BOD on my T21. Little fix??????

[rrete]

Hi to all!
This is my first post here. I'm a IBM collector (desktops, intellistations and some servers) now I'm starting to collect IBM laptops, and actually I've got a T20, T21 and a 600E. Three are second hand piked up from ebay.
The T21 when came to me had the BOD, so I disarmed it to investigate the IC that causes this problem, when I put all pieces together again I forgot the bios battery, then the T21 power on normally, without time and date of course, put again the battery bios... BOD!!, put away bios battery and press power for a little and boots normally.
Now I've T20 without bios battery and works perfectly always boot (firstime I push power) y can put the charger all night, works with main battery or AC conected no problems, only input date&time every boot of course, but for me it's a very little problem