Let's face it, if your car battery is dead or even weak, you're not going anywhere. It's the leading cause of starting trouble. A perfectly healthy battery in 80-degree weather will have only half of its output when the thermometer dips to zero.

Batteries are rated by cold cranking amps (CCA rating), indicating the battery'spower. The reserve capacity rating (RC) indicates how long you can run car accessories and still have enough power to start you engine.

Since starting a car in cold weather can take up to twice as much current to turn over a cold engine, cars in colder climates would benefit from a higher CCA rating. Check your owner's manual for the original equipment manufacturer's (OEM) minimum requirements needed for your car; select the battery adequate for you needs. Buying one with an excessive CCA rating may be a waste of money. In every situation, more RC is better. The size and number of plates in a battery determine how many amps it can deliver. By having more and/or large plates, you can increase the normal life of the battery. This is what distinguishes a 3-year from a 5-year warranty battery.

Battery manufacturers build their products to an internationally adopted Battery Council International (BCI) group number based on the physical size, terminal placement and terminal polarity. BCI and the battery manufacturers offer application guidelines that contain the OEM cranking amperage requirements and group number replacement recommendations by make, model and year of car and battery size, CCA and RC specifications. When buying a car battery, it's best to shop where knowledgeable salespeople can assist you in selecting the right size and requirements for your vehicle. We know our batteries and can do this for you. We go to clinics sponsered by battery companies such as Interstate Batteries to stay on top of the latest developments in batteries.

(The inside of a Battery)
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Finally, compare warranties. Most manufacturers prorate warranties based on the full list price of both the bad and the replacement batteries. If failure occurs halfway or more through the warranty period, buying a new one on sale may cost less than paying the difference under a prorated warranty.