Thin wire will probably just catch fire or melt, if the BMS of either pack didnt shutdown the overload before that point, and if the overcurrent thru the already-overdischarged cells didnt cause them to burst into flame first.
Most likely the BMS in the battery (if it is a lithium type and not SLA) has shutdown to prevent cell damage and fire, so it wouldnt try to charge anyway. If you force it to recharge, without checking the cells first to see why its not charging, you could potentially have a pack with fire risk now or in the future. Thats why the BMS are made to prevent charging if it drops below a certain level in the first place. (otherwise itd just let you charge it up even with a totally dead pack, if it didnt matter).
If it is an SLA or BMSless lithium pack, youd want to use a DC-DC converter to limit the charge current to a very tiny amount, a few hundred mA at most, until its back up to the point it will charge normally. But again, if its a lithium type pack, it could be a fire risk from this point on. And if its an SLA pack, the cells are probably sulfated and wont fully take the load the scooter will place on them even if they will reach and hold full voltage again, and/or they wont last much longer after this and will all need replacement.