9 cell battery takes nonlinear time for charging ---why?

[T400plus]

While charging I noticed it takes too much time charging after it is charged beyond 60%.I used to expect that time to charge is linear with % to be charged. Can some Thinkpad old(in usage of thinkpads) user provide his knowledge about this.

[dr_st]

It's normal. The more charged it is, the slower it charges the remaining capacity.

[T400plus]

yes,I knew that. But The charging versus time for the 9 cell is atrocious.

[Adda]

There is a relationship between how much power your laptop uses, and how fast it can charge the battery.
So under a heavy workload the battery will charge more slowly.

[Colonel O'Neill]

Agreed, the power draw from the system while it is running will diminish the amount of power that can be directed into the battery to charge it. However, it could also be the smart charging algorithm kicking in, switching to trickle charge. But with this occurring at 60%, it does not seem to be quite so probable.

[ifixthings]

Does anyone else use the option in Power Manager to only charge the battery to ~95% of its total capacity? This is supposed to help extend the life of the battery, especially if you're using it on AC most of the time (which I am).

[T400plus]

How Do I do that?
I would like to reach that option to request it to save me a lot of currency notes.Laptop batteries are very very expensive here...

[emeraldgirl08]

How Do I do that?
I would like to reach that option to request it to save me a lot of currency notes.Laptop batteries are very very expensive here...

Start your Lenovo Power Manager>>Battery (tab)>>Battery Maintenance>>and Choose Custom>>set your thresholds there. For example mine is set to start charging at 90% and to stop at 95%.

Hope that helps

[Eudoxus]

If you mainly use your ThinkPad home (or anywhere else) attached to AC adapter, then it is smarter to choose lower thresholds. For example, mine is set to stop to charge at 65% and start to charge at 15%. In this case your battery more fully uses all the power during one cycle. May 9-Cell battery is one year old. I have 10 cycles and almost the same charge capacity as it was designed (it have lost about 0.1%).