Interesting battery...

[mmmkay]

The R40 I got was refurbed,and it came with a dead battery which the refurb company is sending me a new replacement for..

It only held 15 min or so of charge. So when it came time to go home after classes, I just shut the laptop closed to suspend it and unplug and go home. Anyway, the laptop crashed during the suspend and it ran out of battery some 15 minutes later. I didn't catch it till I got home to plug it in.

Now normally it says about 1h30min to full charge,but I noticed instead it said about ~5h to full charge. Strange. Prior to this the reported full charge capacity was about 15ish Wh, from a designed capacity of 57.6 Wh. Now it reports 29.34 Wh out of 57.6 Wh

Crazy So after it fully charged up I unplugged it.. and I've been MSNing and typing away for the last hour and a half or so!

So battery capacity is up from 26.9% of designed capacity to 50.9% of designed capacity!

Oh and BTW: The ThinkLight is freaken awesome (it's 1:58AM now...)

[mmmkay]

I've been stuck at 3min remaining for some time now.

On full brightness.. for way more than 3 min.

I think I'm on my second hour.. about 20 min in.

hehe.. Cool!

[tfflivemb2]

The reason that you have an increase is because you reset the battery by reconditioning it. (ie. letting it run down to zero)

[mmmkay]

Yeah, though I think IBM's use of "recondition" is a little weird.

Li-ion batteries don't like to be deeply discharged. I'm pretty sure it's just the "smart" monitoring of the battery that needs to be reset.

I tried to do that yesterday by running it down last night, but it didn't record any higher reported Wh values, although I did have it sitting at 0.00 Wh for quite some time.

I'll see if the PC Doctor bootable CD that IBM provides can do something to help me recalibrate the battery.

[tfflivemb2]

True, it is not recommened to deeply discharge Li-Ion batteries ofter. However, it does need to be done with these from time to time...maybe once every other month or so.

According to IBM's Battery Maximizer, it might have to be done 1-3 times, before it will increase...if there is a potential for increase.

Reconditioning your battery can increase the full charge capacity of your battery. It is recommended that you let the battery run to less than 3% at least once a month.

Occasionally, it may be necessary to "deep cycle" your battery one to three times to give it optimum performance. This will require you to let your battery run completely down, and then to recharge it fully. It is recommended that you charge your ThinkPad overnight for a full charge from a deep recharge condition without leaving your ThinkPad powered on. A brand new battery should be fully charged overnight before its first use.

[underclocker]

Be happy! I've had this result once or twice (rarely). Usually, it goes up or down a little. Very nice.

[tfflivemb2]

Yeah, I only use it in rare cases, where the battery seems to be holding less than it should OR there is next to nothing less on the battery (ie. nothing to lose).

[mmmkay]

Yup. It's bad but they need to be recalibrated.

Ended up getting nearly 3 hours out of it with full brightness and power management disabled. Not bad. I could live with that for a while at least till my new battery comes.

[underclocker]

The other particularly good thing about the R40's is that they have 8 cell batteries. With Pentium M CPU's, the new batteries could go 4+ hours.

[Terrahawk]

I had one that went from 50 Wh to 9 Wh after recalibrating. Obviously, the previous owner did not do any recalibrating of the battery electronics.

Since then, I've bought a new battery and have 5+ hours of usage for now