AC To DC Calculator

This calculator is designed to calculate AC loads to DC battery banks +/- a battery. To compute DC loads to DC battery banks, click here.

AC to DC conversion is not perfectly efficient. To be safer, use the 80% (.8) efficient derate factor.

This calculator computes the number of batteries needed for any application +/- a battery. System is set to +20% (ah X 1.2) to account for wire resistance, resulting voltage loss, heat, and other DC system inefficiencies.

For Critical Applications battery sizing should be a starting point. Unusual circumstances call for an additional 100-500+ ah battery bank.

The computation does not account for losses of up to half ampacity for colder temperatures OR increased self discharge in warmer climates and on older batteries.

System does not account for amperages outside battery possible limits.

As a battery chemically transforms from fully charged to discharged, it’s voltage drops from 13.5 – 10.5 volts for a 12 volt battery. As the voltage drops this affects the amount of amps required to drive a load. (Watts law: amps x volts = watts)

AGM Batteries are not harmed by high amperage charge and discharge so long as the input voltage is carefully regulated.