I have a somewhat general question...If two batteries in a circuit are connected in parallel with no resistors or capacitors in between, would you find the total current by just adding them together, or would you have to add 1/V ?
The overall voltage is the same as the rating for any single cell. That is assuming that all cells have equal voltage rating! Yes, the max total current is the same as the sum of current provided by individual batteries. Therefore you get a higher ampere-hour rating.