RV Battery Selection Guide
How to choose the right LiFePO4 battery for RV applications — capacity sizing, voltage, charging, and what to watch when replacing lead-acid.
Sizing your battery bank
Start by listing everything the battery needs to power and for how long. A typical RV setup includes lights, water pump, refrigerator, fans, and device charging. Add up the watt-hours per day, then divide by your system voltage to get the Ah you need. Use our Battery Capacity Calculator to run the numbers.
Rule of thumb: most weekend RVers do well with 100–200Ah at 12.8V; full-timers with larger loads often need 200–400Ah or more.
12V vs higher voltage
Most RVs are built around 12V house systems, so 12.8V LiFePO4 (4S) is the natural drop-in choice. If your total inverter load regularly exceeds ~2000W, consider whether a 24V or 48V architecture would reduce cable sizes and losses — but this usually means a bigger electrical refit.
Discharge and BMS
Check the battery’s continuous discharge rating against your largest loads. A 100Ah battery with a 100A BMS supports about 1280W continuous at 12.8V. If you run a microwave or air conditioner through an inverter, make sure the BMS and wiring can handle the surge.
Charger compatibility
LiFePO4 needs a charger with a lithium profile (typically 14.2–14.6V absorption for 12.8V systems, no float). Older RV converters designed for lead-acid may undercharge lithium batteries or, worse, apply an equalization mode that damages them. Verify your converter, solar controller, and alternator charger (DC-DC) all support LiFePO4 — or plan to upgrade them.
Cold weather limits
LiFePO4 batteries should not be charged below 0°C (32°F) — doing so causes permanent lithium plating. Discharging in the cold is fine within limits. If you camp in freezing weather, choose batteries with low-temperature charge protection (the BMS cuts off charging) or built-in heating, and mount them in a heated compartment when possible.
Replacing lead-acid: what changes
- Usable capacity doubles: a 100Ah LiFePO4 gives roughly the usable energy of a 200Ah lead-acid bank.
- Weight drops sharply: important for payload limits and handling.
- Charging is faster and more efficient, but requires compatible equipment (see above).
- Voltage stays flat through most of the discharge — fuel gauges calibrated for lead-acid voltage sag will read incorrectly; use a shunt-based battery monitor.