Lithium cells are 4.0 volts, so in a 12volt battery there is a series/parallel combination to get your voltage and current requirements. There is a regulator inside the battery pack which charges and monitors the individual cell packs. These are designed for a fixed input range (usually 10-15 or so volts), and have "thermal runaway" protection as well, should the pack get too hot and go kaboom. Using a generator should not be a problem, it would only have affect if the voltage from the generator is below the input voltage to the battery pack (like when idling at a low RPM). If these car -type lithium batteries are sold to directly replace the 12volt lead acid jobs, all the regulation is done inside the battery.
I agree with the recommendations for Odyssey AGM batteries. I modified the original battery box in my '32 Roadster to fit the PC925MJ. The MJ indicates a metal jacket. The jacket helps to isolate the battery from the exhaust heat. It has been my experience that using the correct charger/conditioner does extend the life.
https://www.jalopyjournal.com/forum/threads/car-battery-in-an-ammo-can-no.1329097/#post-15463939 There is another thread here for this same question, and the Odyssey batteries were the most common reply. https://www.jalopyjournal.com/forum/threads/small-battery-reccomendations.1175066/page-2 There's another from a decade ago. Same thing.
Thank you for all the replies; it has been a tremendous help! And yes, I am guilty on my post of not specifying displacement. I wasn’t clear enough that I was more interested in what was available for the small physical dimensions as opposed to the CCA rating. Any basic engine in the 300-400 cid range can do with a similar battery. If I did have a 600 inch engine with 13.5-1 compression, a tiny battery would not even be a consideration. I would like to go with a conventional battery but the car is chopped channelled and sectioned, so there just isn’t room for a conventional battery without eliminating a seat or something. So, thanks again for the help and I will try and and do better!
I have a Braille 2015. This is my second Braille. It’s got a little more umph than an odyssey pc680 but fits in a pc680 mounting box with small modifications.
The idea,that there is no room for a Bat,is pretty much same as" there no room for a V8" I guess if your young,that type of thinking can be done,but really a good battery is as much part of the rod as the V8,as in after the starter motor was invented. Point being,battery dose not look bad,to any one! So if it shows> that's AOK. In most of my hotrods,I've put it under the floor or seat. Hung behind rear axle is good for more bite as well. Main thing,is not to have to push start it> That gets way harder as you age...
I used a XS Power S925 in my roadster. with 625cca it cranks over my heathly small block with no problem. and it will crank for a long time. .
I hear you and agree fully. However the car is a 1932 Ford with stock gas tank. So it can’t go behind the axle. It’s a 2-door sedan, so if it goes under the back seat it hits the rear bones. If above, there is no room for rear seat. Car is sectioned so that makes it even tougher. Car is channelled, so putting a conventional battery under the floor makes it so low it sticks down below the frame rails. Because the car is channelled, front seats are flat on the floor so there is no under the seat. Ahead of the firewall, there is a 1956 Chrysler Hemi, so no room there. I made a mock up of the smallest conventional battery I can get and went around the car and there is virtually no place to put it besides under the dash, or sitting on the floor. Both places take away from the interior space already at a premium. But we will get there!!!
This doesn't address physical size but have always used the "rule of thumb" that you need 1 CCA per cubic inch of displacement. That has served me well but I don't have any 13:1 fire breathing engines. Lynn
Use a hand crank converter to preload a internal spring. When the release is tripped the spring drives a starter mechanism and it spins the engine to start it. Made of steel with steel teeth and some internal plastics. DO NOT over crank or spring failure may happen. Decently constructed but it is a novelty for our world and even though it's neat.
The Jalopy Journal
