120 Amp Battery Charger

I have a freind I’m helping design a hybrid system for a little sprite.

He wants more range and as noted in another thread you can use a genset to power yourself along for those days you travel more than 30 miles.

We have set up a list of components but we have come up with one problem and maybe you can all help. I’m very new at this. I suggested this to him.

He is using a 22HP V-Twin Punsun Diesel he already has. I suggested he mount it to a cheap 15KW Genset he found on Flea-bay. It puts out 125 amps at 120 volts. He wants a little screamer and to keep things easy I suggested he find a way to cram 10 12 volt batteries in there and run a 9" or larger 120V motor. Again he wants the best of both worlds both a kick ass screamer and long distance car. So here is the problem.

How are we going to find a charger that will put out 125 amps. A 50 amp charger runs about 3 grand and he is not about to fork out over 6K for a charger. I mean heck a ambulance alternator can put out 200 amps at 12V with some very simplistic technology. Why can’t we put out 125 amps at 120V???

By the way I’m assuming 125 amps would be more than enough to sustain a car in most instances?

Thank you sure could use the help. We are tired of waiting for GM to save the world and come out with ■■■■. Figured we would do it ourselves.