Can I use 2 or 3 lower cranking amp batteries to crank a bus instead of 1 battery that would have enough cranking amps alone? Would 2 950 cranking amp batteries in parallel equal 1900 cranking amps?
As long as the batteries are fully charged and in good shape, by placing two 950 CA batteries in parallel, you will get 1900 CA ... you are exactly right. Just understand what you're doing when you put them in parallel and you'll have no issues. If you put the two batteries in series, you'll still only have 950 CA, but you'll be pushing 24VDC worth of juice, so understand what you're doing. Also, when you do put these in series you want to ensure you have cables on them which will handle the power. You need cables between the two batteries which are of the same gauge or larger than what is used on the bus. If you don't, the smaller cables can heat up and cause issues.