How long does a battery reconditioning last on a T42?

[giasoldacastlar]

Hi,

sorry to bother all you, but I checked the forum and didn't find an answer. I started yesterday (for the first time) the battery reconditioning process on a T42 (23734WG) with a standard 6 cells battery. When I started the reconditioning process the battery was fully charged.
Now after more than 10 hours the battery is back to 100% but the button still says "Stop battery reconditiong".
Is it typical? How long does it usually last? Would it harm the battery if I stop the reconditioning process?

Thank you very much for any advice

Regards,

[giasoldacastlar]

After more than 12 hours I was needing the laptop so I decided to press the "Stop battery reconditioning button". I realized that possibily the reconditioning process was ended long before as the software asked me if I liked to recondition the battery.

Now if I enter the battery information menu it says that I reconditioned the battery the last time today, as it should be.

Just in case you might be interested, the battery was manufactured by SANYO on 2004-09. Now after about two years of usage it shows a cycle count of 199 and a remaining capacity of 22.68 Wh (against the original 47.52 Wh). It's a 48% wear out in two years of intense use and it's not too bad for me (the battery should last two hours now).

[giasoldacastlar]

More news. I let the battery charging all the weekend as I didn't have to use the laptop. After that the remaining capacity went up to 25.10 Wh and it discharged down to 1% in 2:07 hours

So I suspect the reconditioning of the battery was not completely finished. The next time I'll set up the reconditioning with more than 24 hours ahead.

[Paul Unger]

Hey--no bother! You've described something I've been thinking about for a while. That's what this place is for.

Sounds like you were successful; many others complained that reconditioning the battery 'killed' it . That's why I haven't done it yet . . . Mine is at 20.99Wh @ 197 cycles. Says it's good for 1:48 with the power settings I have. Not stellar, but I'm not sure I want to risk my battery for a gain of a couple of minutes.

Just curious: any idea how long your battery was lasting before you reconditioned it? I see it went from 22.68 to 25.10Wh, but what did that translate into in minutes?

Paul

[christopher_wolf]

The batteries that I have seen that actually got a benefit from the built-in software gauge reset would also, typically, do the same thing with a deep cycle and the gain would be fairly substantial (almost 30 minutes); the ones that didn't respond that way either didn't gain or actually, according to the battery gauge, lost capacity after either a deep cycle (down to about 3%-5% remaining charge before a shutdown) or a battery reset.

The reconditioning process should stop whenever the gauge hits the charge threshold around 97% or 100% if it makes it there and it should silently stop and go back to normal. The biggest thing that it does is a recalibration, so if you did terminate it early, thereby leaving some errors in recalibration, that should work itself out after a few deep cycles of the battery. Try doing that manually in case the reconditioning process hangs again.

[tomh009]

Sounds like you were successful; many others complained that reconditioning the battery 'killed' it . That's why I haven't done it yet . . . Mine is at 20.99Wh @ 197 cycles. Says it's good for 1:48 with the power settings I have. Not stellar, but I'm not sure I want to risk my battery for a gain of a couple of minutes.

Just curious: any idea how long your battery was lasting before you reconditioned it? I see it went from 22.68 to 25.10Wh, but what did that translate into in minutes?

That's a gain of about 10% in battery life. Even more interesting would be to know what 25.10 Wh or your 20.99 Wh is as of a percentage of the battery design voltage (which the utilities show, too).

My X31 battery is at 36.92 Wh with a design capacity of 47.52 Wh for 77.7% of original. And that's after 670 cycles ... I only do occasional conditioning, and then only manually (full charge, run down to zero, rinse and repeat).

[giasoldacastlar]

Thanks everybody for answering to the post.

I must say I didn't notice a much longer lasting of the battery after the recalibration, may be only 10-20 minutes. What changed is that now the time left (or percentage of the charge) showed in the taskbar is reasonably accurate and that the charge doens't drop dramaticaly (let say from 23% to 3%) at once. The battery works fine thus.

What is even more nice is that a second deep discarge (I was forced to do yesterday working on a train) pushed up the full charge capacity to 26.93 Wh! I might be absolutely wrong, but recalibration seems did something more that what a few deep cycles would have (I deep discharged the battery on a regular basis all along the two years of usage)...

tomh009, the original capacity of the battery was 47.52 Wh

Finally, I used PassMark's BatteryMon to check the time left on the battery; after the recalibration the "battery information" window displays a "full charge capacity" of 22.68 Wh which differs from what I get at the same time from IBM's "battery information" (26.93 Wh). Might it be that the recalibration process wrote somewhere in the ACPI system the new capacity it detected when it ended (22.68 Wh was the value IBM's "battery information" gave me after the recalibration)?

[tomh009]

I must say I didn't notice a much longer lasting of the battery after the recalibration, may be only 10-20 minutes. What changed is that now the time left (or percentage of the charge) showed in the taskbar is reasonably accurate and that the charge doens't drop dramaticaly (let say from 23% to 3%) at once. The battery works fine thus.

Good to hear that the battery is working better. I definitely agree that an occasional deep discharge improves the accuracy and avoids that sudden drop when you get down to the 10-20% range.

[giasoldacastlar]

More on the battery. I went through several deep discharge over the last days and the full capacity of the battery kept changing. It went down to 24.51 Wh, then to 24.08 Wh and finally up again to 25.44 Wh. It is likely that this is always the case, simply I didn't pay attention in the past.