Anyone has experience on DIY batt repairs?

[edugimeno]

Hi there.
So rry if this has been asked before, I checked some pages down and couldn't find it.
I have experience in repairing different battery packs from different appliances, finding the shorted element, find the proper type for replacement, solder, etc...

Last week a friend told me that his segway is broken cause his friend borrowed it for some months and left it discharged for too long, so now it would refuse to start up

I've seen some videos about the battery inside, the control board, etc, but with not much detail.

Has anyone here ventured into "home repairing" this block? Does it have regular 18650 batteries in it? What other info do you guys know about it?

Thanks in advance!!