Converting energy measurements from kilowatt-hours (kWh) to milliampere-hours (mAh) is a common task for engineers, hobbyists, and anyone looking to understand the capacity of portable power stations or large battery banks. Use our free calculator below to perform the conversion instantly.
Understanding the Conversion: kWh to mAh
To understand how to convert kilowatt-hours to milliampere-hours, we first need to look at what these units actually measure. While both relate to energy storage, they measure different physical properties:
- kWh (Kilowatt-hour): A unit of energy representing the amount of work done. One kWh is 1,000 watts of power used for one hour.
- mAh (Milliampere-hour): A unit of electric charge. It represents the amount of current (in milliamps) that can be delivered over one hour.
The Mathematical Formula
Because kWh is energy and mAh is charge, you cannot convert between them without knowing the Voltage (V). The formula is as follows:
(kWh × 1,000,000) / Voltage = mAh
Step-by-Step Conversion Example
Let's say you have a portable power station with a capacity of 1.2 kWh and it operates on a 12V system. How many mAh is that?
- First, convert kWh to Wh by multiplying by 1,000: 1.2 kWh * 1,000 = 1,200 Wh.
- Convert Wh to mAh by multiplying by 1,000 and dividing by voltage: (1,200 * 1,000) / 12V.
- Result: 1,200,000 / 12 = 100,000 mAh.
Why Does Voltage Matter?
Voltage is the "pressure" that pushes the electrical current. A battery with a high voltage can store more energy (kWh) than a battery with the same charge capacity (mAh) but a lower voltage. This is why smartphone batteries are usually rated in mAh (since they almost all operate at 3.7V), while home backup batteries are rated in kWh.
Common Device Voltages
- Smartphone Batteries: 3.7V - 3.85V
- USB Power Banks: 5V (internal cells are 3.7V)
- Car Batteries / Solar Systems: 12V, 24V, or 48V
- Electric Vehicles: 350V - 800V
When to Use This Calculator
This calculator is particularly useful when comparing power banks or solar generators. Marketing materials often mix units to make products seem more powerful. By converting everything to a single unit (like kWh), you can make an "apples-to-apples" comparison of how much energy a device actually holds.