T41 2373-TG5 Battery problem

[jimmy274]

Well, I'm not sure it's a problem, really... but... I have an issue regarding battery on an T41 Thinkpad. Up until yesterday, the battery ran ok, but this morning I tried to power up on battery and nothing...
Then I tried on AC - runs fine - it even charged the battery pack to full 100%, but the laptop would still refuse to power up on battery alone - completely dead.
I measured something like 12.45V on the main battery contacts, and 8.45V on the middle ones (using the '-' terminal as Ground), if anyone would like to share his/hers voltmeter readings with me - I'd be very grateful.
The battery itself is pretty old - 10-2003 is the first used date, so I guess it\s worn out. The strange thing, though, is that the battery has only 21 cycles (close to impossible). It's capacity is currently at 25Wh.
Since my friend gave me the laptop for a test drive (I still didn't buy it), I would like to know if this is merely worn out battery, or a more complex power circuitry problem (if there could be one). I would hate to give my T23 dragon away if this one can't even work on battery.
Oh, and btw, I updated both the bios and the embedded controller program to the latest.
Anyone got any clue? Please?