My son wanted to take my 08, 700 out this winter when I was gone to pull a sled, it was -5 F so he killed the battery trying to start it. He then used my big charger which ruined the battery so I bought a new one. It still wouldn't start so I looked it over and found the EFI fuse burnt and I replaced it. Still no luck. Well I got it to finally start, it was a weak, not fouled plug. So I took it for a spin and it popped the EFI fuse (10AMP). I put another one in and turned the key on and the fuel pump turned on and popped the fuse again. So at this point I had to get it back home so I put a 15 amp in it, yes I know that’s not good to do but had to get it back home or push it, it did not pop that fuse so when I made it back home I put another 10 Amp in and same thing, POP. Can anybody tell me what this could be caused from? Could there have been more damage from charging the battery wrong the first time?