Incorrect Charge Level Displayed for "Replacement" Battery

[JClarkW]

I have an old *IBM* Thinkpad A22p. My main battery failed some time ago (I still have a secondary battery for the 'Ultrabay'), and branded replacements have apparently been unavailable for some years. Therefore I purchased a generic "replacement" battery (I think it was from Batteries Plus) that both operates and recharges in the computer successfully.

The problem is that most of the time the battery's state of charge is incorrectly reported, at first by the factory-original Thinkpad 'battery miser' software under W2K and now, after a bare-metal upgrade to Windows XP SP3 with no Thinkpad software re-installed, by Windows itself. (If I unplug and re-plug the charger, usually the battery state is correctly indicated for a while.) Therefore I suspect some sort of hardware incompatibility between the new battery and the A22p hardware that senses battery state.

Questions:
1) Is there anything I can do to get this off-brand battery to function correctly?
2) Are there any other off-brand batteries that will function correctly?
3) Is there source of genuine (possibly refurbished) Thinkpad replacement batteries for this machine? (Unfortunately I seem to have thrown away the old dead one, so refurbishing that is not an option.)

Thanks for any information on this. -- JClarkW

[JClarkW]

Update to above: The guys at Batteries Plus claim that I can correct this problem simply by making sure I have a good backup battery (I just bought from them, since the existing one is 10 years old) and then updating the system BIOS (which is currently at the latest version, 1.11, for my model 2629-UTU) WITH THEIR REPLACEMENT BATTERY INSTALLED. I'm pretty sure that the latter step has not been done, since I updated the BIOS long ago.

More Questions:
4) Is there any truth to the above claim? (I don't want to mess with the BIOS unnecessarily!)
5) Does the battery itself have updatable firmware (perhaps the "embedded controller" that's part of the BIOS -- also currently at the latest version 1.07)?
6) What does the backup battery do besides maintain the date and time while the main battery is uninstalled (or dead)?

[RealBlackStuff]

Nothing works better than an official IBM or Lenovo battery.
Almost any knock-off replacement is going to cause problems sooner or later.
The claim that a backup battery influences a main battery is a load of BS.
Although in some older laptops you do need a good working CMOS battery (as they are called).
And all they do is keep the date/time and some BIOS settings.
With a bad/dead CMOS battery the machine will automatically revert to BIOS defaults and you only need to set date/time every boot.

Under XP you can install Power Management and Battery Maximiser software, that can recalibrate the battery gauge.
If you do that (once or maybe twice) the charge indicator might become correct, but I wouldn't count on it, because it is not an original battery.
Batteries have no firmware that can be changed/updated.

[JClarkW]

Thanks much, again, for the straight story! I'll give up on this wild goose chase and just live with it... -- JClarkW

[JClarkW]

...Under XP you can install Power Management and Battery Maximiser software, that can recalibrate the battery gauge...

One follow-up if I may: As I recall, even on this old A22p the ThinkPad power management suite showed not only the state of charge (whatever that really means) but also the battery voltage and the charging or discharging current. This information made it very clear when the machine was going to power down -- somewhere around 10.9 V as I recall -- so it's not surprising that Thinkpad software can "re-calibrate" its battery gauge.

But Windows XP's native power management seems to be able to recalibrate itself too, at least to some degree -- I'm getting fewer forced power-downs and more successful hibernations these days -- and I've been trying to avoid Thinkpad software as much as possible in this clean, bare-metal XP installation. (Device Manager showed that the A22p has a 'Thinkpad PM Device' for which XP SP3 didn't initially have a driver, but Microsoft Update subsequently provided one from Lenovo.)


New Questions:
7) Do you know if XP's battery meter can also access these voltage and current measurements for its own internal use, even thought it apparently won't show them to you?
8) Do you know if these measurements are even available with an off-brand battery? Might they be features (or test points) built into the battery itself? (Of course I could find this out for myself by intalling the Thinkpad stuff, if I thought it was really worthwhile...)
9) One really nice feature in the Thinkpad power management on my much newer Lenovo T61 is its ability to delay recharge cycles to a specific state of charge -- great for me to reduce charging cycles on a machine that spends most of its time plugged in. I don't remeber this feature being present in the older A22p version. Do you know?

Thanks agian for your inducgence with these many "newbie" questions! -- JClarkW