Your car battery is your lifeline to a running vehicle, so if it dies, your vehicle will not be able to operate. When you are choosing your battery the two most important factors you should be looking at are the group size and cold cranking amps. The group size is the thing that defines the batteries dimensions and the placement of the terminals. Most of the cars made by one manufacturer will all have the same group size, but a different group size than vehicles from other manufacturers. The cold cranking amps measure of a battery’s ability to start your vehicle in cold weather. When your car has been sitting in the cold for a long period of time the oil thickens and slows the chemical reaction making it the hardest time for your engine to turn over. Cold-cranking amps specify how much current the battery can deliver to the starter at zero degrees Fahrenheit. These are different than the cranking amps that are measured at 32 degrees, and usually display a much higher number. Aside from the group size and cold cranking amps, you should also take into the consideration the reserve capacity of the batteries. This helps you if your alternator were to fail by showing you how many minutes your vehicle will run on the battery alone.