Weird Battery capacity...help?

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Mugrunty · #1 Post by **Mugrunty** » Fri Dec 08, 2006 12:30 pm

Hello,
I got a funny question that doesn't make much sense to me. Just two days ago my battery capacity for my 6 cell was 52.62Wh. Then for some reason yesterday it suddenly dropped to 48.45Wh. The design capacity is 56.16Wh. Now this seems like a rather sudden drop so i tried a battery gauge reset but nothing changed. The other funny thing is that I only have 29 cycles on this battery and I've had it since mid-August.
Has anyone else had some kind of weird drop like this?
Is it supposed to be this low after only 29 cycles?
Just thought it was a little weird cause a couple of my friends have the same laptop (T60) with the same battery, and have like 52Wh and over 100 cycles.
Any help would be great, thanks!

-Robby

Mugrunty · #2 Post by **Mugrunty** » Sun Dec 10, 2006 8:40 pm

Anyone?

christopher_wolf · #3 Post by **christopher_wolf** » Sun Dec 10, 2006 8:45 pm

Did you do several "deep cycles" of your Thinkpad's battery? In a sequence, several deep cycles can lessen the overall capacity of the Li-Ion battery.

kay.one · #4 Post by **kay.one** » Sun Dec 10, 2006 9:31 pm

just a question, what application did you use to get number of cycles on your battery?

#5 Post by **Kyocera** » Sun Dec 10, 2006 9:42 pm

Battery information in Power manager will show the cycles.

xcgames · #6 Post by **xcgames** » Sun Dec 10, 2006 10:04 pm

christopher_wolf wrote:Did you do several "deep cycles" of your Thinkpad's battery? In a sequence, several deep cycles can lessen the overall capacity of the Li-Ion battery.

how do you define deep cycles

#7 Post by **Kyocera** » Sun Dec 10, 2006 10:20 pm

Deep cycles means to drain the battery way down probably below 5%. Lithium ion batteries have no memory effect, can be damaged by overcharging or overdischarging, and have a sloped discharge curve.

laundromatt · #8 Post by **laundromatt** » Sun Dec 10, 2006 11:31 pm

wow, and i thought my battery declined fast.

i started at 56 Wh, and i'm at 49 Wh now after 145 cycles.

eTools · #9 Post by **eTools** » Mon Dec 11, 2006 2:02 pm

On my T43, at only 22 cycles I'm down to 48Wh from 51.

Seems normal to me. :-S

Mugrunty · #10 Post by **Mugrunty** » Mon Dec 11, 2006 9:32 pm

Nope, i Didn't do too many deep discharges. I had maybe a couple where i discharged it down to 5%, but normally I only went down to like 65%. I'm at a college where everyone gets the same laptop and stuff so i compared my capacity with a few of my friends. They have cycle counts of 60+ and have capacities of 53Wh. I thought it was weird how I had 30 cycles and a capacity of 48.45Wh. Ill have to watch it to see if it continues to drop. Thanks for all the replies!

P.S.- Yeah i used the ThinkVantage power manager for all these values. It still says I have a good battery, so thats cool.

pianowizard · #11 Post by **pianowizard** » Mon Dec 11, 2006 10:25 pm

If your battery continues to deteriorate so rapidly, you should complain to Lenovo and might get a free replacement. I remember someone on this forum did that several months ago.

Badger · #12 Post by **Badger** » Mon Dec 11, 2006 11:26 pm

My ultrabay battery did that. It was only a month old so I told Lenovo and they sent me a replacement, no hassle. Then the replacement did the same thing after only two weeks.

Now the whole T60 has been at EZserve since Nov 29, they wanted to "diagnose" that problem, and I had some monitor issues and a warped piece of plastic for them to replace. I included a letter with the laptop detailing my problems, and mentioned that maybe if PowerManager was configured so that it didn't allow the batteries to drain all the way to 0% that maybe they wouldn't have so many problems with batteries losing their charge after a relatively minimal amount of cycles.

christopher_wolf · #13 Post by **christopher_wolf** » Mon Dec 11, 2006 11:39 pm

Badger wrote:[...] maybe if PowerManager was configured so that it didn't allow the batteries to drain all the way to 0% that maybe they wouldn't have so many problems with batteries losing their charge after a relatively minimal amount of cycles.

It is, to some extent. You can't really do that on the main batteries, only warn the user and try to suspend/hibernate/shut down the system to prevent further drain. Although I don't really know how well the thresholds will hold for the Ultrabay battery; from what I have seen, it almost drains the entire thing each and every time it is used before going on to drain the main battery.

planetf1 · #14 Post by **planetf1** » Tue Dec 12, 2006 10:31 am

I've had 2 UB batteries behave like this. The one from Aug is now down to 32% capacity...

Mugrunty · #15 Post by **Mugrunty** » Tue Dec 12, 2006 4:05 pm

Yeah, I read about the UB batteries dying after only a short time on these forums. I thought the main batteries were good though. I just monitor it over the next few months over break!

But if it drops too much more then ill take a trip to the help desk and ask them whats going on. (Help Desk is IBM certified place at my college.)

Weird Battery capacity...help?

Weird Battery capacity...help?

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