[ltp] "Hard reset" Thinkpad battery cycle count; exercise them?

[David A. Desrosiers]

 	I called IBM about my two T42p 9-cell batteries not holding 
more than 2-2.25 hours worth of charge, and found out that the 
warrantee on those batteries expired THAT DAY, and they wouldn't honor 
a replacement on them.

 	I "firmly" explained that these batteries have NEVER held more 
than 2-2.25 hours worth of charge, even when new, which is why I 
bought two of them when I originally purcahsed the laptop. The IBM 
salesman who completed the sale of this laptop even told me that the 
9-cell was the *ONLY* battery that would work, since the "regular" 
(6-cell?) wouldn't even give it 30 minutes of life.

 	In any case, the laptop + 2 batteries is going in for repair 
and diagnostics/replacement, because the tech I spoke with believes 
there has always been something wrong with my system board that is 
causing the batteries to drain faster than normal.

 	He suggested I put the default OEM XP image on a spare drive 
and install the latest EC and BIOS updates, as well as the other 
updates to drivers and PM tools, which I've done.

 	Power Management is set to MAX levels on Linux and on the 
default XP OEM build drive I put in here recently, and according to 
Windows, I have 2:11 (2 hours, 11 minutes) life in the battery when 
charged to 100%.

 	As I was poking through the Windows Battery Maximiser tools, I 
noticed something called "Battery Recondition". This isn't present on 
the Maximiser on my T23, so I tried it.

 	It claims my battery has been charged 240 separate times since 
4/2005, which I find a bit odd, since I mostly use this on AC, and the 
battery in question is my "spare" battery that I use for travel 
purposes. This would mean that I'm charging the battery every 1.5 
days, consistently for the last year, which is downright false in this 
case. The only thing I can think of is that it considers going to 99% 
and back to 100% as a charge cycle, as I unplug to move from one 
location in the office to another, or go from the AC adapter to the 
dock.

 	Can I reset this cycle count, and start anew? I found this 
interesting link[1] that describes "exercising" the batteries by 
draining and recharging them over and over, which seems to breathe 
life back into them (on the Apple batteries at least).

 	Can this really be used to help in this case? Is there an 
external battery charger that I can use to do the same thing, for the 
T23 and T42 batteries? (discharge to 0%, then recharge slowly to 100%, 
and back again).

 	I'm running out of options, and I'd really rather not throw 
away two (expensive) batteries if I can still revive them from the 
dead.

 	The other thing I'm wondering, is why Linux doesn't yet have 
this capability. The Windows tools seem to be able to disable the AC 
charging circuit, even while plugged into AC, which allows the battery 
to drain, then recharge when it reaches 0%, and back again. Would this 
be difficult to add to the Linux side of things, by poking the right 
values into the right registers? Just a thought... it would be easier 
to do unattended, vs. having to drain on battery alone, then plug in 
AC and charge to full, over and over again.

 	Thanks all, for any useful tips and/or suggestions.


[1] http://www.macintouch.com/laptopbatt.html


David A. Desrosiers
desrod@gnu-designs.com
http://gnu-designs.com