by Pat Goss
One of the most important parts of the car is the battery. Replacing a car battery is not as straightforward as it once was. If we take the battery out of the car, we can’t start it, we can’t drive it, we can’t even listen to the radio. So it is vital. And you know batteries last quite a long time for some folks, not so long for others. But sooner or later, every battery is going to go bad. Now, how do you go about wisely shopping for a replacement battery?
Well, for years I’ve been telling you that the one criteria – cold, cranking amps. Well, that’s still very important, because cold, cranking amps tells you the ability of the battery to do work right now. And the higher the cold cranking amp rating of the battery, the better it is for your car. But, don’t get that confused with cranking amps – CA. See, cold, cranking amps – CCA, cranking amps – CA. The cranking amps are rated at 32 degrees Fahrenheit. Cold, cranking amps are rated at 0, and the higher the temperature when they’re doing the rating, the higher the numbers. So, that CA rating may look impressive, but it really isn’t. Rely on cold cranking amps.
Now, back in the day when you had an average car, it would have a monster old big starter like this thing here. Well, these have gone away. And this is a modern starter. Now, the difference is this starter is a lot more efficient. Plus, engines in cars today have less resistance from being turned by the starter motor; they have less friction. So, this means we can modify this cold, cranking amp rating just a teeny little bit because we want to add something else into the equation. And that something else is RC – reserve capacity.
Now, reserve capacity is how long this battery can supply power without being replenished by the alternator before the battery goes dead. Now, that means on modern cars where you have a lot of computers. And believe me, they do – they have computers for just about everything, transmission computer, engine computer, air conditioning computer, lighting computers. And all of these things, and they all have memories and those memories draw power from the battery. So if you have a car that is lightly used, it sits for a long period of time; well, you want the longest reserve capacity you can get. Like, this one is 115, the battery in the car is 125; that would be a better battery for a car that doesn’t get used on a regular basis. So, here’s what you do – when it comes time to buy a battery, you’re looking to find a happy medium between the biggest cold, cranking amp rating that you can get and the biggest reserve capacity rating that you can get. And, if you shop wisely, you’ll have a battery that’ll last longer. All of these electronics will last longer and you’ll have more reliability.
And if you have a question or comment, drop me a line right here at MotorWeek.