Automotive batteries don't come with the same types of capacity ratings printed on them as LiPo batteries. They only come with a stated cranking amperage capacity, such as 540 amps, 650 amps, 750 amps, etc. If you look at the battery in a passenger car, the label will read something like this: BXT 65-650. BXT 65 is the battery series, or the dimentions, if you will. A 65 series battery fits a certain vehicle. A 34 series battery fits a different veh, etc. The second number, 650, determines the amperage rating of the battery. Usually there will be 2 different numbers, the Cranking amps, and the Cold Cranking amps. This is the only determining factor you have at your disposal when selecting an automotive battery. Yes, amperage IS current rating, but when talking vehicle batteries, the CA and CCA are the only capacity ratings you have to go by, and the only difference in the two is temperature.The amperages are still calculated using Ampere-Hours, as with all current, but you use the CA and CCA ratings to determine the correct capacity for your application. Automotive batteries aren't designed to be discharged and recharged, only to supply cranking power for the starter motor. Once the vehicle is running, the charging sys takes over and runs all electric components. Thus, a standard Ah capacity rating is not used to determine capacity as you are defining it, only CA and CCA. You still use these ratings to figure capacity,however.
A 650 CA battery will still require 650Ah to chargefrom a completely discharged state.
This may sound like a whole different direction than what this thread was started on, bit it has everything to do with the OP's question. I'm trying to suggest ways for him to recharge his high capacity batteries at the field without leaving himself stranded, not get into a pissing contest with someone who doesn't (or chooses not to) understand my point.