There is a question every Australian caravanner, camper trailer owner, and 4WD tourer eventually arrives at, usually after their second AGM has died at half its rated lifespan: Should you keep replacing absorbed glass mat batteries every two or three years, or finally make the jump to lithium iron phosphate?
After watching this transition play out across thousands of Outbax customers, the answer is not subtle. For the overwhelming majority of camping and RV use cases in Australia, a 12V 100Ah LiFePO4 battery wins. It gives you roughly twice the usable energy from the same amp-hour label, around 60 per cent less weight, four to five times the cycle life, and a flatter voltage curve that keeps fridges, inverters and 12V appliances running properly down to a low state of charge. AGM still has a defensible case in a few specific scenarios, which we will get to honestly, but the days of AGM being the safe default for caravan and 4WD power are numbered.
Here is the comparison in the detail it actually deserves.
Gentrax 12V 100Ah Lithium LiFePO4 Battery
The Capacity Gap Nobody Warns You About
The single most misleading thing about a battery spec sheet is that 100Ah does not mean 100 amp-hours of usable power. Every quality AGM manufacturer recommends running their battery no deeper than 50 per cent depth of discharge if you want it to live anywhere near its rated lifespan. So a 100Ah AGM, in real touring use, gives you about 600 watt-hours of energy you can actually use without ruining the battery.
A 12V 100Ah LiFePO4 battery, like the VoltX 12V 100Ah Lithium Battery, runs at the full label. The published figure is around 1,200 watt-hours of real, usable energy from a full charge. That is the entire 100 amp-hours, not half of it.
Here’s what one of our customers said:
“I have 4 of these (version with battery monitor) in my caravan to provide 400ah of power. They are honestly brilliant. They do actually provide the rated power, I can hammer these and they just hold up. Running them for over a year now. I highly recommend these batteries as I have the confidence in them when off grid, they run a 3000W inverter at full tilt (Pulling +280A) no problems at all. There may be cheaper and more “premium” expensive batteries out there, just get these, you won’t be disappointed.”
What does that look like in practice? The same VoltX product page tells you directly: a 60-litre camping fridge runs for up to 4.5 days in mild weather, or 2 to 3 days in genuinely hot conditions, on a single fully charged 100Ah pack. An equivalent AGM, run sensibly, gives you roughly half that. Pull half your fridge runtime out of a 30-kilogram lump of lead, and you start to understand why caravan parks across the country are quietly emptying out of AGM batteries.
VoltX 12V 100Ah Lithium LiFePO4 Battery
Cycle Life Is Where the Maths Actually Starts
The claim you see plastered across lithium marketing is that LiFePO4 lasts ten times longer than AGM. The honest version is more useful. A quality 100Ah AGM, treated kindly at 50 per cent depth of discharge, will give you somewhere between 300 and 500 cycles before noticeable capacity loss. The same battery, regularly run flat to 80 or 90 per cent depth of discharge as most caravan owners actually do, will struggle to make 200 cycles.
The VoltX 12V 100Ah LiFePO4 is rated up to 4,000 cycles at 100 per cent depth of discharge. Over five times the cycles at twice the usable capacity is, in any sensible measure, an order of magnitude more deliverable energy over the life of the battery.
The implication for total cost is significant. The standard VoltX 12V 100Ah ships with a 36-month warranty, backed by a 60-day money-back guarantee, and your statutory rights under Australian Consumer Law. The Pro model carries 60 months, or five years. By contrast, a 300-dollar AGM realistically owes you 18 to 24 months of trouble-free service before it starts holding less. Across a five-year ownership window, the cost per usable kilowatt-hour delivered tilts heavily toward lithium even before you factor in the inconvenience of replacement.
Queens 12V 95AH Lithium Iron Phosphate Battery
Weight, Fitment, and What Your Tow Car Notices
A typical AGM 100Ah weighs in at around 28 to 30 kilograms. The VoltX 12V 100Ah LiFePO4 sits around 13 kilograms. On a single battery installation, that is roughly 17 kilograms removed from the draw bar or rear of the vehicle. On a 200Ah dual battery setup, it is more than 30 kilograms. On a 400Ah caravan bank, which is exactly what one Outbax customer review describes when they note running four of these batteries to provide 400 amp hours of power, it is a transformation in towing dynamics.
Fitment is also more forgiving than it sounds. Standard VoltX 12V 100Ah dimensions sit close to a Group 27 AGM footprint, making most replacements straightforward. For under-seat installations and slim battery boxes, the VoltX slimline blade format, such as the VoltX 12V 200Ah Slim Lithium Battery and the VoltX 12V 100Ah Blade Lithium Battery, drops into spaces a standard AGM was never going to fit anyway.
Here’s what one of our customers said:
“Have installed this in my 80 series as the house battery. Absolutely stoked. It fits well and runs well as advertised.
