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Thread ID: 31201 2003-03-14 23:58:00 CMOS Battery Miami Steve (2128) Press F1
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128232 2003-03-14 23:58:00 My spare PC (a PC Direct Discovery 545 - 120MHz Pentium) tells me the CMOS battery is flat. However, when I open the case and look for the battery, expecting a disc type battery, I can only find a 2 inch long block of black plastic which is plugged into the MOBO and says it is a 3.6V High Energy Lithium battery. Is this the CMOS battery? How do I replace it? Can I buy a new one of the same type somewhere, or do I ned to do something to convert to a disc battery.

TIA
Miami
Miami Steve (2128)
128233 2003-03-15 00:36:00 That will be the COSMOS battery. Suggest that you plug the comp in to the mains - does not need turning on - and see if it re-charges OK.
Bye
Peter H (220)
128234 2003-03-15 00:41:00 I'll give that a go Peter H. The PC is normally switched off at the wall, so that could very well be the problem.

Thanks for your reply...

Cheers
Miami
Miami Steve (2128)
128235 2003-03-15 01:24:00 That battery is a lithium one. It is not rechargable. Replacements are available, but they are very expensive.

A cheap fix is to get a 3-cell AA holder and use three alkalines (or even ordinary AA cells --- you get shelf-life). You can find a holder (closed type) with wires fitted at DSE, and you can twist and tape the joints to the wires on the plug of the original if you haven't got soldering kit..
Graham L (2)
128236 2003-03-15 03:53:00 Lithium are not that dear. Jaycar in Auckland, have a large range from $17.00 to $20.00. That is for 3.6v packs. Suggest that you take your one in and see if one is suitable. Saves a lot of messing around with new holders etc.
Bye
Peter H (220)
128237 2003-03-15 04:42:00 I had a similar problem with another PC Direct computer (except it was 3v). I simply got 2 AA battery holders, and did a bit of soldering to connect them to provide 3v. I then used velcro to stick it to the case.

You could use 3 1.2v AA batteries (eg. Nicad rechargables - if you have old ones lying around somewhere) and use a similar setup to what I did.
somebody (208)
128238 2003-03-15 06:59:00 remember that cmos/bios batterys are between 3-15v and you HAVE to make sure the voltage/ampage is the SAME as the one you want to replace. Get this worng and "stuff" will happen, and it might not be nice.

:-)
minos (3185)
128239 2003-03-15 07:07:00 CMOS backup batteries have such a low drain on them that "amperage" as in the last post suggestion is not relevant in this application.

Only relevance is the voltage. AA cells are "nominal" 1.5 volts but new and with no load are around 1.65 volts each.
godfather (25)
128240 2003-03-15 10:13:00 Hi, Very interested on the cmos battery postings as I was about to replace mine because of a problem I have however now I see that it obviously can't keep its charge if the computer is switched off at the wall (as I have been doing ). How come Graham L reckons the lithium battery can't be charged? BobM (1138)
128241 2003-03-15 10:17:00 He is right!!!

Just my humble opinion.
Elephant (599)
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