ThinkPad Power Manager is wrong !!!

[paultoan]

Hi,

I use ThinkPad T500 2242-33U laptop, with Windows 7 Ultimate, and ThinkPad Power Manager ver. 3.05 for Win7.

When I use battery only, about two hours, but I see remain time is more than one hour. Then my computer hibernate by battery is run out without slow battery alert.

How can I fix it? or waiting for new version of ThinkPad Power Manager?

[EOMtp]

You have a bad battery. When the remaining time "jumps" down as you describe, that mean that there are one or more bad cells in the battery.

[paultoan]

How do I know exacly my battery is good or bad?

This is information about my battery get from ThinkPad Power Manager

[EOMtp]

How do I know exacly my battery is good or bad?

Unfortunately, Power Manager is limited in what it actually "sees". The report that the battery is "good" is based on information returned from the microcontroller which is built inside the battery pack, which reports battery status it thinks is correct.

If one of the Li-Ion cells has gone bad but is not completely dead yet, then the battery pack will appear to be good, except that the bad Li-Ion cell is not capable of storing much charge, and consequently the battery moves down -- for example, from 40% to 5% -- in a step function rather than on a linear slope. In summary, regardless of what Power Manager is reporting, the condition you describe is characteristic and perfectly typical of a Li-Ion cell going bad inside a multi-cell battery pack. There is nothing one can do with that battery pack except replace the bad cell (impractical) or "live with it" the way it is (unpleasant).

[Vempele]

31°C

That's fairly hot for a battery that isn't doing anything at the moment. Are you sure the battery isn't overheating? (the message you get when resuming from hibernation is still the same). Its maximum operating temperature is 35°C.

[paultoan]

When I resuming form hibernate, the message is right, it show 5% and start charging.

I think the temperature of battery is 31°C is normal, because I am in Vietnam. And it work well when I use Vista and Power Manager for Vista. So, I think Power Manager is wrong for Windows 7.

And always (both Vista and Win7), I never recieve alert when battery is low, it only go hibernate when battery is critical. I have set alarm and sound for alarm, but when I restart computer, the sound is lost.