# Battery question
**URL:** https://community.electricforum.com/t/battery-question/715
**Category:** EV Small Talk
**Created:** [June 5, 2008, 10:26am UTC](https://community.electricforum.com/t/battery-question/715 "2008-06-05T10:26:18Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Paul51480](https://community.electricforum.com/u/Paul51480)
#### Post date: [June 5, 2008, 10:26am UTC](https://community.electricforum.com/t/battery-question/715/1 "2008-06-05T10:26:18Z")
Is it possible to get 12v 10 amp out of a 3.2v 40 amp cell ?
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### Author:  [@frodus](https://community.electricforum.com/u/frodus)
#### Post date: [June 5, 2008, 10:48am UTC](https://community.electricforum.com/t/battery-question/715/2 "2008-06-05T10:48:54Z")
calculate power:
12\*10 is 120W
3.2\*40 =128W
If you could find (or build) a DC-DC step up converter for a 3.2V battery, and step up to 12V, but it would have to be 94% efficient. Not impossible, but in order to keep the power you want of 120W, you’d need 120W of the 128W available from the 3.2V cell to go to the output.
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### Author:  [@Paul51480](https://community.electricforum.com/u/Paul51480)
#### Post date: [June 5, 2008, 11:22am UTC](https://community.electricforum.com/t/battery-question/715/3 "2008-06-05T11:22:06Z")
Thnx I’ll have to look around for a converter…