Get a clamp ammeter and measure the cranking amps first.
Then, before dropping $2k, call me
check contact info
hmmm....I was just thinking I needed batteries for an electric car project I'm looking at.
I'll second the check the amps advise....I was doing a work project a few years ago and ordered lithium batteries becasue they had prenty of power in a small package and then learned (by switching on the switch) that they didn't even come close to the current I needed and were fried. A mess of plain old AA bateries were by far the better answer for the application.
Temp is an issue with Lithium Ion. You don't want to drain them or charge them too fast. They have different ratings on different ones. Some can put out more amps than others. The model airplane and electric heli guys have this down to a science.