Calculate how long a battery will power your LED lighting. Supports lead-acid, AGM, LiFePO4, and lithium-ion chemistries with depth-of-discharge limits, Peukert correction for high discharge rates, temperature derating, and emergency lighting compliance check for BS 5266 / NFPA 101.
Battery chemistry
Flooded lead-acid
50% DoD max
Standard SLA / car battery
AGM / Gel
60% DoD
Sealed, maintenance-free
LiFePO4
80-90% DoD
Best cycle life, safest Li
Li-ion (NMC)
80% DoD
High density, common
NiMH
70% DoD
Emergency lighting packs
Alkaline (disposable)
90% usable
Single use / portables
Battery specification
From battery label — C20 or C10 rating
How much of capacity to use before recharge
LED load
For battery sizing recommendation
Please enter battery capacity and LED load.
Estimated runtime
0 hrs
0Wh
Usable energy
0A
Current draw
0Ah
Ah needed (target)
0h
Charge time
Battery state — usable vs reserved capacity
Meets 3-hour emergency standard
Runtime at different load levels (same battery)
LED loadCurrentRuntimePeukert adj.
Batteries needed for target runtime (3h)
Battery sizeQuantityTotal WhRuntime
Battery selection tips
Battery
Usable energy
LED load / current
Calculated runtime
Temperature factor
Charge time
Cycle life (est.)
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