Battery test?

[Rolla07]

So over the weekend I had AAP run a test on my battery. The result was the following:
Voltage: 12.93 volts
Measured: 436 CCA
Rated: 550 CCA
Temperature: 63 F

Based on their testing they recommend replacing it. Now if the battery still has 436 CCA, it should still work fine shouldn't it? I didn't drive the car for a couple days last week and it was about -5 degrees celsius and it wouldn't start. If it does need replacing as they indicate, would that mean my car uses more than 436 CCA to start up? The reason I wonder, is because some batteries group 35 or others that they say will work have only 500 CCA, so it makes me wonder if I should find the highest CCA available and replace it? What are your thoughts? Would you replace it? The last time I tested it was last year same time, and it tested good. Advice, suggestions and feedback on the results is appreciated!

 

[eljefino]

I worked at a tire shop and we ran the midtronics tester. Likely what AA uses. Most of them generate a little thermal paper report-- I suspect you did not get this report. The report will read "recommend replacement" but you got a parts store interpretation. The warranty threshold was 50% of rated CCA. By that standard you should be good.

IIRC the CCA is what it can supply without dipping under nine volts for 30 seconds. So it could "peak" a bit more.

Check your starter for a rating, my saturn was 1.2 kW, or 100 amps at 12 volts, or, realistically, 150-ish in real life. The starter will only draw what it needs, if it needs too much the battery voltage will drop some more. If volts drop too much crank speed is too low or non existent and you get a no-start.

 

[Rand]

CCA is measured at 32f

so likely your battery is closer to 350-400CCA.

by it wouldnt start what do you mean? ticking noise? totally dead battery or what?

You can get an autocraft gold with the online coupon for pretty cheap.

 

[eljefino]

Originally Posted By: Rand
CCA is measured at 32f

so likely your battery is closer to 350-400CCA.


The midtronics tester (if used) uses an IR gun to measure battery case temp and then does math to correct it to 32'F.

 

[Rolla07]

Yes I got the printout from AAP. When I tried to start it was clicking sounds. I got it boosted and has started everytime since... although it has been in the +'s tempwise..

 

[Rand]

Originally Posted By: eljefino
Originally Posted By: Rand
CCA is measured at 32f

so likely your battery is closer to 350-400CCA.


The midtronics tester (if used) uses an IR gun to measure battery case temp and then does math to correct it to 32'F.


While true
That assumes the AAP counter-monkey did it right. I had them test mine and they got 2 different answers.

I found its just easier to bring mine from home when buying a battery.

I got a bad battery a couple years ago.. now I don't go without it.

 

[Rolla07]

Yeah.. who knows if it was done right.. I'm having my buddy at the dealer test it again tonight to see if its a similar result.

 

[Donald]

The high end Midtronics battery testers compensate for temp. But they all do not.

I have a Solar battery tester and they recommend that the tester's clamps go directly on the battery post, not on the clamp. It does make a difference, not huge, but a difference.

Of course the best battery tester is a carbon pile tester adjusted to 50% CCA. But the battery needs to be fully or almost fully charged. Thus why the Midtronics testers are used.

 

[Quattro Pete]

Rand, how does that analyzer know what the rated CCA is for a given battery? Or do you have to program that in?

 

[The Critic]

The internal resistance value is also a significant factor. The midtronics tester is probably testing for this as well.

 

[WobblyElvis]

Test the charging system then proceed. It is not good for a battery to ever be allowed to go dead. This battery has been in a condition that would not start the car and it "failed" a test. The temp is about to drop. I think this is a no brainer. Replace the battery or get ready to lift the hood in a blizzard. Your choice.

 

[Quattro Pete]

Originally Posted By: Rolla07
I didn't drive the car for a couple days last week and it was about -5 degrees celsius and it wouldn't start.

How old is the battery? Was the battery fully charged prior to this? If not, charge it up and see what happens. If again you can't start the car at -5C, replace it.

 

[4wheeldog]

If it is the original battery, replace it, without question. If the battery is less than 3 years old, it is probably fine, and you might want to clean your terminal connections.

In between those two possibilities.......Worth another test, when you are certain that the battery is fully charged.

 

[Rolla07]

Originally Posted By: Quattro Pete
Originally Posted By: Rolla07
I didn't drive the car for a couple days last week and it was about -5 degrees celsius and it wouldn't start.

How old is the battery? Was the battery fully charged prior to this? If not, charge it up and see what happens. If again you can't start the car at -5C, replace it.



I dont know if it was fully charged.. I suppose unless I ran a test on it.. It just wouldnt start after 2 days of sitting outside.

 

[StrangeBrew]

Originally Posted By: Quattro Pete
Rand, how does that analyzer know what the rated CCA is for a given battery? Or do you have to program that in?

If it is like the solar, you have to enter it. You also have to select the battery type (lead acid, spiral wound agm, etc.)

 

[Quattro Pete]

Again, how old is the battery?

 

[Rolla07]

Originally Posted By: Quattro Pete
Again, how old is the battery?


Original battery. so Id say 7-8 years.

 

[Nick1994]

Your battery is 7-8 years old. Replace it already. Here in AZ it's not often you hear of a battery going over 3 years. My car gets it's battery from the dealer and dies every 1.5-2 years. Consider yourself lucky and go buy a new one.

 

[Quattro Pete]

Originally Posted By: Nick1994
Consider yourself lucky and go buy a new one.

Agreed. This battery owes you nothing at this point. Get a new one, unless you don't mind getting stranded at the most inopportune time and place.

 

[HerrStig]

The proper grade synthetic oil puts a smaller load on the starter motor. I'd use that AND make sure all the terminals in the starter circuit are clean including the bonding between wires and clamps, and the body ground. If you lived in Florida your battery would probably get by. In the cold you guys put up wiith I'm not sure I'd risk it. Are you sure you don't have a trunk light stuck on or some other parasitic draw that doesn't normally occur. It would also be wise to test the alternator, the classic "make the rent this month" repair shop game is to sell you a nice high profit battery and when you come back in a few days sell you the alternator you really needed.