Do NOT connect it to your car battery.
I’ll help you out in that part, what you have inside the charger is a 7s6p (7x series, 6x parallel) 18650 brick, 42 cells in total. Each one 4.2V 2200 mah, for a total of 25.2V, 13.2AH/332Wh.
Just get another one with similar specs (not less than 13AH/330Wh – more would be okay, and voltage needs to be 25.2 as well as 7x6p since we don’t know what the balance board/battery management in the battery is looking for).
I’ll have a look in a second myself, gotta pick up the wife first.
I think both Struth and Wigwam are irresponsible beyond belief, Struth suggesting a charger that’s not able to charge your battery in the first place, and Wigwam suggesting that the batteries are “recoverable” – they’re not. They’re irreparably damaged. You could get them to take charge again, but the damage doesn’t go away, that’s done and dusted – LiIon batteries take physical as well as chemical damage internally when deep-discharged, and that can’t be repaired since you can’t open those batteries. They’ll catch fire (violently so) at contact with oxygen.
Those are the batteries inside your pack, 42 of them. First rule in regards to anything to do with 18650s or 21700s: don’t screw with them.
Prior: SEAT Ateca Xcellence Lux 1.5 TSI DSG MY19, VW Golf GTE PHEV DSG MY23
Current: Hyundai Ioniq 6 Ultimate
Next: we'll see what's available in 2028.