Thinkpads Forum

Ok my problem is the following. I am not sure if this only happens after I installed Windows 7but when my battery is at 30% my T61 suddenly hibernates and after rebooting reports 0%. I am not sure what to do.. Is it because I installed Windows7 ? i was running xp before. I am using the ThinkVantage Power Manager 3.05.

Hi and welcome to the forum.

It is possible that your battery meter is not calibrated and so the computer does not read it correctly.

Try calibrating the battery (performing a battery reset) using the Power Manager.

dr_st wrote:Hi and welcome to the forum.

It is possible that your battery meter is not calibrated and so the computer does not read it correctly.

Try calibrating the battery (performing a battery reset) using the Power Manager.

first of all thanks and thanks for the fast reply. I will try a battery reset (I guess it has to be fully charged.)

Could it be that a battery reset is necessary after installing Windows from scratch ?? (I installed Windows 7 from a DVD, not the pre-configured XP i usually install from the recovery partition.)

For a battery reset the battery has to be at 100% btw ??

When you start a battery calibration cycle, it is fully charged, then fully discharged, then fully charged again.

This needs to happen because the meters do not actually know for sure how much power is left in the battery, they can only measure the current that flows into/out of the battery. And because the battery loses capacity over time (without current flowing through the meters), those measures stop being accurate and need resetting.
The battery gets fully discharged and then the meters can measure the current needed to fully charge the battery, providing an accurate measure.

This is most likely the reason for the jump from 30 to 0%, the meter might think the battery has...say 30Wh of power when fully charged, when it really only has 20Wh. So when it thinks there's still 30% left, the battery is actually empty.

This has nothing to do with your operating system, be it windows or linux or whatever, because that information is stored on the battery itself.

I have a similar problem with my 4-cell battery, it only has 50% of the original capacity, and recently it started jumping from 20% to 0%.
The thing is, calibrating it doesn't work, because the same thing happens when charging, it jumps from say 60% (not sure when it happens) to 100% and reads fully charged.

Weird

bonevbs wrote:... when my battery is at 30% my T61 suddenly hibernates and after rebooting reports 0%.

Li-Ion batteries fail precisely with the symptoms you describe. Resetting the battery gauge will not have any effect on the underlying problem, i.e., a battery with one or more bad cells which have failed.

EOMtp wrote:Li-Ion batteries fail precisely with the symptoms you describe. Resetting the battery gauge will not have any effect on the underlying problem, i.e., a battery with one or more bad cells which have failed.

so even if I recalibrate it and everything is ok, then the battery is ok and if I recalibrate and it's still happening the chance of my battery failing is high ?.

What's weird is that this battery has only 30-40 charge/recharge cycles behind it....

anyway let's see if it still works after the recalibration.

Recalibrating the battery should stop the meter from jumping from 30% to 0%, but it won't restore the lost capacity.

and what i want to know too is: if this doesnt solve the problem, is it covered under the 2-year warranty or will I have to buy a replacement ?

wap32 wrote:Recalibrating the battery should stop the meter from jumping from 30% to 0%, but it won't restore the lost capacity.

oh, ok, because you said ur problem couldnt be saved by recalibrating... anyway i will report back after recalibrating....

im still interested if i get a replacement under warranty in case my battery has a defective cell... (and can it be proved that one cell is defective)

greetings, and thanks for those fast replies, very good community here, shame I didnt know this forum earlier.. had enough problems with my T61 so far (sadly, i like it very much )

Well, in the past I've had the same problem and recalibrating it stopped the meters from jumping, but now it doesn't seem to work.

I know there was a recall recently for T61 4-cell batteries, you should check if your battery is one of the faulty ones.

Unless they are part of a recall, battery warranties are only one year.

wap32 wrote:Well, in the past I've had the same problem and recalibrating it stopped the meters from jumping, but now it doesn't seem to work.

I know there was a recall recently for T61 4-cell batteries, you should check if your battery is one of the faulty ones.

hmm couldnt find anything on a t61 battery recall.. at least not on the lenovo homepage ? do you have the link for it ??

I think this was the one.

As the symptoms, they mention "Low battery capacity, as indicated by short battery run time or sudden drops in the battery fuel gauge".

wap32 wrote:I think this was the one.

As the symptoms, they mention "Low battery capacity, as indicated by short battery run time or sudden drops in the battery fuel gauge".

thank you very much. After recalibrating the battery it still jumps from 20% to 0%. I think I will check if my batteries FRU is in that list and then try to replace it. do I have to run any diagnostics etc to get a replacement one ? (I have very bad experience with lenovo tech support >.<)

According to the site you have to run the "Battery Diagnostics Tool" that will determine "if your battery has failed due to this issue and qualifies for a free replacement".

I have had exactly the same problem after installing Win 7 64. My battery only lasted about 30 minutes in total and when I recalibrated, the meter showed the battery health as poor. I ran the Battery Diagnostics Tool and it came up as requiring replacement and automatically put in an order on Sunday evening. The new battery is winging its way from Texas to Manchester UK via UPS as I write.

I don't think that Windows 7 is the direct cause. The reinstalled Power Manager needed recalibration anyway, but it was a while since the Thinkpad last operated on battery. I checked the battery when the "recall" was first issued (Lenovo say it is an extension of the guarantee for affected units, not a recall) and it passed the test then, so it is obviously worth re-testing your battery if you are having problems with poor battery health.

J