How to Convert Amp Hours to Watt Hours?

How to Convert Amp Hours to Watt Hours?

Converting amp-hours (Ah) to watt-hours (Wh) involves multiplying the amp-hour rating of a battery by its voltage. This conversion is important because it helps determine the total energy capacity of a battery in terms of watt-hours, which is a more universal unit for measuring energy.

How to Convert Amp Hours to Watt Hours?

What is a Watt-Hour?

A watt-hour is a unit of measurement used to quantify the amount of electrical energy consumed or produced over a certain period of time. It represents the amount of power consumed or produced in one hour at a rate of one watt. This measurement is commonly used to assess the energy consumption of electrical devices or systems and is essential for understanding electricity usage and billing.

What is an Amp-Hour?

An amp-hour (Ah) is a unit of electrical charge commonly used to measure the capacity of a battery. It represents the amount of electric charge transferred by a current of one ampere flowing for one hour. In simpler terms, it indicates the amount of electrical energy a battery can store and deliver over a specific period of time. Amp-hours are frequently used to express the capacity of batteries, particularly in applications such as electric vehicles, solar power systems, and portable electronic devices.

How Do You Convert Amp Hours to Watt Hours?

To convert amp-hours (Ah) to watt-hours (Wh), you need to multiply the voltage (V) by the amp-hour rating (Ah). The formula for this conversion is:

Watt-hours (Wh)=Amp-hours (Ah)×Voltage (V) 

This formula is derived from the basic equation for electrical power, which states:

Power (P)=Voltage (V)×Current (I) 

Given that current (I) is equivalent to amperage (A), and power (P) is measured in watts (W), the unit for energy (Wh) is obtained by multiplying the current (Ah) by the voltage (V).

For example, if you have a 12-volt battery with a capacity of 100 amp-hours, the watt-hour rating would be:

Wh=100 Ah×12 V=1200 Wh 

So, the battery has a total energy capacity of 1200 watt-hours.

Convert Amp Hours to Watt Hours

How Many Watt Hours in a 100 Ah Lithium Battery?

To determine the watt-hour (Wh) rating of a 100 amp-hour (Ah) lithium battery, you need to know the voltage of the battery. Lithium batteries typically have a nominal voltage of around 3.7 volts per cell, but this can vary depending on the specific chemistry and design of the battery.

Assuming a nominal voltage of 3.7 volts per cell, for a single lithium cell:

Wh=100 Ah×3.7 V=370 Wh

So, a single lithium cell with a capacity of 100 amp-hours has a watt-hour rating of 370 watt-hours.

However, lithium batteries used in practical applications are often made up of multiple cells connected in series to increase voltage. For example, a 12-volt lithium battery might consist of 3 cells in series, resulting in a total voltage of 12 volts.

In this case, the watt-hour rating of the 100 amp-hour lithium battery would be:

Wh=100 Ah×12 V=1200 Wh

So, a 100 Ah lithium battery with a total voltage of 12 volts would have a watt-hour rating of 1200 watt-hours.

Where is an Ah to Wh Conversion Chart?

You can find amp-hour (Ah) to watt-hour (Wh) conversion charts online from various sources, including battery manufacturers, electrical engineering websites, and energy-related forums. These charts typically provide conversion factors based on the voltage of the battery.

Alternatively, you can calculate watt-hours from amp-hours using the formula:



  • Wh is the watt-hour rating,
  • Ah is the amp-hour rating, and
  • V is the voltage of the battery.

This formula allows you to calculate the watt-hour rating of a battery based on its amp-hour capacity and voltage, which you can then use for your specific application or project.

Amp Hours to Watt Hours Conversion Charts

Amp-Hours Watt-Hours at 12V Watt-Hours at 24V Watt-Hours at 36V Watt-Hours at 48V
50 Ah 600 Wh 1200 Wh 1800 Wh 2400 Wh
100 Ah 1200 Wh 2400 Wh 3600 Wh 4800 Wh
150 Ah 1800 Wh 3600 Wh 5400 Wh 7200 Wh
200 Ah 2400 Wh 4800 Wh 7200 Wh 9600 Wh
250 Ah 3000 Wh 6000 Wh 9000 Wh 12000 Wh
300 Ah 3600 Wh 7200 Wh 10800 Wh 14400 Wh
350 Ah 4200 Wh 8400 Wh 12600 Wh 16800 Wh
400 Ah 4800 Wh 9600 Wh 14400 Wh 19200 Wh
450 Ah 5400 Wh 10800 Wh 16200 Wh 21600 Wh
500 Ah 6000 Wh 12000 Wh 18000 Wh 24000 Wh
550 Ah 6600 Wh 13200 Wh 19800 Wh 26400 Wh
600 Ah 7200 Wh 14400 Wh 21600 Wh 28800 Wh
650 Ah 7800 Wh 15600 Wh 23400 Wh 31200 Wh
700 Ah 8400 Wh 16800 Wh 25200 Wh 33600 Wh
750 Ah 9000 Wh 18000 Wh 27000 Wh 36000 Wh
800 Ah 9600 Wh 19200 Wh 28800 Wh 38400 Wh
850 Ah 10200 Wh 20400 Wh 30600 Wh 40800 Wh
900 Ah 10800 Wh 21600 Wh 32400 Wh 43200 Wh
950 Ah 11400 Wh 22800 Wh 34200 Wh 45600 Wh
1000 Ah 12000 Wh 24000 Wh 36000 Wh 48000 Wh

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