Battery Amp hours To Watts (Ah to Watts) Calculator

Use our battery amp-hour (Ah) to watts calculator to find out the battery capacity in watt-hours.

battery Ah to watts calculator

Battery Capacity (Amp-hours)
Battery Volts

How to use this calculator?

  • Enter the capacity of your battery in amp-hours (Ah).
  • Enter the voltage of your battery (12,24,48v).
  • Click on the "CALCULATE" button to get the result.

Video - Explained Volts, Amps, & Watts

How to calculate watts in a battery?

Watts is the unit that represents the total number of power. So to calculate watts from Ah use this formula.

Watts = Amps*volts 

Multiplying the value of amps with volts will give you the number of watts.

For Example

Let's suppose you have a 12v 300Ah battery.

12v * 300Ah = 3600 watts 

12v 300Ah battery is equal to 3600 watts or 3.6kW.

How many watts is a 12-volt battery - Chart

Here's a chart with the conversion of different size 12v batteries in watts.

12V Battery Size (Ah)Equal to Watts (W)
7Ah84 watts
12Ah144 watts
33Ah396 watts
50Ah600 watts
60Ah720 watts
70Ah840 watts
100Ah1200 watts
110Ah1320 watts
120Ah1440 watts
150Ah1800 watts
160Ah1920 watts
170Ah2040 watts
200Ah2400 watts
220Ah2640 watts
250Ah3000 watts
300Ah3600 watts
400Ah4800 watts
Table: how many watts in a 12v battery


  • 12v 7Ah battery is equal to 84 watts.
  • 12v 12Ah battery is equal to 144 watts.
  • 12v 100Ah battery is equal to 1200 watts or 1.2kW.
  • 12v 200Ah battery is equal to 2400 watts or 2.4kW.

Why calculate watts in a 12v battery?

Battery capacities are rated as Amp-hours (Ah). But most of our appliances are rated as watts.

So calculating Ah to watts will give you an idea of the total capacity of your battery in watts so you can determine how long will your battery last on running any appliances.

And also what appliances running your battery will fall in the safe zone because of battery c-ratings (Charge and discharge rate of battery).

To better understand this, read the article Maximum Charging Current & Voltage For 12v Battery.

And also converting your 12v battery in watts will give you an idea of how many watts it can store so you can pick the right size solar panel in order to recharge your battery.

Related post: How Long To Charge 12v Battery With Solar panel

How many watts is a 12V car battery

Usually, 12v car batteries have a capacity of 60Ah so let's assume that you have a 12v 60Ah car battery. 12 × 60 = 720 watts. So a 12v car battery is equal to 720 watts.

You can calculate the value by yourself with the formula which I have mentioned above or by using a calculator.

How many watt-hours in a car battery 12v 100Ah car battery has 1200 watt-hours (Wh).

How many watts are in 12 volts

To calculate how many watts are 12 volts, you would need the value of amps, and multiplying the amps by 12 will give you watts (Watts = Amps × 12).

For example 12v 33Ah how many watts? 12 × 33 = 396 watts.

How many watts are in a 12-volt deep cycle battery

12V 150Ah deep cycle battery has 1800 watts or 1.8kW (watts = Amps × volts).

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Chris Tsitouris is a renewable energy professional with 10+ years of experience as Director of Engineering at Solar Spectrum, previously working as Project Manager at SunPower and Energy Analyst at the National Renewable Energy Laboratory. As a thought leader, Chris has authored numerous articles and research papers.

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