Watt Hours (Wh) to Amp Hours (Ah) Conversion Calculator | Seastar Battery Guide

Watt Hours (Wh) to Amp Hours (Ah) Conversion Formula

Watt-hours (Wh) and amp-hours (Ah) are critical metrics for evaluating battery capacity. Watt-hours measure the total energy a battery can deliver in one hour, while amp-hours gauge the battery’s capacity to maintain a current over time. You can effortlessly convert Wh to Ah using the formula below:

Conversion Formula: Amp Hours (Ah)=Watt Hours (Wh)/Voltage (V)
​Example: If you have a 1200Wh lithium battery with a voltage of 12V, you can calculate the amp-hour capacity as follows: 1200Wh/12V=100Ah

Converting Amp Hours (Ah) to Watt Hours (Wh)

Similarly, you can convert amp-hours back to watt-hours with a simple formula: Watt Hours (Wh)=Amp Hours (Ah)×Voltage (V)

Converting Kilowatt Hours (kWh) to Amp Hours (Ah)

For larger battery systems, such as solar energy storage, you may need to convert kilowatt-hours (kWh) to amp-hours. Since 1 kWh equals 1000 Wh, the conversion formula is as follows:

Capacity (Ah)=Energy (kWh)×1000/Voltage (V)
Example: If you’re building a 10kWh 48V solar energy storage system, calculate the required battery capacity as:10kWh×1000÷48V=208.33Ah

Converting Watt Hours (Wh) to Milliamp Hours (mAh)

For smaller devices like mobile phones, battery capacity is often measured in milliamp-hours (mAh). Since 1 Ah equals 1000 mAh, you can convert Wh to mAh with the following formula:

Capacity (mAh)=Voltage (V)/Energy (Wh)×1000

Example: Suppose your phone’s battery specifications are 3.82V and 10.28Wh. You can calculate the battery capacity as follows:10.28Wh÷3.82V×1000=2691mAh