How to convert mAh to Wh using our calculator
Our custom-made calculator is designed to convert charge capacity specified in mAh to energy specified in Wh. Here’s how to use our conversion calculator:
- Input the capacity in mAh
- Choose the desired voltage (if you’re calculating for a power bank, use 3.7V as the base value)
- Click the red “Calculate” button
- See the result
- Click the “Reset” button to run another calculation
mAh to Wh conversion formula
If you want to do the conversion by hand, here’s the formula behind our Wh calculator:
Wh = mAh × V / 1000 mAh stands for milliamp-hour
and it’s the unit of electric charge and commonly used to express the capacity of the small batteries. mAh specify the total amount of charge passing through a point in a certain period of time. A battery with a higher mAh value will power a system for a longer time. It is typically used to specify and describe the total amount of energy retained by a battery. Wh
stands for Watt-hour and it’s another commonly used and accurate unit for comparing the capacity of batteries that have different voltages. Wh is calculated from the voltage (V) provided by a battery, multiplied by current (amps) supplied by a battery for a certain time (usually in hours). Generally, we use mAh for cells and batteries, whereas watt-hours for energy storage systems. mAH does not indicate the power capacity of a battery as two batteries with the same mAh value may deliver a different amount of energy
. We must consider another variable, the Volt, for calculating the power capacity denoted by Wh. Volt refers to the difference in the electric potential between the positive and negative terminals of a battery. It is the force required to overcome the resistance and move the electrons to make the battery work.
How many volts do power banks have?
The voltage of a power bank depends upon the battery cells used and can fluctuate between brands and models. However, generally speaking, the battery cells in power banks are either Li-Poly or Li-Ion
, both of which are 3.7 Volt
. It’s also worth mentioning the fact that if the voltage is smaller than the voltage of your device, charging cannot occur. This is why all power banks come with a step-up voltage converter to produce the 5 Volts required for charging an external device. New power banks are now available in the market, supporting the fast-charging features and often delivering a voltage of 9 Volt. Most of the power banks have battery cells internally connected in series to achieve the required voltage. For example, if a power bank has four Li-ion cells connected in series, it will have an overall voltage of 14.8 Volts. A lot of people don’t know if they’re allowed to take power banks on planes
or not. It is very important to know the Wh value of your power bank to comply with the rules and regulations referring to power banks and batteries in the travel industry. For example, you cannot take a battery exceeding 100 Wh on planes.
Common power bank capacities from mAh to Watt-hours
Here are some very common power bank mAh capacities and their values in Wh:
- 5000mAh -> 19Wh
- 10000mAh -> 37Wh
- 15000mAh -> 56Wh
- 2000mAh -> 74Wh
- 2000mAh -> 74Wh
- 3000mAh -> 111Wh
- 5000mAh -> 185Wh
Hopefully, now you understand better the relation between mAh and Wh and can confidently make the conversion. In case you have any questions regarding the formula or our calculator, please drop us a line via the contact form.