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Batteries calculators

Work out how big a battery bank you need, how long it will last, and what its voltage is telling you. These calculators cover lead-acid, AGM, gel and lithium (LiFePO4) leisure batteries for vans, RVs, boats and off-grid cabins.

Amp hours to watt hours calculatorConvert battery Ah to Wh and kWh at any voltage.Watt hours to amp hours calculatorConvert Wh or kWh to amp hours at any battery voltage.mAh to Wh calculatorConvert power bank and cell mAh to watt hours (airline limits too).Battery run time calculatorHow long a battery will power a load, for lead-acid or lithium.Battery bank size calculatorHow many amp hours you need for your daily use and days of autonomy.Battery series and parallel calculatorTotal voltage, Ah and Wh when wiring batteries in series or parallel.Battery voltage and state of charge calculatorEstimate state of charge from resting voltage, lead-acid or LiFePO4.Battery C-rate calculatorConvert between C-rate and amps for charging and discharging.Peukert's law calculatorHow high currents reduce real lead-acid capacity and run time.Trolling motor battery calculatorRun time of an electric outboard or trolling motor on your battery.UPS runtime calculatorHow long a UPS or battery backup will keep your equipment running.Battery cost per cycle calculatorCompare the true lifetime cost of LiFePO4 and lead-acid batteries.E-bike battery range calculatorRange per charge from battery Wh and your riding style.

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