Convert Watt Hours (Wh) to Amp Hours (Ah) and Vice Versa
When it comes to understanding the energy capacity of a battery, the Amp-Hours (Ah) and Watt-Hours (Wh) measurements are both important. While Ah measures the current capacity of a battery, Wh measures the total amount of energy that can be delivered by the battery. In this blog post, we will explain the Amp-Hours (Ah) to Watt-Hours (Wh) conversion, including the formulas and practical applications.
Formula for Conversion
The formula for converting Amp-Hours (Ah) to Watt-Hours (Wh) is straightforward:
Wh = Ah x V
where V is the voltage of the battery. For example, a 12-volt battery with a capacity of 100 Ah would have a total energy capacity of 1200 Wh (100 Ah x 12 V = 1200 Wh).
While the formula is simple, it is important to note that the voltage of a battery can vary over its discharge cycle, which can affect the accuracy of the calculation. In some cases, it may be necessary to measure the voltage at different points in the discharge cycle to get a more accurate estimate of the total energy capacity.
Practical Applications
Understanding the Ah to Wh conversion is important for a variety of practical applications, especially when it comes to choosing the right battery for your needs. For example, if you are using a battery-powered device that requires a certain amount of energy to operate, knowing the total Wh capacity of the battery can help you determine how long the battery will last before it needs to be recharged or replaced.
Similarly, if you are comparing two batteries with different Ah ratings and voltages, calculating the Wh capacity of each battery can help you make an apples-to-apples comparison of the total energy capacity. This is especially important if you are comparing batteries with different chemistries, such as lead-acid and lithium-ion, which can have different voltage characteristics.
Converting Watt Hours to Amp Hours
These handy conversion charts show how to convert watt hours (Wh) to amp hours (Ah) at various DC voltages, helping you to design battery systems with the appropriate capacity.
- Watt Hours to Amp Hours at 12V
- To convert 100 Wh to Ah at 12V, divide the watt hours by the voltage (12V): 100 Wh / 12V = 8.33 Ah
- To convert 200 Wh to Ah at 12V, divide the watt hours by the voltage (12V): 200 Wh / 12V = 16.67 Ah
- To convert 500 Wh to Ah at 12V, divide the watt hours by the voltage (12V): 500 Wh / 12V = 41.67 Ah
- Watt Hours to Amp Hours at 24V
- To convert 100 Wh to Ah at 24V, divide the watt hours by the voltage (24V): 100 Wh / 24V = 4.17 Ah
- To convert 200 Wh to Ah at 24V, divide the watt hours by the voltage (24V): 200 Wh / 24V = 8.33 Ah
- To convert 500 Wh to Ah at 24V, divide the watt hours by the voltage (24V): 500 Wh / 24V = 20.83 Ah
- Watt Hours to Amp Hours at 48V
- To convert 100 Wh to Ah at 48V, divide the watt hours by the voltage (48V): 100 Wh / 48V = 2.08 Ah
- To convert 200 Wh to Ah at 48V, divide the watt hours by the voltage (48V): 200 Wh / 48V = 4.17 Ah
- To convert 500 Wh to Ah at 48V, divide the watt hours by the voltage (48V): 500 Wh / 48V = 10.42 Ah
| Watt Hours | 6V | 12V | 24V | 36V | 48V | 60V |
|---|---|---|---|---|---|---|
| 50 Wh | 8.33 Ah | 4.17 Ah | 2.08 Ah | 1.39 Ah | 1.04 Ah | 0.83 Ah |
| 100 Wh | 16.67 Ah | 8.33 Ah | 4.17 Ah | 2.78 Ah | 2.08 Ah | 1.67 Ah |
| 200 Wh | 33.33 Ah | 16.67 Ah | 8.33 Ah | 5.56 Ah | 4.17 Ah | 3.33 Ah |
| 500 Wh | 83.33 Ah | 41.67 Ah | 20.83 Ah | 13.89 Ah | 10.42 Ah | 8.33 Ah |
| 1000 Wh | 166.67 Ah | 83.33 Ah | 41.67 Ah | 27.78 Ah | 20.83 Ah | 16.67 Ah |
| 2000 Wh | 333.33 Ah | 166.67 Ah | 83.33 Ah | 55.56 Ah | 41.67 Ah | 33.33 Ah |