I opened up one of the 7.2V lithium cmos batteries and found
a diode and if I remember correctly a 33K resistor in series
with the positive lead. The manual for the 286-10MHz that this
was used in specified a 6V cmos battery. The cmos chip is listed
as an MC 146818 AP. I used a 4xAA battery holder to replace the
lithium battery and included a diode and resistor and it has worked
just fine for several years. The diode drop brings the voltage
down to 5.5V or less depending on current draw. I think you should
be OK at 6v. I think most of these cmos chips will maintain data
at 3V or even less.
Mike
On 1999-04-04 [EMAIL PROTECTED] said to [EMAIL PROTECTED]
>Hi, The Compaq DeskPro 286/12 that I have here, the 12.5MHz version
>I have uses a 7.2-volt CMOS backup battery. Compaq advised that
>one probably should not vary the voltage more than about .5 volt to
>either side of the 7.2. This would mean that a 6-volt set-up, as
>in a battery holder that could take four pen light or AA batteries
>would not provide enough voltage to propperly maintain the CMOS
>settings. I heard of the existance of one of those battery holders
>that could take five AA batteries, which would be just about right,
>but I've never been able to locate one. I'm still looking for one,
>by the way.
>Brent Reynolds
>Atlanta, GA USA
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