HP41c rebuilt battery pack with leakage

[aurelio]

I rebuilt a couple of battery packs for the 41 few years ago, with NIMH cells, barely used.
I prefer to use infact alkaline N cells to have no problems with the card reader which requires a large amount of power
I was surprised, checking their integrity in these "stay at home" days, noticing the presence of leakage on the contacts...never I found this situation even with the original batteries before the rebuilding, they were dead but... very clean
I know that a rise in battery temperature can generate gas which cannot be absorbed within the battery case, and there's aa safety valve in order to prevent them from exploding but... I don't remember any rise of temperature during the charge of the packs or their usage
I was going to give them a charge, but I was worried and finally I opened the packs and found actually leakage in both them. I really thought to throw them away, the pics I posted yesterday showed the situation, not cosmetically pretty to see.
I removed and cleaned the elements and found that instead they are still alive and working.
I've rassembled everything and charged., now the voltage is about 6V and everything seems to work properly, of course waiting for a replace at the first chance.
Cheers