Buying a Battery

Automobile batteries will usually last as long as they're supposed to unless neglected. If your car came to you new off the lot then there is no mystery involved in when and what kind of battery to choose when the time comes. The battery under the hood of that mint condition 1991 Dodge Colt Vista Wagon you just picked up off eBay may be of more uncertain origin. Worse is that your car might not even have the right battery for it. New car or used, the best time to choose and buy a new battery is before the one presently under the hood gives up all together.


The battery will tell you when this about to happen. Unless you left the lights on or there is an electrical short, automotive batteries will not generally suffer from sudden death. The classic warning sign of impending battery expiration is the starter laboring to turn over the engine in the morning. This laboring will slowly sound more difficult until nothing but a few sad clicks come from under the hood instead of the usual joyful cranking.

Battery Blundering
A common and expensive do-it-yourselfer battery blunder is to assume the battery has quit altogether and replace it, only to discover a brand new but dead anyway battery the following morning. If your vehicle seems to be laboring to turn the starter in the morning then first check the charging system. Many auto parts stores now have portable diagnostic equipment they can roll out to help you in this task. If the charging system checks out then it's time to run a battery load test to determine if the battery needs maintenance or outright replacement. Also check your shorts. An electrical short can drain battery power while you sleep. A frayed wire grounding out against the frame or body of the car can create a circuit and drain battery power. A spent starter or starter solenoid can also mimic a dead battery. If battery replacement proves the best option then making the best choice in batteries depends on several different factors.

Group Size
The first consideration is choosing the correctly sized battery for your vehicle. Batteries are divided into what are called group sizes by automobile manufacturers to standardize battery sizes and prevent any square peg, round hole situations underhood. Fitment is an important concern. A perfect fit keeps the battery snug in the battery tray and working with the factory battery hold down system. This prevents battery damage by keeping vibration to a minimum. A battery that is too small can rattle around in the battery tray and suffer short life. With the next step of the battery buying process comes the realization that there is more than one battery in the display in the size required—but for some reason they have different prices.

Cold Cranking Amps - CCA
Before your inner cheapskate prevails, remember that a battery must have enough power to turn over the engine. This cranking power is measured in Cold Cranking Amps [CCA], and is the standardized measured amount of cranking power that a given battery can deliver at zero degrees Fahrenheit. CCA is of particular concern for those who live where winter temperatures can dip below zero. Engine and transmission oil becomes thick as molasses at these temperatures. Turning over the engine will sometimes require more CCA than measured at zero degrees. Freezing one's behind off on a cold winters morning is the wrong time for a lesson in CCA capability. Select a battery with a higher than required CCA rating if the vehicle is operated in colder than zero degrees climates. Never select a battery that has less than the CCA required by your engine. A few extra is better than too few.