Kilowatt Hours to Amp Hours (kWh to Ah) Conversion Calculator
kWh × 1,000 / V =
0.00 Ah
Conversion formula: Ah = kWh × 1,000 / V
What Is Kilowatt-Hours?
Kilowatt-Hours (kWh) represents the electrical energy consumed by a device that uses a certain amount of power for one hour.
While kWh is not the SI unit of energy, it is typically used in measurements involving electricity consumption.
What Is an Amp Hour?
Amp-Hours (Ah) is a unit of electrical charge that represents the amount of charge that flows out of a power source for one hour. It is usually used as measure of battery capacity (how much charge a battery can store).
How to Convert Kilowatt-Hours to Ampere-Hours (kWh to Ah Conversion)
Conversion Formula
To fully clarify how to convert kilowatt-hours to amp-hours, we’ll start by diving kWh up into its constituent units.
Kilowatt-hours (kWh) is made up of three units. Of all three, the unit of power – W (watts) – is the only one that is derived.
Watts (W) is the unit of power in the international system of units (SI unit). It can be derived from voltage and current as follows:
W = V x A = VA, where A is electric current and V is voltage.
To convert watts (W) to kilowatts (kW), we’ll divide W (VA) by 1000: kW = VA/1000. Then by substituting VA/1000 for kW in kWh, we’ll arrive at: kWh = VAh/1000.
Next, we divide both sides of kWh = VAh/1000 by V to get Ah/1000 = kWh/V. Then finally, we’ll multiply both sides by 1000 to get our conversion formula:
Ah = 1000 x kWh/V
Going by the formula, to convert kilowatt-hours (kWh) to amps-hours (Ah), divide kilowatt-hours by the voltage then multiply by 1000. This is pretty much what the conversion calculator does for us.
The conversion formula we stated above implies that amp-hours-kilowatt-hours conversions need a value for voltage.
Example: How to Calculate Amp Hours of a Solar Generator
Say we have a solar generator rated 1.5 kWh with a battery voltage of 12 V, and we want to compare it to a 100 Ah solar generator.
We’ll start by converting kilowatt-hours to ampere-hour: Capacity in Ah = (1000 x 1.5)/12 = 125 Ah.
After that, we’ll compare the capacities.
Of course, the 125 Ah generator has a higher capacity than the 100 Ah generator. In other words, it will store more electrical charge and can power devices longer.
Why Convert Kilowatt Hours to Amp Hours (kWh to Ah)?
We may have to convert kilowatt-hours to amp-hours when estimating the capacity of a battery bank that will meet our energy requirements. Typically, electrical energy is measured in kWh. Battery capacity, on the other hand, is usually measured in Ah.
For us to estimate the energy equal to the capacity of the batteries, we’ll have to convert to amp-hours. We may also choose to convert amp-hours to watt-hours or kilowatt-hours for the estimation.
Charge rate, charge current, and discharge rate are some other reasons to do an ampere-hours (Ah) kilowatt-hours (kWh) conversion.
For instance, ideal charge current is typically around 10-25% of the capacity of the battery in Ah. If the capacity of the batteries is not in Ah, we’ll have to do an Ah conversion before we figure out the charge current. Of course, this conversion could be kilowatt-hour to amps-hours (kWh to Ah).
Once we know our batteries’ charge current, we can limit the charge current from our solar panels through the charge controller.
Kilowatt Hours to Amp Hours Conversion Chart
As said earlier, to calculate Ah from kWh, volts should be provided. So, in creating these charts, we chose two common battery voltages 12v and 24v.
For a 12v battery:
kWh | Ah |
0.1 | 8.34 |
0.5 | 41.67 |
1 | 83.3 |
5 | 416.67 |
10 | 833.33 |
50 | 4166.67 |
100 | 8333.33 |
kWh | Ah |
0.1 | 4.17 |
0.5 | 20.83 |
1 | 41.67 |
5 | 208.33 |
10 | 416.67 |
50 | 2083.33 |
100 | 4166.67 |
The Difference Between Ampere and Ampere Hours
Ampere and Ampere-hours are measures of electrical charge. However, they are pretty different.
Ampere (A) is the rate at which electrons/charge move through an electrical conductor. As such, an ampere represents 1 coulomb of charge traveling through a point in a conductor every second.
On the other hand, amp-hours (Ah) is the amount of charge that moves out of a power source (typically a battery) in 1 h. One Ah means that a power source discharges a current of 1 amp every 1 h.