AGM vs Lithium RV Batteries: Which One Actually Wins in 2026
Lithium wins for anyone who camps off hookups, on usable capacity, weight and cycle life. AGM still wins for shore-power campers who want a low upfront number and a battery that sits through a cold winter without anything to manage.
AGM vs lithium: the specs that actually differ
| AGM | LiFePO4 | |
|---|---|---|
| Recommended depth of discharge | 50% | 80 to 100% |
| Weight per 100Ah | 60 to 70 lb | 25 to 30 lb |
| Charge efficiency | 80 to 85% | 95 to 98% |
| Full recharge, 100Ah | 6 to 10 hours | 2 to 6 hours |
| Voltage under load | drops steadily | flat until nearly empty |
| Self-discharge | 10 to 35% per month | 2 to 3% per month |
Most of that table is uncontroversial. The row that causes the most confusion is the one nobody puts in a table at all.
Why cycle life numbers are not comparable
Cycle life is not a property of the battery. It is a property of the battery at a stated depth of discharge, and most published numbers leave the second half out.
LiTime publishes three figures for one 165Ah pack. 4,000 cycles at 100% depth of discharge. 6,000 cycles at 80%. 15,000 cycles at 60%. Same cells, same BMS, same product page. The only thing that changed is how hard you work it.
So when one spec sheet says 4,000 cycles and another says 15,000, you are usually not looking at a better battery. You are looking at a different assumption.
This matters here because AGM and lithium are almost never quoted at the same depth. AGM figures assume 50% discharge, which is the deepest AGM tolerates without early failure. Lithium figures often assume 100%, which is the worst case for lithium. Quoted that way, AGM lands at 300 to 700 cycles and lithium at 3,000 to 5,000.
Hold both at the same 50% and the lithium figure climbs past 15,000 on some packs. The real gap is wider than the brochures show, not narrower.
Before you compare two batteries, check the depth each number was measured at. If a seller does not publish it, treat the cycle figure as unverified.
How much usable capacity you actually get
A 100Ah AGM at 12V holds about 1,200Wh. You can use half of it. That is 600Wh per cycle before you start shortening its life.
A 100Ah LiFePO4 holds about 1,280Wh and the BMS lets you take nearly all of it. Call it 1,200Wh.
Same label on the case. Double the working energy. This is why a 200Ah lithium bank replaces a 400Ah AGM bank and still weighs less than half as much.
If you are sizing a bank around this, run the numbers before you buy, not after. Our battery bank sizing guide walks through it.
What happens to lithium in cold weather
This is the one place AGM holds a real technical advantage, and it is narrower than it sounds.
LiFePO4 cannot accept a charge below 32°F without plating lithium onto the anode, which is permanent damage. A decent BMS blocks it automatically. LiTime's 165Ah cuts charging off below 32°F and resumes at 41°F. Discharge is a separate matter and runs fine down to -4°F.
Self-heating packs remove the problem. The Renogy Pro S1 240Ah accepts a charge at -4°F because it warms itself first. Vatrer's self-heating 300Ah does the same for about $60 over the standard version.
AGM charges cold without any of that. What it does not do is hold capacity while cold. Below freezing an AGM's available capacity drops off quickly, so you get to charge a battery that is delivering less.
What each one actually costs per usable kWh
Sticker price is the wrong comparison, because the two chemistries sell you different amounts of usable energy. Cost per usable kilowatt-hour fixes that.
| Battery | Price | Usable | Cost per usable kWh |
|---|---|---|---|
| Vatrer 300Ah | $570 | 3.84 kWh | $148 |
| LiTime 165Ah | $455 | 2.11 kWh | $216 |
| Renogy Pro S1 240Ah | $870 | 3.07 kWh | $283 |
| AGM 100Ah | $200 to $350 | 0.60 kWh | $333 to $583 |
| Battle Born 270Ah | $2,299 | 3.46 kWh | $665 |
Three of the four lithium packs beat AGM's best case. That is the part most comparisons miss, because they stop at the sticker.
Battle Born sits at the top of that table for reasons that are not capacity. Ten-year warranty, US assembly, and support you can reach on the phone. Whether that is worth four times Vatrer's cost per kWh is a judgment call, not a spec.
When AGM is still the right call
Four situations, and they are specific.
You camp on hookups most of the time. Your bank rarely drops below 90%, so the usable-capacity advantage never gets spent.
You will not do a careful install. Lithium wants a compatible charger or a DC-DC converter, and the wrong charge profile is an expensive mistake. AGM forgives more.
You store the rig outside all winter in a cold climate with no shore power. A non-heated lithium pack cannot be charged in that state, and heated packs cost more.
You plan to sell the rig soon. AGM is familiar to buyers. Lithium reads as a niche modification to most of them.
If none of those describe you, the decision comes down to upfront spend. I went deeper on that tradeoff in our LiFePO4 vs AGM vs flooded comparison.
The short version
Compare cycle life only at matched depth of discharge. Compare cost only per usable kilowatt-hour. Do both and lithium wins nearly everywhere except cold storage, DIY-only installs, and resale.
Once the chemistry is settled, picking a specific pack is a separate problem. Start with Best LiFePO4 Batteries for RV.