Battery Energy Storage Calculator
Compute nominal and usable energy capacity of a battery bank from its amp-hours, voltage, depth of discharge and round-trip efficiency.
How to Use the Battery Energy Storage Calculator
- Enter the battery capacity in amp-hours.
- Enter the nominal system voltage.
- Enter the allowed depth of discharge.
- Enter the round-trip efficiency.
- Click Calculate.
Use Cases
- •Sizing off-grid solar storage.
- •EV and UPS specifications.
- •Grid-scale battery planning studies.
Formula
E_kWh = Ah × V / 1000. Usable = E × DoD × η_round-trip.
Frequently Asked Questions
What DoD should I use?
Lead-acid batteries are typically limited to 50% DoD to preserve cycle life. Lithium iron phosphate (LFP) routinely allows 80–90%. Check the manufacturer datasheet.
What round-trip efficiency is realistic?
Lithium packs reach 90–96% depending on current and temperature; lead-acid is around 75–85%. Inverter losses are separate.
Does this include inverter losses?
No. Multiply the usable energy by the inverter efficiency (typically 0.92–0.97) to get AC deliverable energy.