What is the capacity of a battery?
What is battery capacity? |
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Battery capacity refers to the amount of electrical charge a battery can hold.
The larger the battery’s capacity, the longer it can run before needing to be recharged. |
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Amp hours |
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Battery capacity is measured in amp hours. Each battery is given an amp hour rating which is written as a number followed by the letters ‘AH’ or ‘Ah’. | |||
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This number tells you how many amps of electrical charge the battery can deliver for the duration of 1 hour.
Typically, for cordless screwdrivers, battery capacity ranges from 1.1 AH to 2.0 AH. |
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You can work out how many amps are being used by looking at the tool’s battery voltage and capacity.
For example, the cordless screwdriver on the left has a 4 volt battery with an amp hour rating of 1.5 AH.This means it can deliver an electrical charge of 1.5 amps for the duration of 1 hour, or 3 amps for 30 minutes, or 6 amps for 15 minutes and so on… |
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If the tool runs for 15 minutes at full power before the battery runs out, then we know that at full power, it’s using 6 amps. |
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Capacity summary |
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A battery with a higher Ah rating has a larger capacity and will run for longer between charges compared to a smaller capacity battery doing the same task. | |||
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However, a tool with a larger battery capacity is likely to be more expensive. | |||
