Every year, dead car batteries are the cause of more than five million Roadside Assistance calls to AAA clubs nationwide. That’s because the battery, that black box that’s usually under the hood, is often the most neglected part of a car. During this frigid time of year, it also faces its toughest challenges.

Most people don’t realize that a battery, which is responsible for starting your vehicle, also supplies extra power when the vehicle’s electrical load (sound system, lights, defroster, wipers, cigarette lighter, GPS device) exceeds the output of the alternator, increasing the strain and making maintenance critical.

A battery’s “cell” contains a plate of lead sandwiched between plates of lead oxide, all of which is submerged in a solution of water and sulfuric acid. Since each cell produces about two volts, the average battery contains six cells to produce the juice needed for a vehicle’s 12-volt electrical system. A chemical reaction produces a flow of electrons, or electricity, as well as a flammable gas that causes the buildup of oxidation on the battery’s terminals.  This buildup can reach the point of blocking the electrical current. Keep the terminals clean of corrosion to avoid that groaning sound (and the associated stress) as your car starts on a frigid morning. You can do this by scrubbing the corrosion off with an old toothbrush dipped in baking soda and water, or you can use the wire brush tools specially made for this purpose available at auto parts stores.  Just make sure you wear rubber gloves and eye protection, and discard the items used properly.

The battery’s construction and operation also make it susceptible to the cold, which slows the chemical reactions of its components, draining it of power. To avoid this, you should buy a battery with as many cold-cranking amps (CCA) as you can afford. CCA is a measure of how many amps a battery will put out at zero degrees Fahrenheit. This extra reserve ensures you’ll have the needed power to start your car when temperatures fall well below freezing.

Also, be diligent about switching off your lights whenever you don’t need them.  Every time your battery goes dead or fully discharges, you have less cold-cranking capacity than before. Let it happen four or five times and the battery won’t hold a charge at all, making for an extra, unnecessary expense. Practice good battery maintenance and that black box won’t become a black hole in your wallet; instead, it’ll last four or five years.

And if you do get caught with a dead battery on the road, be sure to call AAA Roadside Assistance—we can jump-start your vehicle, or even replace your battery, during a service call.