How to use the UPS Runtime
The Formula
Runtime (hours) = battery watt-hours ÷ load watts. This assumes constant load and ignores inverter efficiency—real runtime is often 10–20% shorter.
Practical Example
Check your UPS specs for internal battery Wh, or multiply Ah × V. For a 12 V 42 Ah battery: 504 Wh.
About UPS Runtime
UPS runtime formula
Runtime (hours) = battery watt-hours ÷ load watts. This assumes constant load and ignores inverter efficiency—real runtime is often 10–20% shorter.
Finding battery Wh
Check your UPS specs for internal battery Wh, or multiply Ah × V. For a 12 V 42 Ah battery: 504 Wh.