Thinkpads Forum

[Moderator edit: thread moved from Legacy Hardware forum]

Why did/do all computer makers insist on soldering CMOS batteries to the MB? I guess I can see the button batteries to conserve space on laptops but on desktops why not AA alkalines in a holder? Was there any good reason for the soldered batteries except to annoy me?

I don't know the answer to this. I do know that in the 770 series, the CMOS battery is a standard, removable CR2025 in a plastic holder and in the 600 series, the CMOS battery is the same thing but plastic wrapped, also replaceable. I'm pretty sure that there are no Thinkpads built after that period (1998) that have the CMOS battery soldered to their motherboards.

It would be interesting to know which early model Thinkpads have the batteries soldered onto their boards...that sure would make it hard to replace them!!

Phil.

Phil, he meant soldered cmos batteries on desktop motherboards in which case this topic should have been posted in another forum.

All the Pentium era desktop motherboards I've handled so far did not have soldered cmos batteries on the motherboard. The cmos batteries are CR2032 coin types held mechanically in place by a holder/connector. I've seen and changed soldered cmos batteries (usually nicads) on the old 486 motherboards.

The current requirement of the cmos is so little that a coin lithium cell can supply the demand till (practically) near to its shelf life so there is no need to use larger AA sizes. Alkalines, aside from being bulkier for the same capacity, have significantly shorter shelf lives, and IMHO never been used.

Actually, I was referring to both as a general rant. I know most TP's have holders a nd are fairly accessable but I guess my real question is "Why not standard AAA bateries"? or some type of standard either on laptops or desktops so there doesn't have to be a gazillion different setups. Sorry if this didn't belong here but I was in the process of changing the cmos battery in my 365XD and this topic crossed my mind as I looked over my button battery inventory and discovered I had 25 different types alone and I know many I don't have.
Thanks for reading.
NOYK

nooneyouknow wrote:"Why not standard AAA bateries"?

Taking a guess and saying it's probably shelf life and physical size that makes a single coin-type lithium battery preferable over two AAA batteries (3V needed for backup). I believe some of the older motherboards may have used two (or three?) button batteries of silver-oxide construction (1.5V each, like AAAs).

nooneyouknow wrote:...or some type of standard either on laptops or desktops so there doesn't have to be a gazillion different setups.

Here is where I would ask the same thing. I just found out recently that some of the older TPs (newer ones too?) had CMOS batteries which did NOT come with leads already attached. In other words, something you could probably replace with a battery from a well-stocked 7-11. Perhaps it's the designed-in, planned obsolescence thinking that makes manufacturers use the lowest cost solution (at the time), without any thought as to the price and availability 7 to 10 years down the line when the battery dies.

I got the coin cell battery for my 365x at Radio Shack... wasn't a problem.