Thinkpads Forum

Hallo,

I have question about Battery gauge reset feature.

Recently my notebook's full charge capacity drops to 80% (57Wh design capacity about 45Wh real capacity). The Power manager announce me that it is right time to perform battery gauge reset. I said ok, I will do it over night. Before I started reset I closed all applications and give it a try. In the morning I found, that the reset doesn't help at all and even drops to 38Wh (68%). To be honest I haven't been just disapointed I was angry. I used Lenovo feature to lower quality of my HW? Ok, maybe I went wrong.. I said to me. I will try it again. I restarted computer, have the background services as clean as possible and try it again. Now I have only 65% of designed capacity and wondering if there is (hopefuly) some way to get more energy to my battery. Is it possible?

My configuration.
Lenovo ThinkPad T400 - 6 battery cell (1 year old)
Windows 7 (64b)
PowerManager 3.05

Thanks for any advice or explanation.

nanux wrote:Lenovo ThinkPad T400 - 6 battery cell (1 year old)

How many cycles is the battery showing?

Cheers,

Bill B.

Cycle count: 110

There's is no way that Power Manager did something to your battery. A reset simply makes the guage reflect what capacity is actually left in your battery.

And to add to what Harry said - it is not always 100% accurate. Sometimes 2 or 3 resets are required to better reflect actual remaining capacity. Before the reset it showed 45Wh, now it shows 38Wh - the truth is likely somewhere there in the middle.

It is not very common, but also not unheard of - to have a battery degrade to ~70% of the capacity within ~1 year and ~100 cycles. It's somewhat luck of the draw.

OK, now I understand it better. But what if battery reset set the capacity to less than it is. Then the battery can't be charged to its real capacity?

Have you any recommendation what should I do? Could another reset help?

BTW: it seems to me, that 65% for one year is a lot. I've set optimalization for battery lifespan and tried care about the battery...