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How long will a battery run an inverter

I am think of buying a inverter for occasional use of 240v power tools from my leisure battery any idea how long the battery would last.

Asked by: Terry Senior  | 3.11pm, Monday 2 February


WW says:

The time that a battery will run an inverter depends on three things; the capacity of the battery, the wattage of the appliance and the power consumed by the inverter.
The useable capacity of a standard lead acid battery is about half the rated capacity (more can be used but the battery life is shortened), the wattage of the power tool will be marked on it. So for example: if you have a 110Ahr leisure battery this gives a useable capacity of 55Ahr. If you wish to use a 1400W circular saw (you will need a 2000w inverter); dividing 1400W by 12V gives a 116A current draw; adding on a bit to account for the power taken for the conversion by the inverter and it can be seen that you will probably get about 20mins of use from a fully charged battery. Smaller wattage tools such as an electric drill could be used for much longer.

Rupert Smedley  | 9.17PM, Monday 2 February


Readers say:

Thanks very much for your reply. That was very helpful.

Terry Senior  | 1.15AM, Tuesday 3 February

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