my uncle has bought a 54 ford truck this is a cherry little ford but he says if you don't do every little trick just right to get it to start the 6v will leave you setting,he wants to keep the truck all original as possible he been told he could put a 12v battery on this 6v system and it would give him the extra charge he needs. true/or false? what are his options to be able to stay with 6v,and not worry about the starting power? wjr