On a similar point, we are evaluating batteries from different
     manufacturers as the moment for a battery powered application.

     And we are discharging Ni-MH batteries down to 1.1V per cell, and seem
     to be getting aound 80% capacity out of the cell when discharging at
     1C ... does that sound reasonable?

     For Ni-MH what volatge per cell do the manufacturers rate the mAh
     capacity of the battery. or is this one of the tricks they play with
     specs to make thier batteries look batter than the competition?

     Does dicscharge rate affect the capacity of the battery to any great
     extent?

     thanks in advance,
     SW.


______________________________ Reply Separator _________________________________
Subject: Re: selection of battery for power consumption of 300mA/hour
Author:  pic microcontroller discussion list <PICLIST@MITVMA.MIT.EDU> at
INTERNET
Date:    09/06/98 14:57


At 02:41 PM 8/06/98 -0700, you wrote:
>http://www.duracellnpt.com/techref.d/refind.html
>
>Has some specs on duracell batteries. Note that in practice what you get
>is about 75% of the rating. Also note that they expect you to take the
>cells down to something like .8 volts
>
>Cheers,
>Bob
>
>

I don't agree with the 75% of capacity, we get 100 to 115% consistntly, note
that the capacity tests are done with a light load! Not a huge 1AMP  or
something like that. 0.8V is quite OK for most things, also note the
internal impedance of the cell at this voltage.

Dennis

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Dennis Plunkett: Embedded Hardware, Software design
NEC Australia DRMASS
ph 03 9264-3867

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