LiFePO4 vs AGM Batteries for Van & RV Builds: The Real Comparison
If you're sizing a house battery for a van or RV build, the LiFePO4 vs. AGM decision is the one that shapes your budget, weight, and how much usable power you actually get. Here's the honest breakdown for US builds.
Size your battery automatically
Our free calculator recommends the right battery type and capacity based on your daily usage — no sign-up required.
Usable capacity is the big one
- AGM: safe to discharge to about 50% — a 100Ah AGM gives you ~50Ah usable.
- LiFePO4: safe to discharge to about 80% — a 100Ah LiFePO4 gives you ~80Ah usable.
That means a single 100Ah LiFePO4 battery delivers more usable energy than a 100Ah AGM, and roughly matches two AGMs in series — at about a third of the weight.
Weight and size
LiFePO4 batteries weigh roughly half as much as an equivalent AGM — a 100Ah LiFePO4 is around 22-25 lbs vs. 60-65 lbs for AGM. For a build watching payload (especially on a smaller van or 4x4), that difference adds up fast across a multi-battery bank.
Lifespan and cost over time
- AGM: 300-500 cycles to 50% depth of discharge — roughly 1-3 years of daily van use.
- LiFePO4: 3,000-5,000 cycles to 80% depth of discharge — often 8-10+ years.
AGM is cheaper upfront (a Renogy 100Ah AGM runs around $200 vs. ~$220 for a LiTime 100Ah LiFePO4), but on a cost-per-cycle and cost-per-usable-Ah basis, LiFePO4 wins decisively for anyone living in the van more than occasionally.
Charging differences
LiFePO4 accepts a much higher charge rate and a flatter voltage curve, so it charges faster from solar and the alternator. The key requirement: your charge sources need a LiFePO4-compatible profile. Most modern MPPT controllers and DC-DC chargers (Victron, Renogy) have one built in — see the charging systems guide for setting these up correctly.
Don't charge LiFePO4 below freezing
Charging a LiFePO4 cell below 32°F (0°C) causes permanent damage through lithium plating. Quality batteries have a BMS that blocks charging automatically in the cold — but that means your solar or alternator charging simply won't work until the battery warms up, unless it has a self-heating function.
Which should you pick?
- Weekend/occasional use, tight budget: AGM is a reasonable, proven choice.
- Full-time living, solar-dependent, weight-conscious, or running an inverter/induction cooking: LiFePO4 is worth the cost.
US picks: LiTime 100Ah ($220) and 200Ah ($399) for budget LiFePO4, Battle Born 100Ah Heated ($799) for premium cold-weather use, Renogy Deep Cycle AGM 100Ah ($200) if you're going AGM.