Battery rated 550 CCA tested at 409 CCA. Problem?

[barlowc]

I was at my dealer this evening for a pre-winter inspection. (i.e. battery/alternator/starter check, top-off wiper fluid, etc.) It was free, so why not?

Anyway, the Service Advisor said that everything checked out fine, but there was something on the diagnostics printout that I questioned. The battery is rated at 550 CCA but measured at only 409 CCA.

He said a brand new battery rated at 550 CCA would test at that, but not a perfectly fine 3 1/2 year old battery like is in my vehicle. Does that sound right to you guys?

The car starts at the push of it's button without any hesitation or extra cranking. But with the cold weather just around the corner here in Southeast Michigan, I certainly don't want to risk a battery-related problem.

 

[spasm3]

Was the temperature of the battery , the same as the cca rated temperature? IF it was colder there may be no problem.

 

[daves87rs]

Umm....my Cobalt tested 471CCAs when it needs to be at 600CCAs.


I was just replaced by an Autocraft Gold this morning....

 

[barlowc]

Originally Posted By: spasm3
Was the temperature of the battery , the same as the cca rated temperature? IF it was colder there may be no problem.

The diagnostic printout shows the tested temperature as 63*F. I don't know what the CCA rated temperature is.

 

[JHZR2]

Makes good sense.

I=E/R

Assuming voltage is full charge, 12.7V, then 550=12.7/0.023, resistance is 0.023 Ohm.

409=12.7/0.031, so resistance is 0.031 Ohm.

So your battery's internal impedance has grown by 50%. Generally EOL is determined by being at 200% of BOL impedance.

Id say youre good.

Doesnt mean other things cant kill your battery!

 

[daves87rs]

In Michigan, I don't take chances...crazy weather here is hard on batteries anyways...

 

[barlowc]

Here's the diagnostic report:

 

[wrcsixeight]

From the moment the battery is filled with Acid, it is slowly losing capacity and cranking amps.

The rate at which it loses power is directly related to how it is treated.

Alternators, as with most every single battery charger out there do a very poor job at returning a battery to actual 100% capacity.

A battery can only accept a little current as it nears full charge. Don't think your 200 amp alternator can return it to 100% any faster than a 50 amp alternator, unless the battery was discharged to 50% and the engine was kept at higher rpms during recharge.

The closer you can keep a battery near or at 100% state of charge, the longer it will last. Weekly use of an plug in charger will work wonders for battery life, especially if you are one to use battery power with the engine off, and do short trips exclusively.

 

[pcoxe]

I was having some intermittent electrical problems with my Trailblazer, which pointed to the ignition switch. The dealer insisted I needed a new battery because their $4000 testing machine said it was down to "only" 450 amps. My $20 Harbor Freight tester said it was still good. I made them replace the switch and leave the battery alone. A year later, still on the same battery and no more electrical problems. All batteries gradually lose power over time. That's why higher CCA replacement batteries have longer warranties - it takes them longer to wear down to the point where they give trouble. Sure, I'll need a new battery one day, but for now this one is still working fine.

 

[Radman]

Michigan roads beat up the lead plates and the severe temps don't help when the carbon pile test is applied. I would call the battery good and not worry about it until it fails. Don't fix what isn't broken unless you have money to burn.

 

[chubbs1]

I strongly agree with the others who say your battery is absolutely fine. JHZR2 put it into the pure language of mathematics. If you do have a plug in charger that would keep the battery maintained longer, but that aside you are still OK.

 

[JimPghPA]

According to the web site "Bowling's Automotive Battery Cold Cranking Amps Temperature Adjuster":

The CCA is rated at 0 degree F

If the battery was at 63 F a good 550 CCA battery should have “CCA = 867, a 57.6 percent increase. So your 550 CCA battery that tested at 409 Amps shows less than half of what it should be.

If you enter the CCA of 409 Amps at 63 F, then at 0 F that battery will have CCA is 260, a -36.5 percent change of the 409 CCA , and 260 / 550 percent of what it should be at 0 F.

If you enter the CCA of 409 Amps at 63 F, then at -10 F that battery will have CCA is 223, a -45.5 percent change of the 409 CCA, and 223 / 472 percent of what it should be at -10 F

If you enter the CCA of 409 Amps at 63 F, then at -20 F that battery will have CCA is 183, a -55.3 percent change of the 409 CCA, and 183 / 387 percent of what it should be at -20 F

BTW, - 20 F was the coldest day that I remember here in Pittsburgh Pennsylvania and that was back in January of 1992.

 

[JimPghPA]

One of the questions is what was the temperature of that battery, not the temperatur of the ambient air?

If that battery was at 63 and it only had 409 CCA then I would think it is toast. There would be no way it would make it through the winter.

 

[JimPghPA]

Did their machine adjust the CCA for what it would be at 0 F? If it did that, then your battery is not that bad. But if the 409 amps is what it is doing at 63 F then it is bad.

 

[javacontour]

Looks like the test said it needed a charge, so maybe the battery is not fully charged, skewing the test.

I just replaced the battery in my 03 Protege5. Probably the same battery, a 550CCA Group 35. I think it was producing ~350CCA when tested yesterday.

I just used code ES123 at Advance Auto and got the 640CCA battery for $79 + tax after I returned the core. I think I have the rotation for 4 cars to buy a battery every year now. Fortunately, they all take group 35. How did I manage that?

 

[Quest]

Internal resistance increase (due to usage, time, etc.) is a normal affair in lead acid storage battery.

So, JHZR2 is correct.

I wouldn't worry about it so much so long as it still cranks fine in the coldest winter morning and still holds it's charge. The first sign of slow cranking/unresponsiveness is the time I'd change it out with a fresh new unit.

Q.

 

[Vikas]

Why did the test said "it needed a charge"? I would think that if the car electrical system is working correctly, the battery test should not indicate that.

 

[HerrStig]

My experience with modern "mantainence free" batteries is that they will fail without giving a lot of warning. I don't want to suggest replacing batteries when they are still working OK, but the notion that batteries decline slowly is no longer true. Couple that with the lack of an amp meter in the car to allow you to keep an eve on things makes it harder to predict when the battery is going to quit. As batteries age, they absorb less of the charging current provided by the alternator and turn more of it into heat. An amp meter in the charging circuit will reflect that by showing that the regulator is supplying more current to the battery ages to keep it "float charged" to 14.2 after the car is started and the charge used to start it is replaced. Without that meter to watch, there is a certain amount of rolling the dice which goes on. Why no meter on modern cars? Cost, and the inability of most people to make sense out of the readings.

 

[pcoxe]

Originally Posted By: Vikas
Why did the test said "it needed a charge"? I would think that if the car electrical system is working correctly, the battery test should not indicate that.


The testing itself ran the battery down to a certain extent. It is a recommendation to fully recharge the battery before returning it to the customer.

 

[Quest]

Originally Posted By: HerrStig
Why no meter on modern cars? Cost, and the inability of most people to make sense out of the readings.


Simple! Since most NA automobile operators doesn't even know what an idiot oil light means to them (or oil pressure gauge readings), letting alone a voltmeter/ammeter readings on a car, why should automobile manufacturers spend extra $$$ on automobiles to implement those gauges/meters that owners can't understand/read?

It's a cost-saving measure I admit, but it works both ways (majority owners don't seem to care/indifferent)

Q.