Generally, a 24V 200Ah battery can last approximately 4. 8 kilowatt-hours (kWh) of use. However, the exact duration varies based on several factors like load demand, battery efficiency, and environmental conditions. What Do Amp-Hours (Ah) And Voltage (V) Mean On A. To calculate how long a 24V battery will last, we can use the follow formula: In this formula: Battery Capacity (Ah) refers to the amp-hour rating of the battery, indicating how much current it can supply over time. To figure out how long it'll run your devices, just use this simple math: Runtime = Battery Energy ÷ Your Device's Power Here's what that looks like in real life: Keep in mind, these are best-case. Use our lithium battery runtime (life) calculator to find out how long your lithium (LiFePO4, Lipo, Lithium Iron Phosphate) battery will last running a load. Featuring A-grade lithium c expansion capacity and has a longer lifespan of 10-20 years. I m (LiFePO 4) will last about 8 hours running a 500-watt load.