IBM thinkpad memory

[stardust]

I bought a second user IBM thinkpad, which is great, except the system memory isn't holding date/time settings.  I am guessing that it needs a new battery given the age of the machine.  where do I find hte instructions to find out what size battery and how to change it?

[vikingken]

Changing the battery on any laptop isnt as straight forward as a desktop. You can quite easily do some maintenance on a modern laptop, but changing the BIOS battery isn't included. Every make and model is a bit different and I couldn't even tell you where to start without looking it up. Unless you know what you are doing, leave it to someone who does. I do agree with your diagnosis though, it sounds like the battery has gone for a ball of chalk.

[mikkh]

Thinkpad is a huge range with hundreds of different models, some help in narrowing yours down might pinpoint if it's possible or not. Like Ken says, nothing is standard in laptops and it may even be soldered in place and almost impossible to change without a soldering iron and a good deal of electronics knowledge. On the other hand it may be simple like a desktop PC

[johnnybee]

First thing to do, Bee, is to ascertain the model and serial numbers of the machine; if you then go onto the IBM site you can use their search engine to find a download for the Users' Manual.
That will then tell you (a) where the BIOS battery is, and (b) if it IS changeable, how to do it.
It's the only way to go, pet; remember, "if in danger, if in doubt, get the bloody manual out"!

[vikingken]

Dont time fly, it was 2005 when Lenovo group took over from IBM. Over 5 or 6 years old, laptops start getting tricky to fix. Its cheaper to by a cheap new one than to try and fix up these old ones, unless your sure you can do it yourself. Laptops were always kept in house, they didn't build them for anyone to fix. I suspect thats why the last owner sold it, they were very good machines in their day. That day has long gone though. If your not in any hurry you can always correct the time and date after booting, you wont get online if its wrong though.

[johnnybee]

Just a thought here, Ken; if the main battery is OK, or if the charger is kept switched on, does that automatically keep the 3v circuit on the 'board live as well?
I guess they vary by make and model, but I think I remember that old Dell Latitude had the same problem; as long as the battery was charged and/or the charger was on, the BIOS would remain as set.
If you disconnected the main battery, the BIOS settings would revert to default.
Maybe that's worth a try, just to see what the score is?

[vikingken]

I know what you mean John, but I'm not sure about Laptop motherboards. I've got motherboards that stay live after shutdown, unless the power from the wall is turned off. Once the power goes right off, if returned the board doesn't power up again. I thought turning a laptop off, preserved the battery. A lot of people just shut the lid and let the computer sleep. Handy for some, but it is still draining some of the life out of the battery. Shutting down is supposed to fully preserve whatever life the battery has got in it. The charger being plugged in might make a difference, but I wouldn't bet money on it. A laptop will run on the mains without a battery, so the charger isnt just a battery connection alone. Things start to get complicated at that point and I haven't made the laptop my lifes work.

[johnnybee]

Fair enough, Ken - I just had the thought that while to battery is still connected and live, there might be a constant 3v feed onto the MB to keep the CMOS chip happy, even when the rig is powered down.
I's only 0.4 mA anyway, so it would take weeks to drain the battery on most lappys I've come across.

[stardust]

TBH it's no problem to set the date each time I startup and it will be packed away for a few months soon.
It does seem to have some residual backup power as a short disconnection from the mains supply does not seem to affect it.
For what it cost it is doing the job.