Before replacing the car battery, the battery group number, reserve capacity, and cold-cranking amps should be written down. An automotive store or mechanic can advise customers on what type of battery to purchase based on the year, make, and model of the car if that information is not in the owner's manual. As long as it is the correct size, the new battery can have a higher reserve capacity and cold-cranking amps number. This may be helpful for people living in cold climates or those who want the car to be able to run longer if the alternator that charges the battery while driving stops working.