Battery Basics The average lifespan of a battery is between three and five years. If your car is over three years old and still has the original battery it's probably time to purchase a new one. It’s better to take initiative and replace it before it dies than to wait for that fateful and probably most inconvenient day. The condition of your battery depends on the cell plates inside. Sulfuric acid reacts with lead in the cell plates producing an electric current. As batteries age, sulfate begins to accumulate on the cell plates. Accumulated sulfate restricts the amount of current that passes through a battery. A new battery has clear cell plates that are capable of transmitting a strong current. A battery that is three years or older may have substantial sulfate residue on the cell plates.
Some batteries accumulate sulfate faster than average ( between one and three years.) This occurs when the battery is frequently fully discharged. Fully discharged could mean leaving your lights on or making frequent short trips. The lifespan of a car battery can be significantly decreased if the battery has remained discharged for a long period of time. A good example would be the battery in a classic car that has sat in storage for a few years. This is why removing a battery from a vehicle in storage (or used infrequently) makes sense.
Extreme heat is another cause of premature battery failure. Batteries in hot arid places like Arizona and New Mexico typically have a shorter lifespan than those in cooler climates. The water inside the battery falls below the level of the cell plate terminals disallowing current to pass.
Keys to Buying If a new battery purchase is in your future, understanding the different components of a battery can be useful. Consult your owner's manual for factory specifics about your battery before proceeding.
Actual Group Size Group size refers to the physical dimensions of a battery and the placement of terminals. Check your vehicle’s owner’s manual for specifications. Improper group sizes can lead to loose battery connections and placement. Battery retailers will stock group size manuals to help consumers determine their needs.
Cold-Cranking Amps (CCA) This number refers to a battery’s ability to start a car in cold weather. Cars struggle to start in cold weather because the engine oil is less viscous (fluid) and creates slower chemical reactions. The cold-cranking amps indicates how much current the battery can produce for the car's starter at zero degrees Fahrenheit. The measure CA (Cranking Amps) denotes current strength at 32 degrees Fahrenheit. Refer to the CCA figure rather than the CA figure when determining battery strength.
Reserve Capacity & Age Reserve capacity isn’t typically promoted or stated on the battery. However, it is an important factor defining how long a vehicle can run when an alternator failure occurs. The figures are typically stated in the product manual and not on the actual battery. Age is a major factor when it comes to battery purchase. It is safe to assume chain stores have a higher turnover rate of batteries than a small business mechanic. Do not buy a battery older than six months. The date can be found on the battery or its label. The first letter and digit indicates the date of production. The letter refers to the month with “A” meaning January. The digit refers to the year with “1” meaning 2001. As a result, a code of “C8” would indicate that the battery was produced in March 2008.
Warranty Warranties always appear to cover more than they actually do. A battery warranty should be on the battery label and consists of two numbers. The first number is the full warranty number and the second is the free replacement period. Clearly understand the difference between the two numbers. If the battery fails after the “free replacement” period expires, you will be credited on a pro-rated basis.
With batteries the CCA, reserve capacity, age, and warranty can be highly variable across brand names.
