Car battery in new car

Though battery problems are often associated with cold weather, Consumer Reports magazine says heat is a bigger enemy of car batteries and will take a bigger toll on performance and reserve capacity. The magazine recommends that vehicle owners in hotter parts of the country have their car battery tested after two years of ownership and then every year after. Those who live in colder areas can wait four years to test performance and capacity, and then every year after.

“Heat kills batteries,” according to John Banta, a Consumer Reports project leader and part of the team that tests batteries for the magazine. “Many times in cold climates your battery fails to start your car on a below-freezing day. The reason this happens is that the heat of the past summers has weakened your battery. When you use it in the cold, the starter requires more electrical current to turn over the cold engine with its thickened oil.”

Testing a battery’s performance and reserve (or amp-hour) capacity is not just a matter of seeing whether it will hold a charge (or checking the electric eye found on some batteries to see if it is green), so testing is best done by an auto technician.

A belt that isn’t cracked or frayed may look like it’s in good shape, but grooves on the hidden side may be worn enough that the belt slips on the pulleys that drive the accessories. That will cause problems in systems that rely on the belt to keep things humming. For example, a slipping drive belt may cause the alternator to work intermittently or at reduced power, and the battery won’t get fully recharged as a result, perhaps triggering a warning light.

Another sign of a worn belt is a squealing noise under acceleration. That could indicate that the belt is slipping because of wear, a belt tensioner is loose or a pulley is out of alignment.

Most modern vehicles use belts made from ethylene propylene diene monomer, a synthetic rubber that lasts longer than older types of engine belts. Most belt manufacturers estimate the typical lifespan of an EPDM belt to be 50,000 to 60,000 miles, and some say it’s more than 100,000 miles. However, it can be hard to tell how worn one is with just a visual check because EPDM belts are less likely to crack or lose chunks of rubber than other types. They should be inspected by a professional.