On Sat, 23 Jul 2011 16:11:53 -0400, Paul <nospam@needed.com> wrote:

>micky wrote:
>> On Sat, 23 Jul 2011 14:52:40 -0400, micky <NONONOmisc07@bigfoot.com>
>> wrote:
>>
>>> It seems my IBM Thinkpad's CMOS battery has died, and it's know that
>>> it won't boot wihtout it.
>>>
>>> I don't have time to wait for a new one by mail, plus I have some
>>> CR2032's in my fridge. The flat things that look like litttle
>>> frisbees.
>>>
>>> The current one has the wires connected to metal tabs stuck (welded?)
>>> to the battery on both sides. Is there a way I can do this without
>>> exploding or otherwise ruining the battery???????
>>
>> I didn't think solderign would work, but it occurs to me that
>> somewhere I have a mini torch, with one or two little tanks of gas, 2
>> or 3" tall, that is supposed to get very hot at a small place. Maybe
>> I could solder the wires to the battery with that???
>>
>>
>>> I see that Radio Shack has a clip that holds such a battery but I
>>> think it's too thick to fit. I just tore apart a 16 year old
>>> computetr to get it's battery holder, but it was defintiely too thick
>>> (Does anyone want a kit to make a 16 year-old computer?)
>>>
>>> Thanks.
>>
>
>They use spot welds for a reason. A spot welder wouldn't
>do nearly as much thermal damage to the CR2032 as soldering would.
>It would probably ruin whatever functions as a separator between
>the two halves of the battery.
>
>None of the datasheets I've downloaded for CR2032, list short
>term temperature as a parameter (like whether it could support
>a solder profile). The max operating temp is listed as 60C or
>70C, which isn't nearly enough for soldering, even with low
>temp alloys. And the cell surface could be stainless, meaning
>you'd need a solder that "sticks" to that stuff. If the solder
>had a bit of silver added to it, that would probably push
>the melt point too high.
>
>You could think a bit more creatively than that. For example, how many
>"holes or storage spaces" are currently available or unused on the unit.
>Perhaps you can craft a 3V source, using a couple regular dry cells.
>At Radio Shack, I could pick up a two cell holder, two dry cells
>(1.5V each), then use the wire on the existing dead CR2032 assembly,
>and solder that wire to the tabs on the plastic battery holder. It's
>just a matter of routing the wire inside the laptop, using any
>available holes. The battery pack would hold you over until the
>new CR2032 assembly comes in the mail.
>
>You could build a regulated circuit to run off the main battery,
>but then, if left that way, you could dangerously discharge the
>main battery. Some battery chargers will not charge a laptop
>battery, if the battery ever heads below a certain threshold.
>
>I think it's slightly safer, to just build a battery source
>using dry cells.
>
>Have you ever tried to find a 3.0V output three terminal regulator
>in town ? That is probably a mail order item as well, and will
>take just as long to get here, as the pigtailed CR2032 will.
>The battery holder and dry cells, I can think of two stores in
>town that can provide them for me.
>
> Paul
There are a LOT of sources for the lithium button cells with wires
attached - with the wrong plug ends on them - in most major centers.
Most electronics supply shops or pattery specialists will have one you
can cobble the correct wire end onto