Car Battery Models: A Practical Side-by-Side Comparison Guide Choosing between two car batteries shouldn’t take all afternoon. The fastest path is to compare fit first, then chemistry, then the metrics that actually predict real-world durability, and finally price and total cost of ownership. Start by matching group size and terminals to your vehicle, choose the correct chemistry (flooded, AGM, or lithium) for your duty cycle, then weigh cold-cranking power, life/heat resistance, and reserve …