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When to replace a battery

During an oil change, the mechanic ran a battery test and informed me that my battery should be replaced. It’s supposed to read 550 CCA, and instead reads 292. Do I really need to replace it now? My car is a 2007 Subaru Impreza, so the battery is about 3 years old.


If it gets cold where you live, you run the risk of the engine not starting if the temperature drops below freezing. The Cold Cranking Amps reflect the amount of amps the battery will provide to the starter when it’s cold. The lower the temperature, the less time the battery will provide the max CCA’s.

So if it doesn’t get cold where you live, not a major problem. But if it does, there’s nothing worse than coming to your car in a mall parking lot to find the battery can’t start the engine because it’s too cold. And you stand in the cold with a set of jumper cables in hand hoping somebody will stop and give you a jump. Or worse yet, you don’t have jumper cables!


“Do I really need to replace it now?”

Only if you want to have a car that starts and operates reliably.

Seriously, however, if your mechanic performed a load test on the battery and it was as weak as you indicated, I think that you may wind up being very disappointed very soon when the car does not start. Even if the battery is only 1 year old, if it is weak, then it is time to replace it.

In case your mechanic did not mention it to you, your very expensive alternator is working overtime in order to try to keep that battery charged. The result of this process is that you could well wind up destroying the alternator while you dither about whether to replace the battery.

If you are able to install a battery yourself, you will find high-quality batteries at low prices at both Costco and Wal-Mart. If you can’t do the job yourself, then an auto parts retailer like Auto Zone or Advance Auto may be willing to install one of their batteries for you. Generally speaking a battery from one of these retailers will be anywhere from $30 to $70 less than one from your mechanic or from a car dealer.

Get the battery replaced before you burn out your alternator and before you wind up stranded somewhere.

I agree…it’s about location, location, location. Be aware that if you have to face cold weather, it’s better to invest in a new battery pronto before winter. Many swear by a jumper battery as well. Can’t always depend upon someone else letting you jump start your car with their new Prius.

No need to simply accept this one mechanics test results. See if you can get a full-on mechanic to appraise your batterys health. If the 292 was accurate it would be safer to replace, would it be mandantory? not if you carry a jump pack, which should be in your kit anyway, but why complicate things if the second mechanic agrees?

Your battery has about 2/3 of it’s original capacity left…That will probably get you through another year…But if you are facing sub-zero weather and demand 100% reliability, you should replace it…

I would likely just replace it, but if money was a little tight, I would stop by my local auto parts store and ask them to check the battery.  Most will do it for free.  If it test as bad as the first test, I would have it replaced.  Consider having it done at that auto parts store, after all they helped you out. 

As noted, ignoring it can cost you a lot more and it might show up in at the parking lot at work after most everyone has already gone home.