Battery Runtime Calculator
Determine how long your battery bank will last during a power outage. Works for lead-acid, AGM, and lithium (LiFePO4) batteries.
System Details
Depth of Discharge (DoD): 100%
Ah
W
%
Estimated Runtime
--
hrs
Total Energy:
-- Wh
Usable Energy (DoD):
-- Wh
Current Draw:
-- A
Why Battery Type Matters
Batteries aren't just about total capacity; they are about usable capacity. Draining a battery too low can permanently damage it, depending on the chemistry.
- Lithium (LiFePO4): The gold standard for solar generators. Can be safely discharged to 100% (or very close), giving you full use of the rated capacity. They are lighter and last longer.
- AGM (Absorbed Glass Mat): A better version of lead-acid. Generally recommended to discharge only to 50-80%. Going lower shortens life span.
- Lead Acid (Flooded): Traditional car/marine batteries. Should rarely be discharged below 50%. This means a 100Ah battery only provides 50Ah of usable power!
Formula Used:
Runtime = [(Ah × V × DoD) × Eff] / Watts