Cheap USB car adapter fried my phone, now it won't charge?

I was charging my phone through a cigarette lighter USB adapter i got from the dollar store, and i noticed the adapter stopped working (LED was off). I fiddled with it to make sure it wasn't just loose but the light didn't come back on. I also noticed that my phone had stopped charging so it was officially dead. I checked the adapters fuse and it was still intact, but being from the dollar store, i wasn't really surprised it broke.

The next day, I noticed that my phone wasn't charging when I plugged it into the cable. I tried my iPad with the same cable and it started charging right away so i knew the cable wasn't the issue. I tried charging from the PC, but i just get a USB device not recognized error when I plugged it in.

Long story short, after extensive troubleshooting on my part, as well as a trip to two repair shops (the battery and charging port were both swapped out to no avail) I was told it was most likely a problem with the logic board.

I opened up the phone and began testing. The battery is indeed good. It reads 11.6~11.7 Ma on my multimeter which sounds right, but the battery connector on the mainboard is only reading 0.3 Ma. Definitely a logic board problem somewhere.

On a side note, I did discover that the phone will charge, albeit VERY slowly, if i plug it in, wait for it to get enough juice to boot and then turn it off with the charger still attached. This does cause the phone to become very warm as it charges though.

Sorry for the long post, but I wanted to be thorough.

Any ideas?

Also, since my battery is still good, would one of those wireless charging cases be a sort of workaround if i can't fix this, or do they all use the data port in some way?

Thanks in advance.