Convert mAh to Wh and Wh to mAh - Conversion Calculator
In order to convert mAh to Wh and Wh to mAh one must introduce another value, since basically, mAh describes the capacity of the, for example, a battery, while Wh describes energy provided or stored by a battery, a capacitor, and similar.
In order to convert mAh to Wh and Wh to mAh, feel free to use our online conversion calculator.
Published: March 11, 2023.
How to Convert mAh to Wh and Wh to mAh?
In order to convert mAh (milli Ampere-hours) to Wh (Watt-hours), the following formula must be used:
E (Wh) = U (V) * C (Ah)
where U (V) is a voltage of, for example, battery.
If the battery capacity (C) is given in mAh (milli Ampere-hours, one thousendth of an Ampere-hour), we must use these formulas:
C (mAh) = C (Ah) * 1000 → C (Ah) = C (mAh) / 1000
Thus, we have following:
E (Wh) = U (V) * C (Ah) = U (V) * C (mAh) / 1000
E (mWh) = U (V) * C (mAh)
For more about unit prefixes, feel free to check our SI Unit Prefixes: How Many Watts in Kilowatt? article.
For example:
LR44 battery is an 11.6 x 5.4 mm alkaline battery with an average voltage of 1.3 volts and an average capacity of ~120 mAh - this battery is on average able to store:
E (Wh) = U (V) * C (mAh) / 1000 = 1.3 V * 120 mAh / 1000 = 0.156 Wh = 156 mWh
SR44 battery is an 11.6 x 5.4 mm silver-oxide battery with an average voltage of 1.4 volts and an average capacity of ~200 mAh - this battery is on average able to store:
E (Wh) = U (V) * C (mAh) / 1000 = 1.4 V * 200 mAh / 1000 = 0.28 Wh = 280 mWh
This is one of the reasons why we almost always recommend silver-oxide over alkaline batteries, not just for button/coin 11.6x5.4 mm cells - SR44 battery on average stores almost double the energy of the LR44 battery.
Also, PR44 (Blue Tab) battery is an 11.6 x 5.4 mm zinc-air battery with an average voltage of 1.3 volts and an average capacity of ~650 mAh - this battery is on average able to store:
E (Wh) = U (V) * C (mAh) / 1000 = 1.3 V * 650 mAh / 1000 = 0.845 Wh = 845 mWh
Despite having somewhat smaller voltage than silver-oxide and even alkaline batteries, thanks to their much larger capacity, zinc-air batteries can store ~3x more energy than the silver-oxide batteries and ~5x more energy than the alkaline batteries.
Due to their wet electrolyte, zinc-air batteries die after few weeks, at most. Because of that, they are used in devices where they are discharged faster, like hearing aid devices.
For all other devices, especially devices that are used only occasionally, silver-oxide batteries are recommended.
mAh to Wh and Wh to mAh Conversion Calculators
In order to convert mAh to Wh and Wh to mAh, feel free to use these online conversion calculators - write the values that You have (voltage is required since we are converting two different units) and click 'Calculate' to convert them:
| MilliAmp-Hours (mAh) to Watt-Hours (Wh) |
|
MilliAmp-Hours (mAh): Volts (U): Watt-Hours (Wh): MilliWatt-Hours (mWh): |
| Watt-Hours (Wh) to MilliAmp-Hours (mAh) |
|
Watt-Hours (Wh): Volts: MilliAmp-Hours (mAh): Amp-Hours (mAh): |
Long Story Short: If order to convert Amp-hours or milli-Amp-hours to Watt-hours or milli-Amp-hours, use our online conversion calculator and/or these formulas:
E (Wh) = U (V) * C (Ah) = U (V) * C (mAh) / 1000
E (mWh) = U (V) * C (mAh)
And be very careful about unit prefixes, of course.
