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Adapting cell battery to HP 41
02-25-2019, 03:31 PM
Post: #1
Artur - Brasil Offline
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 		Posts: 163
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Adapting cell battery to HP 41
Hi, guys!

Last week I concluded my plans to adapt a cell phone battery to my HP-41.

Using just a small 850mAh battery, one small charger board, another small step-up board and it's done!!!

The circuits themselves use only 85nA;
The HP in standby mode I think something around 1mA.

So, I believe 850mAh/1.085mA --> 780 h --> 30 days in standby mode!

Red - charging
Blue - charged.


   
   
   
   
   
ARTUR MARIO JUNIOR
BRAZIL
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Messages In This Thread
Adapting cell battery to HP 41 - Artur - Brasil - 02-25-2019 03:31 PM
RE: Adapting cell battery to HP 41 - cruff - 02-26-2019, 12:45 PM



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