[Question] E-Bike battery dead. Mopedize?

Good evening.

I am sorry if my question is disrespectful, or just plain dumb, but you guys seem pretty great at this battery-thing.

My E-Bike battery won't accept a load and it's supremely expensive to fix it, and even more so to buy a new one.

Would it be possible to hotwire the part of the battery connecting to the bike to a moped battery and go along my merry flaming way? Or am I impaired by the wiring and voltage? I have no experience with batteries and I'm generally foolhardy, but that won't stop me because I'm a veteran googler and I will end up making a moped, I'm sure, but I don't want to pay tax for that, hence I wanna keep it an e-bike.