# Battery Power Question

Discussion in 'Power Electronics' started by magnetman12003, Oct 26, 2012.

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1. ### magnetman12003

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0
Mar 18, 2010
Hi All,

How long should a A23 12 volt battery run if it carrys a 1.3 Watt load?

This is in reference to a "Satellite Generator Magnetic Power" setup shown on the You Tube - over 3,000 hits.

Last edited: Oct 26, 2012
2. ### Harald KappModeratorModerator

12,465
2,987
Nov 17, 2011
The A23 type has a capacity of 225mAh.
A load of 1.3W at 12 V is equivalent to a current of 1.3/12 A = 108 mA
A capacity of 225mAh will last for 225mAh/108mA = 2.08 h

So the battery will be drained after 2 hours.

3. ### magnetman12003

14
0
Mar 18, 2010

I thought the A23 battery has a 55 mAh capacity not 225mAh??

4. ### Harald KappModeratorModerator

12,465
2,987
Nov 17, 2011
I found different data from 55mAh to 225mAh.
If your particular type has 55mAh insert that value into the above equations. 55mAh is 1/4 the capacity of 225mAh therefore the duration wil sink to 1/4*2h=30 minutes.