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 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?)
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've done it (in a pinch) with the silver defroster grid repair, or silver Printed circuit repair pen to make the contact, backed up with a chunck of appropriately sized shrink tubing to give mechanical strength.. It is NOT robust - but works in a pinch.
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.
The connection tabs on such cells is done with a specialized spot welding machine which avoids excessive heating to the metal which will at the very least shorten the life of the cell, will sometimes kill it entirely, or sometimes yield a nice explosion (especially with lithium I suspect).
I'd order the proper battery, but to tide you over till it shows up, just cut apart the shrink wrap on the old one, and cut the wires as close as you can to the tabs, or actually cut the ears off the tabs. You want bare metal showing on the end of each wire. As best you can, tape them to the new cell from your fridge, making sure to keep polarity correct. Gently put it all back together, and try not to bang things around till the new battery shows up. This is not a high-current application, so as long as it is good metal-to-metal contact, and nothing shorts out, it should work.
Of course, all this only works if you have enough slack in the leads, otherwise you would need to extend them.
I have done home-brew laptop CMOS batteries like that more than once. Some ended up being permanent fixes, since the correct part was not available, or cost more than entire laptop was worth.
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
NOT true on many of the early TPs.. At least one of my old 600s (E or X, cannot remember which) would not boot at all with a dead CMOS battery, and IIRC the T43 would not either. Had to replace the CMOS batteries on a few to get them to boot.
I bought coin cells at the mall, from a "battery store", and they were flat in a matter of days. I'm a little more careful now, where I get stuff. I need to know a shop has a good "turnover of stock", so I won't get screwed again.
If some computer store here carried a pigtailed CR2032, chances are it's been sitting in the shop window for the last twenty years.
The same thing could happen with mail order, unless the seller is big enough that their stock is fresh.
Hmmm. Too bad this is a "web only" item. I guess it would hurt them, to have this in a retail store.
You'll want to check if the IBM's lithium cell is rechargeable or not because you definitely do not want to install a regular lithium cell if the original is rechargeable.
Don't store those lithium cells in the refrigerator because it doesn't help, and it's possible that dew will slowly drain them. The same goes for alkaline cells.
I'd solder a flat strip of springy metal (brass, bronze, steel, but not pure copper) to each wire lead and curve each strip slightly so it will act as a leaf spring. Then attach them to the sides of the cell and wrap the whole thing in heatshrink so those leaf springs will maintain pressure against the cell.
If you decide to solder wires directly to the cell, and I wouldn't try without practicing on something else, like 1" squares cut from a tin can. First tin the wires and the sides of the cell separately. Sand the sides of the cell, wipe with alcohol, apply flux (rosin), and then quickly melt on some 60/40 or 63/37 tin/lead solder to it. Do all this so the solder sticks really well and quickly. Use a 30-40W iron because anything with less power may actually do more heat damage to the cell by not melting the solder as quickly. Then quickly solder the wires to those solder pads. Cover everything with heatshrink.
First VERIFY that the battery is bad. Don't solder on it. Rip the tabs of the existing battery. place them against the new battery, being careful not to short the two sides. Use tape to keep the - from shorting to the plus. Tape the tabs against the battery. Wedge it into the laptop with some foam to keep pressure. Order a proper replacement and install it when you get time.
I have an IBM Thinkpad too, and my battery is also junk. I bought the computer used. It's a T43. The battery was dead days later. There was a warranty, but the company refused to send me the battery, said I had to mail in the computer. Well, first off the cost of mailing was more than a battery, and what about my personal data. No thanks !!!!
I live in a rural area and stuff like this is not sold anywhere nearby. I also refuse to shop ebay ever since they stopped accepting money orders about 3 or 4 years ago. There's no way in hell that I'll give my banking info to Paypal.
Anyhow, I have the same problem. I just leave the computer plugged in all the time. If I take it somewhere, I plug it inot my car inverter. That solved the problem. But I would like to eventually find a means to make a socket for a standard CR2032 battery. But thats a cold weather project.
Oner last comment. I have found that all the IBM computers I have had, including my desktop computer which I am using right now, are well built, but all of them seem to have Bios battery issues. In my desktop puter I have to replace the battery at least twice a year. I dont mind that so much, but having specialty batteries with wires are a major inconvenience and a very stupid design.
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