Touring batteries are the boring decision that secretly runs everything. Get it right and the fridge stays cold, the lights work, the Starlink keeps streaming and you forget the system exists. Get it wrong and you are sitting in the dirt at six in the morning trying to jump start your house battery off the cranker.
For the last decade Aussie tourers had one realistic choice for an auxiliary battery — AGM. Lithium was around but it was reserved for caravans and people with very deep pockets. In 2026 that has changed. Lithium prices have come down, the technology has matured, and you now have a real decision to make. Here is the honest comparison.
Quick answer (TL;DR)
- Pick AGM if your touring is occasional, your power draw is modest (a fridge plus a few lights and phone charging), and you want the lowest upfront spend. Around three hundred dollars buys a solid 100 amp hour AGM.
- Pick lithium (LiFePO4) if you tour for weeks at a time, run a fridge plus a Starlink plus a tablet plus camp lights, and you want to forget about your battery for the next ten years. Expect to spend around nine hundred to twelve hundred dollars for a 100 amp hour lithium.
The short version — lithium gives you roughly twice the usable capacity and a third of the weight, but costs three times as much. Whether that maths works depends entirely on how often you are out and what you are running.
Usable capacity — the number that actually matters
Both batteries are sold as 100 amp hour units. They are not the same thing.
An AGM should not be discharged below about 50 percent state of charge if you want it to last. Drop a 100 Ah AGM to 40 percent regularly and you will be replacing it inside two years. So a 100 Ah AGM gives you around 50 Ah of real, usable capacity per cycle.
A lithium LiFePO4 will happily discharge to 10 or 20 percent state of charge with no real impact on lifespan. So a 100 Ah lithium gives you roughly 80 to 90 Ah of usable capacity per cycle.
That means a 100 Ah lithium is, in practical touring terms, the equivalent of about two 100 Ah AGMs. Which suddenly makes the price gap look more reasonable, especially once you factor in the second battery box, second BCDC charger and the hundred extra kilos.
Weight — and where you put it
A 100 Ah AGM weighs around 28 to 30 kilograms. A 100 Ah lithium weighs around 12 to 14 kilograms. Half the weight, less than half.
That sounds like a marketing line but it matters more than people give it credit for. Most touring 4WDs are already overloaded. Pull the GVM sticker, weigh the rig at a public weighbridge with the camper trailer attached and your gear loaded, and most rigs come back uncomfortably close to or over the limit. Saving 15 kilos out the back of a 79 Series ute is the difference between a happy rear axle and a sad one.
It also matters for where you mount the thing. A lithium under the rear seat or in a slim drawer is a lot easier to live with than an AGM that needs its own ventilated box bolted to the chassis.
Cycle life and lifespan
This is where lithium really pulls ahead.
A quality AGM, treated well (kept above 50 percent, not left flat for weeks, not cooked at 60 degrees in the back of a camper in summer) will give you around 400 to 600 deep cycles. That works out to maybe three to five years of regular touring use. Treat it badly and that drops to one or two years.
A quality LiFePO4 lithium will give you 3000 to 5000 cycles to 80 percent of original capacity. That is closer to ten or fifteen years for the average tourer. The pack will likely outlast the vehicle it is bolted into.
Spread that AUD 1000 lithium over twelve years and it costs roughly the same per year as replacing an AGM every three years.
Cold and hot weather behaviour
Lithium has one real weakness — it does not like being charged below zero degrees. The cells will accept the current but micro plate damage starts to accumulate and the pack life shortens. Most decent LiFePO4 batteries sold in Australia in 2026 have a built in low temp cutoff that simply blocks charging below about zero. Discharging in the cold is fine.
For Tassie winters and high country touring this is something to be aware of. For 95 percent of Australian touring it is a non issue.
AGM does not care about cold but loses around 20 percent of capacity at zero degrees. Both batteries hate being cooked above 50 degrees, which is exactly what happens to anything mounted under a black bonnet in a Pilbara summer. Mount your house battery in the cargo area or under the rear seat, not the engine bay.
Charging — the bit people forget
If you swap from AGM to lithium you will need to update your DC-DC charger to one that has a lithium charge profile. Most BCDC units made in the last five years (Redarc, Projecta, Victron, Renogy) have a switch or app setting for this. If yours is older, factor a replacement into the budget.
Solar regulators are the same story — make sure the controller has a lithium profile, not just a generic AGM curve.
And lithium does not like being trickle charged or float charged forever the way AGM does. Modern smart chargers handle this automatically. Old style trickle chargers do not.
Side by side comparison
| Spec | 100 Ah AGM | 100 Ah LiFePO4 lithium |
|---|---|---|
| Usable capacity per cycle | ~50 Ah | ~80 to 90 Ah |
| Weight | 28 to 30 kg | 12 to 14 kg |
| Typical cycle life | 400 to 600 cycles | 3000 to 5000 cycles |
| Real world lifespan | 3 to 5 years | 10 to 15 years |
| Cold charge limit | No issue, 20 pct capacity loss at 0 degrees | Will not charge below 0 degrees |
| Charge time (full) | ~6 to 8 hours | ~2 to 4 hours |
| Self discharge per month | 3 to 5 percent | 1 to 2 percent |
| Upfront cost (AU 2026) | ~AUD 280 to 400 | ~AUD 900 to 1200 |
| Best for | Weekenders, modest power draw, lowest cost | Long term tourers, heavy power use, weight savings |
Real world tips from people who have done both
- Match the battery to your fridge runtime, not your ego. A 65 litre Engel pulls roughly 25 to 35 Ah per day in moderate weather. Add a Starlink Mini at 30 Ah per day. That is 60 odd Ah a day before phones, lights or anything else. AGM struggles. Lithium handles it without thinking.
- Charging input matters more than capacity. A massive battery with a tiny solar panel and a slow alternator feed is just dead weight. Match your DC-DC charger and solar to the battery, not the other way round. A 25 amp BCDC into a 100 Ah lithium is a sensible match.
- Weigh your rig before you upgrade. If you are already over GVM, the weight saving from going lithium might be the only realistic upgrade you can make.
- Do not mix old AGM and lithium in the same bank. They behave differently under load and the AGM will get cooked. Pick one chemistry per bank.
- Buy from an Australian seller with a real warranty. Cheap online lithium with no local support is a heartbreak waiting to happen the first time the BMS faults out three thousand kilometres from home.
Powering everything else off it
Whatever battery you go with, the rest of your 12V system needs to play nice. Decent fuses, properly sized cable, USB charging that does not melt in summer, and a way to monitor what is going in and out. We have put together a 12V accessories collection with the bits we actually use ourselves on long trips — chargers, monitors, USB outlets and the rest. If you are running a Starlink Mini off the same battery bank, the Starlink Mini accessories range includes the cabling, mounts and adapters that take the guesswork out of integrating it cleanly.
So which one
If you tour two or three weekends a year, run a fridge and not much else, and you do not want to spend a grand to find out you got it wrong, AGM is still a perfectly good answer in 2026. The technology is mature, the warranties are real and you can buy a replacement at any Repco on the way to camp.
If you are out every long weekend, you run a fridge plus comms plus camp lights plus laptop, and you want to stop thinking about whether the battery is going to make it through one more night, lithium is worth the spend. Spread over a decade it is not actually more expensive — and the weight saving alone is worth it for most rigs.
What have you ended up running, and what would you change on your next setup? Drop a comment below — there are a lot of opinions on this one and the more real world experience we share the better the next bloke kitting out a rig will get to choose.
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