Battery life

[hhmcsv]

I now own 3 batteries for my Thinkpad, and with the installation of Thinkvantage Power Manager some interesting statistics of the batteries can be obtained:

6-cell SANYO:
Full charge capacity 17,8 Wh
Design capacity 47,5 Wh
Cycle count 205
Mfg. date 2005-03-26
First used 2005-03

9-cell SONY #1
Full charge capacity 69,6 Wh
Design capacity 71,3 Wh
Cycle count 605
Mfg. date 2003-11-07
First used 2005-03

9-cell SONY #2
Full charge capacity 77,8 Wh
Design capacity 77,8 Wh
Cycle count 91
Mfg. date 2006-05-15
First used 2007-03

The 6-cell battery (original with the T41) is in the worst condition, and since I got a Docking station together with it, I asume that it has been killed by sitting fully charged over long periods with charger attached.
The first 9-cell battery have been used by me in the T40 since march 2005, I think it has survived very well considering the relatively high number of cycles (which I take is calculated by total charge divided by design or full charge capacity?). And unaffected by the fact that the new battery was stored nearly two years before used. With this battery, I have been very careful only to charge when needed, and almost always I use the laptop in battery mode in my armchair or in the garden

The last 9-cell, which I got with the T41 recently, has a slightly higher design capacity, and the meter on that just now as I type is showing 5:25 hrs of time left - very good I think.

Is there any quality difference between SONY and SANYO batteries?

With such statistics on the batteries (must be stored in the battery hardware itself), I wonder whether similar numbers are stored for the Thinkpad itself somwhere ??????