four or five days, running a larger fridge, or powering an inverter for a kettle or coffee machine? Step up to a 200Ah battery. For an extended off-grid base camp or a setup that has to feed an inverter and air conditioning, the 300Ah option stores 3,840 watt-hours and gives you real headroom. The rule of thumb is simple: nobody has ever stood at their campsite at six in the morning wishing they had bought a smaller battery.
Here’s what one of our customers said:
“Ordered 3 batteries online, showed up as promised 2 days later, installed & charged up & no problems. Much lighter than the old AGM’s.”
What Real Campers Are Actually Running
The figures above are reassuring, but field reports are better still. Among the customer reviews on Outbax, one camper described running two VoltX 12V 200Ah Pro LiFePO4 Batteries wired together to feed a 2,500-watt inverter, staying off-grid for four days while running air conditioning for about three hours a day, plus an air fryer and a coffee machine, all topped up by 650 watts of solar. By the end of the week, the batteries still showed a full charge.
Another ran a 60-litre fridge non-stop on a 120Ah setup. Overnight, it dropped to around 75 to 80 per cent, then climbed back to full by mid-morning once the solar woke up. That is the pattern worth copying. A battery sized for your draw, kept topped up through the day by the sun, will outlast almost any trip you throw at it.
Here’s what one of our customers said about the VoltX 12V 200Ah Battery:
“I have been using 4 of these for 2 years now, these shown i think are a newer model but i have had a PERFECT run with them, i cannot overcharge them and they turn off if they get too low, they work both in series and parallel perfectly as i run them as a 24v system. The staff are amazing and will answer all your questions…”
Gentrax 51V 100Ah Lithium LiFePO4 Battery
Keeping the Battery Topped Up
A battery stores power. It does not make it. For anything longer than a couple of nights, you need a way to put energy back in, and most seasoned campers use two methods together. The first is solar: a panel or two on the roof or laid out at camp will recharge the battery through daylight, which is exactly what those reviews describe. The second is charging from your vehicle as you drive, using a DC-DC charger that safely tops the battery up from the alternator. When you do plug into mains power, a compatible lithium charger should be set to around 14.2 to 14.6 volts for a 12-volt battery, which is the range these cells are designed for.
Will It Fit, and Will It Last?
Two practical worries come up again and again. The first is space. If your battery has to slide behind a seat or into a narrow box, a slim or blade-shaped battery is built for exactly that. For instance, our VoltX 12V 200Ah Slim Lithium Battery drops neatly into spaces left by an old 100Ah battery with only minor adjustment needed.
The second worry is durability, and this is where lithium quietly shines. Quality LiFePO4 batteries are built with sealed ABS casings and aluminium cell protection, with a carry handle moulded in. They are made to be thrown in the back of a four-wheel drive and bounced down a corrugated track, not babied. With roughly 4,000 charge cycles in them, a good unit will see out seven years or more of regular weekends.
VoltX 48V 100Ah LiFePO4 Golf Cart Battery
Lithium Against the Old Lead-Acid Battery
If you are upgrading from a traditional deep-cycle battery, the contrast is stark. A LiFePO4 battery weighs between 50 and 70 per cent less than the lead-acid equivalent, so a 100Ah unit like the Gentrax 12V 100Ah Lithium Battery comes in at roughly 9.5 to 12 kilograms rather than something you would rather not lift twice. You can use the full-rated capacity rather than half. Efficiency sits above 95 per cent, and the cycle life runs into the thousands rather than the few hundred, which a lead-acid battery manages.
The catch is the upfront price. Lithium costs more on day one. But spread it across the years and the trips, and set it against the lead-acid batteries you would otherwise replace several times over, and the cost-per-camp drops below what you were paying before. If you camp once a year, your current battery is probably fine. If camping is part of who you are, lithium is the cheaper road in the long run. It is worth reading a fuller lithium versus AGM comparison if you are still weighing the two.
Choosing Between VoltX and Gentrax
Outbax sells its lithium range under two house brands. VoltX carries the broadest spread, from the popular 100Ah weekender pack through to the 300Ah unit–the VoltX 12V 300Ah Pro Lithium Battery. Its batteries also use an advanced management system that handles charging, temperature, and cell balancing automatically. Gentrax offers a friendlier-priced 300Ah option for buyers chasing capacity for less. Both come from the same supplier, so the choice comes down to how much you value the extra features and review history behind the VoltX range against the savings on the Gentrax unit.
VoltX 12V 200Ah Slim Lithium LiFePO4 Battery
Buying with Peace of Mind
Choosing a battery you will rely on hundreds of kilometres from the nearest town is as much about the people behind it as the cells inside it. Outbax is an Australian retailer that builds its VoltX and Gentrax batteries for local conditions and stands behind them with a 3 to 5-year warranty and a 100 per cent capacity assurance. Orders are dispatched within a day and shipped free across the country, and there is a 60-day window to send a battery back if you have second-guessed the size. There are real people on the phone throughout the week if you would rather talk it through first. Once you know the capacity your trip calls for, you can compare the full LiFePO4 battery range in one place and pick the one that matches your power budget.
