Thinkpads Forum

I do not know if the problem is linked to the battery or the electronics controller that works with the battery.

The problem appears in the following manner:
- I allow the battery to get fully charged while my PC is turned on. I wait until the Power Manager (PM in Windows 7) shows the battery is fully charged
- I removed the AC adapter plug from the Laptop
- I noticed the remaining battery fell gradually from 100% down to 90%, then 80% etc.
- All a sudden the PC went to sleep
- I re-connected the AC charger to the laptop immediately after
- Restart the pc from sleep mode
- Examining the battery condition it showed it had only 4% left

My PC is set going to sleep when the battery falls below 7%. My PC is set to give me a warning when the battery level falls below 20%. Because I did not receive such warning I tried to change it to 60% but still I didn't receive a warning before the PC went to sleep.

What was wrong? The battery or the charging circuit or the PM? I think most likely it is the battery but I like to be sure. I have tried at least 2 other batteries the problem is the same (the other batteries are not brand-new though) therefore I am not too sure.

I am afraid if a "good" battery that works in another laptop becomes bad when placed in my PC. Is that possible? Many thanks for reading.

From what I gather, a sudden dead battery symptom is usually caused by the "smart" chip in the battery, that something happened and triggered the shut down command to avoid any nasty thing (think explosion) from happening.

The cells may still be fine, or perhaps one of them went bad, but Li-ion cells are volatile, so it's better safe than sorry.

If it's indeed the case, unless you have the equipment and expertise to hack the smart chip, you wouldn't be able to revive the battery pack.

You may still give the battery a try on another machine.

This topic has been discussed over and over again in the past, do a search and you can find more information.

Cheers.

loyukfai wrote:From what I gather, a sudden dead battery symptom ...
You may still give the battery a try on another machine.

Thanks for taking time to answer despite the topics have been discussed.
Please summarize if you don't mind.
1) Since you suggested me to put the battery a try on another machine I assume it shouldn't harm a 'good' PC (that has a good smart chip) if I insert it a bad battery
2) How about the other way? Is it safe to place a "good" battery onto my current pc suspected of having a faulty 'smart chip'? Will doing it ruin a good battery?

From my personal experience, and as far as I've read and recall, both should be fine.

Cheers.