Watts to Joules
Power converter

Amp-hours to Watts Calculator

Calculate the total power output in watts a battery can sustain.

Ah
V
h

How Ah to Watts works

If you have a battery rated in Amp-hours (Ah), you can figure out how many watts it can output continuously by knowing its voltage.

First multiply Ah by Volts to find total Watt-hours (Wh) capacity, then divide by the hours you need it to run.

Formula
1Watts = (Ah × Volts) ÷ Hours

Keep in mind most batteries (like Lead-Acid) shouldn't be drained below 50% capacity.

Ah to Watts conversion table

Reference Table4 rows
Sustained wattage from a 100Ah battery (12V).
BatteryRun TimeSustained Power Output
100Ah at 12V
1 hour
1,200 W
100Ah at 12V
5 hours
240 W
100Ah at 12V
10 hours
120 W
100Ah at 12V
24 hours
50 W

FAQ: Ah to Watts

How many watts is a 100Ah 12V battery?

A 100Ah 12V battery stores 1,200 Watt-hours of energy. It can power a 1,200W load for 1 hour, or a 120W load for 10 hours.