Battery calculators
Runtime, charging, and charge level
- BatteryOpen calculator
Battery Percentage
Find remaining charge as a percentage of full capacity.
- BatteryOpen calculator
Battery Runtime
Estimate how long a battery lasts at a given power draw.
- BatteryOpen calculator
Battery Charging Time
Calculate how long it takes to charge a battery at a given current.
- BatteryOpen calculator
Battery Energy Calculator
Calculate battery energy in watt-hours from amp-hours and voltage.
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Battery Depth of Discharge Calculator
Calculate how much of a battery's capacity has been used (DoD %).
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Battery Efficiency Calculator
Calculate round-trip efficiency from energy out and energy in.
- BatteryOpen calculator
Battery Series & Parallel Calculator
Calculate pack voltage, amp-hours, and watt-hours from series/parallel cell layout.
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Battery C-Rate Calculator
Find discharge C-rate and runtime from capacity and load current—updates live.
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Inverter Loss Calculator
Convert DC input watts to AC output and show power lost as heat in the inverter.
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Home Backup Battery Sizing Calculator
Size a backup battery bank for essential loads, runtime, voltage, and depth of discharge.
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Battery Voltage Drop Calculator
Estimate DC wire voltage drop and voltage at the load from amps, length, and system voltage.