Recharges really quickly (I’m using a Outbax 200W panel via a BMPRO dcdc charger).
Easily runs my 1500W inverter, fridge, usb ports for charging, oven etc.
Love the LCD screen. Easy to see where the battery is at without having to go into the shunt app.”
Charging Is Where Most People Get Caught Out
Three things change when you switch from AGM to LiFePO4, and getting any of them wrong is the most common reason customers ring Outbax support after an upgrade.
The first is the AC charger. A seven-stage charger with an aggressive equalisation phase, designed for AGM, can confuse a LiFePO4 battery management system or simply fail to fully charge it. You want a charger with a lithium profile. The compatible VoltX SRNE 50A AC LiFePO4 Charger will take a flat 100Ah pack to fully charge in roughly two hours, which is itself a step change from the eight to twelve hours an AGM typically needs.
The second is alternator charging. LiFePO4 accepts current aggressively, which is brilliant for fast solar and AC charging, but risks overloading a stock alternator if you wire it directly. A DC to DC charger between the alternator and battery is the right answer for any vehicle setup, not optional.
The third is the solar regulator. Most modern MPPT regulators have a lithium setting. Use it. The default lead-acid profile will not fully charge a LiFePO4 pack and will give you a gradual capacity creep downward over a touring season.
The good news on every front is that the VoltX battery itself ships with an internal battery management system that protects against overcharge, overdischarge, overheating, and short circuiting, so the consequences of a charging mistake are recoverable rather than catastrophic. The pack is built from prismatic cells and tested to deliver 100 per cent of the capacity printed on the label, which is more than can be said of many of the no-name lithium imports doing the rounds online.
VoltX 12V 100Ah Bluetooth Daly Lithium LiFePO4 Battery
How They Handle a Real Australian Summer
LiFePO4 chemistry is rated for an operating window that comfortably covers Australian touring conditions, but heat still matters. A battery sitting in a black battery box on a roof rack in 45-degree ambient is not having a good time, regardless of chemistry. The practical advice is the same as it has always been with AGM: shade the battery, ventilate the space, and keep it away from the engine bay if at all possible.
Where the chemistries diverge is in the cold. LiFePO4 batteries can discharge happily well below freezing, but should not be charged below zero degrees Celsius. For most Australian touring, this is irrelevant. For anyone planning alpine work or Tasmanian winters, it is a real consideration, and AGM is more forgiving here. It is one of the few remaining cases where the older chemistry has an honest argument.
The Five-Year Cost Picture
Take a working caravanner spending around 300 dollars on a quality AGM 100Ah and replacing it every two and a half years. Across five years, that is two batteries, 600 dollars, and roughly 1,200 watt-hours of total deliverable energy across the whole period if you are careful with the depth of discharge. If you are not, that figure drops further.
The same caravanner buying a single VoltX 12V 100Ah LiFePO4 for around 700 dollars, used at full depth of discharge across more than 1,500 cycles inside the warranty window, gets several multiples of that deliverable energy from a single battery. The Pro model, with its 60-month warranty, extends the calculation further. On a per usable kilowatt-hour basis, lithium is genuinely cheaper than AGM well inside the warranty period, before you even account for the fuel saved on lighter towing or the avoided headache of mid-trip battery failure on a remote track.
When AGM Still Has a Case
Three buyers should still consider AGM. Anyone who genuinely camps once or twice a year and lets the battery sit in a shed for ten months at a time, where the upfront price gap matters more than cycle life. Anyone with a hard budget cap under 300 dollars who would otherwise be tempted by a no-name 400 dollar import lithium with a thin BMS and an unenforceable warranty. And anyone doing serious sub-zero alpine touring with the battery in an unheated location, where the lithium charging cut-off needs careful planning that AGM simply does not require.
For everyone else, which is the vast majority of Australian campers, caravanners, and tourers, the verdict is straightforward.
The Verdict
Lithium wins for camping and RV use in Australia. The VoltX 12V 100Ah LiFePO4 is the closest direct AGM replacement in the Outbax range, ships next business day from the Sydney warehouse, carries a 36-month warranty, sits behind a 60-day money-back guarantee, and is built from prismatic cells tested to deliver 100 per cent of the capacity printed on the label.
For anyone running a fridge, an inverter, lights, a few accessories and a solar input on the road, it is the upgrade that delivers in towing weight, in fridge runtime, in cycle life and in real five-year cost. The only question left for most readers is whether you want the standard 100Ah model, the VoltX 12V 200Ah Pro LiFePO4 Battery, or the VoltX 12V 100Ah Bluetooth Daly Lithium Battery that lets you watch the state of charge from inside the van. All three are the right answer for someone, and any of them is a better answer than buying another AGM.
