Well, to be fair, I THINK it may be charging on some sort of trickle charge, but the charging lights dont light up and its been getting 18.9 volts for about 4 days, and the pack is still not charged to correct voltage, though it has crept up.
I called Imalent and they are sending me a new one under warranty. But i was wondering if someone has tried to repair or reverse-engineer thE pack in any way?
Recommend you stop the attempt to charge immediately. At this point, won’t help, could hurt. So, you have to check.
Don’t have one of those, but I have opinions anyway: 
Has to be a protection circuit in there. I’ll bet it’s failed. Cells may be OK, some anyway. I’ve seen a number of protection circuits fail.
I see 2 screws on top. So…go for it and see. With appropriate caution you have nothing to lose. May harvest some decent cells out of it.
If you do, they are suspect until thoroughly tested.
Note-$130 for a 4-cell battery? Really? Damn!