What do you mean by "12V batteries"? Are you thinking of using lead-acid batteries?4. Also, anyone know of a good resource to find 12V batteries for EVs?
Very few people would use lead-acid for a car now; they're just used for low-speed vehicles, because they don't store much energy for their weight compared to lithium batteries. People are even ripping out lead-acid batteries from previously converted cars and rebuilding them with newer technology.