2002 S60: Are In-Store Battery Tests any Good?

Post by **coflynn** » 24 Jul 2014, 17:46

Alright - my battery is just over 3 years old. Lately it's been giving me a lot of trouble - basically just dieing after seemingly random amount of time. The alternator regulator is new last year & I've measured that there is no parasitic current draw on the system. I did have a test done of the alternator that it was charging the battery OK a few months back (had died & road-side did that, although they couldn't do the battery test as charge was too low).

It's died on me a few times now - several times after just sitting while I'm in a store for around 1 hour, and it was just driven before that.

The thing is I took it into a store here (Canadian Tire) that has one of those small hand-held clip on analysers. They claimed it was perfect - they measured over 700 CCA @ 12.62V but it's only rated 690 CCA, and talked me out of buying a new one.

Thus my question - are there failure modes those analysers wouldn't catch? They obviously aren't doing any sort of long-term checks, but I wanted to see if people have had those tests appear good despite other issues with the battery.

Thanks!

Post by **abscate** » 24 Jul 2014, 19:54

If you let a lead acid battery sit discharged for a length of time, like a week , you can chemically kill it so that it have about 5 seconds of crank capacity

CountryBum-kin · Post by **CountryBum-kin** » 24 Jul 2014, 20:22

3 years is about the end of the average store battery. There are variables that will sway one way or other, such as alarm, A.C. blower, etc, CCA.

KurtL · Post by **KurtL** » 25 Jul 2014, 00:20

I had similar issues. I must have had a wonky cell on a fairly new battery that one particular tester wouldn't pick up. We tried a couple different testers and got one anomalous reading we couldn't repeat.
After replacing the battery no more issues.

draser · Post by **draser** » 25 Jul 2014, 06:26

There are a few simple tests that you can do to determine battery and charging system condition. It only takes a cheap digital multimeter. A fully charged battery should read 12.6 volts with engine off, and no less than 9.6 volts during crank. The charging system works when you read 14.4 volts across with engine running. Check battery posts to be clean and àlso the cable clamps. Smear some grease on both and secure tight.

Post by **coflynn** » 25 Jul 2014, 10:28

Thanks for all the information! Charging system seemed OK so I got a new battery anyway from costco, will update this in a few weeks with final results.

Post by **coflynn** » 30 Jul 2014, 08:39

Quick update - indeed seemed to be the problem. So even if the in-store test claims you're battery is 'better than new' it may still be the issue.

draser · Post by **draser** » 30 Jul 2014, 11:10

Hard to say not knowing how their test is done. However, their test results, 700cca @ 12.6v does not look right. That's because even for a fully charged batt the crank voltage is 11.6v, that's what you'll see in the car. So, it looks like they don't apply same load to read cca.

bugeye · Post by **bugeye** » 30 Jul 2014, 17:09

Once upon a time I had a known good battery fail to start the car when the car had been driven an hour earlier and did not exhibit any symptoms of a problem. Car was absolutely dead. Battery terminal connections were clean. Found corrosion between the copper wire and battery terminal. Replaced red wire to starter.

Post by **coflynn** » 30 Jul 2014, 18:57

Hello,

The test was done with an EXP800 (they gave me the printout), see http://www.midtronics.com/shop/products ... ed-printer .

It was easy to see from the unit it wasn't going to be applying that high of a current test, as the leads are fairly small. It doesn't specify specifics in the unit manual that I glanced through out of interest, so I assume it's extrapolating some smaller test...