Battery chemistry comparison
LiFePO4 vs AGM battery runtime
Two batteries with the same voltage and Ah label can deliver different planning runtime. The main difference in this simple comparison is how much nominal energy you choose to use and how efficiently the battery delivers it.
Compare the same nominal battery
A 12V 100Ah battery stores 1,200Wh nominal regardless of chemistry. Runtime changes after depth of discharge and battery efficiency are applied.
| Planning preset | DoD | Battery efficiency | Usable Wh |
|---|---|---|---|
| LiFePO4 | 90% | 95% | 1,026Wh |
| AGM / gel | 50% | 85% | 510Wh |
At a steady 100W DC load, those editable assumptions produce about 10.3 hours for LiFePO4 and 5.1 hours for AGM. They are planning values, not universal manufacturer limits.
AC loads need another adjustment
An AC appliance adds inverter conversion loss and idle draw. Low-power loads can be affected noticeably by inverter idle consumption.
Runtime is not the whole comparison
Check charge limits, temperature behavior, discharge current, weight, cycle requirements, BMS behavior, charger compatibility, ventilation, and manufacturer instructions. Do not replace a chemistry review with one runtime number.
Compare your documented values
Select a preset in the battery runtime calculator, then replace it with the current limits from the battery documentation. Use the battery sizing calculator when you know the required energy and need capacity instead of runtime.