Depending on power, size, and quality, prices for a replacement car battery range from about $45 to $250. Your local dealership, auto parts store or automotive service center can check your current battery or hook you up with a new car battery.

If you go to the dealership, you might want to schedule an appointment to minimize the wait.

The average car, truck or SUV battery should last six years. But there are a lot of key factors that can change that:

• extreme temperatures
• humidity
• heavy accessory loads
• frequent towing

In those cases, you may only get 3 or 4 years from your car battery.

And, of course, if you leave the lights on overnight or the trunk ajar, you might wake up with a dead battery, no matter how new it is. Luckily, some newer cars have a failsafe to keep this from happening.

The battery in your vehicle is there to provide a jolt of electrical energy to start the engine and to provide engine-off accessory power for a limited amount of time. Once the engine is running, the alternator takes over to power the accessories and charge the battery. Car batteries typically feature six connected cells in a lead-acid formulation, or up to 12 cells in a 24-volt system found in heavy trucks or other large vehicles.

Batteries are not “one size fits all.” There are several things to consider:

• Size:Typically based on your vehicle’s make, model and engine type, it is literally the footprint of the battery, along with placement of the battery terminals. Every battery has a slightly different terminal placement. Take care to make sure the new battery you are putting into your car, truck or SUV is the same size as the one you are replacing. It’s got to be “apples to apples”. In other words, don’t try to fit a pineapple into the space reserved for a canteloupe.
• Age:Like a loaf of fresh-baked bread, batteries are best when “fresh,” within six months of manufacture. Most batteries, like the one in your current vehicle, will have a date code to tell you this information. When in doubt, call the battery maker to decipher the date code.
• Cold Cranking Amps: Can this battery start your frozen SUV at 0 degrees Fahrenheit in the dead of winter when the oil is as thick as molasses? The higher the Cold Cranking Amps (CCA) rating, the better the battery’s starting power. The rating refers to the number of amps a 12-volt battery can deliver at 0 degrees F for 30 seconds, while maintaining at least 7.2 volts.
• Reserve Capacity: In the case of an alternator failure, the Reserve Capacitywill give you an estimate of how long your car’s battery will be able to run on battery power alone, without the help of the alternator.

Speaking of the alternator, a faulty alternator can cause your battery to not recharge properly. Your dealer’s service department or your local auto repair center has the equipment to check the health of your vehicle’s alternator. We recommend having it checked every time you change your oil.

A confident do-it-your-selfer can replace a vehicle battery. Start by checking your vehicle owner’s manual for the battery’s proper size and location. Find the positive and negative posts. The positive post will have a red plastic cover over it. Look for a + sign stamped onto the battery or printed on a nearby label. Loosen the negative (-) terminal bolt and remove the cable. Be sure not to touch the positive post. Once you loosen the bolt, use a terminal puller to remove the cable. Repeat the sequence with the positive post.

Now remove the clamp or retaining system that keeps the battery in place. Carefully lift out the old battery. Look for any corrosion on the cables and remove it with a wire brush or terminal cleaning tool.

Drop in the new battery so that the positive post lines up with the red cable. Secure it with the battery retaining clamp that you removed earlier. If the battery has anti-corrosion washers, put them in place now and use a thin layer of anti-corrosion grease to prevent buildup. Tighten the positive cable and then do it all over again with the negative (-) black cable.

Make sure the battery is secure and congratulations: you’ve replaced your car’s battery!