20,000 mAh to Wh

20,000 mAh is 74 Wh at 3.7V (standard Li-ion). The energy in watt-hours depends on the battery voltage.

20,000 mAh at Every Voltage

VoltageContextEnergy (Wh)
3.7VLi-ion cell (phones, power banks, laptops)74 Wh
7.4V2S Li-ion (cameras, drones)148 Wh
11.1V3S Li-ion (laptops)222 Wh
12VLead-acid (cars, UPS)240 Wh
14.8V4S Li-ion (laptops)296 Wh
24VE-bikes, power tools480 Wh
48VE-bikes, solar batteries960 Wh

Other mAh Values

This calculator provides estimates. Actual battery capacity varies with age, temperature, and discharge rate.