So I picked up a Smc 6500 70c 4s battery. Still debating on a charger. Still thinking I want a dual charger cause my son will be running a different type of battery and would like to be able to charge both at the same time quickly.

A question about powering off a car battery or marine battery. Are they just as good at powering dc chargers as say the converted servers? When charging from vehicle is it running or shut off, if off what's the effect on the battery? I do have some deep cycle marine batteries for my boat if these are a good option.