Today I finished soldering up my first Nimh Battery packs (9 x 4 cell GP 3700 unmatched vis and 3 x matched packs).
I'm charging each one a 5 amps and timing the discharge @ 20 amps (only discharger I have at the moment).
Anyway two of the batteries (so far as I've got 7 to go) have behaved differently.
The first one was different because it charged to .05 (cut off at 6.04) volts less than the others and has been the only one to get hot (not slightly warm) to the touch during charge.
During discharge this battery lasted 2 min less than the others (they lasted approx 20 min).
The second one is very odd.
It charged to 6.08/6.09 like the rest (and only slightly warm) but again the discharge time (down to 3.6 volts) was 2 min less than the rest. But the really odd part was that as it got down to 3.8 it started to hiss as if it was leaking.
Not the normal venting sound I've heard on other batteries (and no funny smell or anything) , this sounds like a slow leak and if the battery builds up it's voltage after a rest it's fine until once again it gets down to 3.8 when put on a discharge.
Any ideas what this might be/can it be fixed or should I just junk them?
Thanks in advance.