LiFePO4

LiFePO4, or lithium iron phosphate, is the lithium chemistry used in nearly all RV house batteries marketed as lithium today. Compared with lead-acid or AGM batteries of the same physical size, LiFePO4 weighs roughly half as much and delivers far more usable amp-hours, since it can be discharged much deeper without damage.

The tradeoff is compatibility. LiFePO4 needs a charger, converter, or solar charge controller with a lithium-specific charge profile, and it performs poorly or can be damaged charging below freezing unless the battery has a built-in heating pad. Many owners upgrading from lead-acid also need to update their converter or inverter-charger at the same time.

A common mistake is dropping a lithium battery into an older RV's factory charging system without checking the charge profile, which can undercharge the battery or trip its internal protection circuit. Always confirm charger compatibility and low-temperature charging behavior before switching chemistries, and check whether the battery has a built-in heater if you plan to camp or store it somewhere cold.