For a race car without a charging system, I'd think a marine lithium battery would work. My fishing boat has a lot of electronics on it, with the Group 31 lead acid battery after four and half hours of fishing it would be down to 11.4v, after six hours my 90hp outboard would crank slow and the depth finders would go off when the OB was cranked. I installed a new Impulse Lithium All Purpose 105ah, now after seven hours my voltage is 13.1v and the battery still has 48% or so charge. it's pretty cool to look at my phone and see the voltage and state of charge on my battery. The new battery required a new charger too, with a 15% discount on the battery it and the charger were still over $1k. Impulse Lithium has the best warranty that I found when researching lithium batteries.