Does your mainboard also have the DS1287 (black block with white clock) or maybe an extra battery (blue/green cylinder on board or black plastic box connected to it by a 4-pin)? The latter would be much easier to replace.

If you have a DS1287, you can solder a battery holder on it like this

Yeah! It's a DS1287 with no extra battery elsewhere on the board! Thanks for the guide!

Have fun 'opening' the piggypack 😉

Thanks

Do you live near a Fry's Electronics? They normally carry a few Dallas 12887's in stock per store. In many cases, the Dallas RTC is socketed, making it easy to replace. If it's soldered, it's tougher because of the amount of pins, but not impossible with a little patience, a good soldering iron, and a good solder-sucker and wick.

I have a Pentium Motherboard that uses the 12887. At one point, I had to replace it, and it was much easier than everyone made seem.

Let me take a look at some of my component catalogs too... I may be able to find a current mail-order SKU for you.

I live in Europe. I didn't try searching for the DS1287 on eBay. Where I am at the moment it's very difficult to even find a 3V coin battery. 🙁 I think I'll delay that when I go back home.
At soldering I'm a disaster and I don't even have the right solderer so I guess if I find a DS1287 I'll bring the 'patient' home with me and have my friend de-solder and solder the new one.
That would be the most preferable solution for me because I would like my old 286 to look like it was.
Thanks for the tips.

On the other hand.... how long would a DS1287 battery last considering that computer would stay turned off for months?

Totally nonvolatile with over 10 years of operation in
the absence of power

from their datasheet

What about these ones?

http://anonym.to/http://cgi.ebay.it/MODULI-DI … VQQcmdZViewItem

I'll have my friends buying them for me, then possibly desoldering the old one and soldering the new one

I had a look at the pictures and thought "What a ugly hack". Instead of molesting the chip like that I would try to find a pair of very very thin wires that I could wrap 5-6 times tightly around the pins. When the chip is put back in the socket, I would hope the wires would still be safely connected. Then the battery can safely be placed somewhere nearby.

@MiniMax:
The pins you need don't stick out at the bottom. They are connected to a little battery in the block above the chip. Thus you have to 'open' the block...

@butterfly: It should not have been lying around for years (I didn't bother to read that overcrowded ebay site)

h-a-l-9000 wrote:

It should not have been lying around for years (I didn't bother to read that overcrowded ebay site)

"It" being my old 286? Years ago my mother imposed me to make that "ugly thing" disappear, so I arranged to bring it to our house in the countryside. The battery discharged 'cos the computer is not very much on, that is only when I go there and use it mainly like a big fat retrogaming and sometimes retrocomputing console

'It' being the chip you want to buy. They might have pulled it from some old pentium board.