As the title suggests. A friend of mine is asking help on a custom dragster that he is building from scratch. A very cool project. Anyway, he is trying to figure out what kind of battery he needs to crank his engine. This 12v battery need to turn over his 450 cubic centimeter/7300cc engine, a few times for a few runs, and be done for the day. It also need to run the small fuel pump (negligible by comparison). No headlights, no AC or anything like that. Literally the only two circuits in his vehicle will be start and fuel. He's not even going to use an alternator, just separately charge the battery before race day, bringing a small generator to the track if he needs to.
A preliminary google search suggests that 1 amp is needed for every cubic inch of engine displacement. That would suggest that he will need a battery capable of a 450-amp draw, for a couple seconds, and maybe a few hundred more amps than that for wiggle room. From what I've seen, Headway cells are capable of 120A continuous, 240A pulse. So what I was thinking was that I could get 16 cells for him (plus spares) for a 4s4p pack. 4p would suggest 480 continuous, 960 pulse. He could easily make busbars with his metal fabrication skills.
He was saying that in his searches, he was finding 12v packs that would be $400-500 for his specs. Whereas 16 Headway cells from BatteryHookup would be $112. Could make two packs.
Somebody who knows more about car starter batteries and requirements, am I missing anything? Could this work?
A preliminary google search suggests that 1 amp is needed for every cubic inch of engine displacement. That would suggest that he will need a battery capable of a 450-amp draw, for a couple seconds, and maybe a few hundred more amps than that for wiggle room. From what I've seen, Headway cells are capable of 120A continuous, 240A pulse. So what I was thinking was that I could get 16 cells for him (plus spares) for a 4s4p pack. 4p would suggest 480 continuous, 960 pulse. He could easily make busbars with his metal fabrication skills.
He was saying that in his searches, he was finding 12v packs that would be $400-500 for his specs. Whereas 16 Headway cells from BatteryHookup would be $112. Could make two packs.
Somebody who knows more about car starter batteries and requirements, am I missing anything? Could this work?
