Full charge fails load test?

[Geo-TH,In]

I have a 4 year old delco battery, the original battery in my 2007 GMC. The last oil change the dealer said my battery failed the load test, however the truck starts just fine. Dealer wants $169 to replace the 600 cca battery 6 year battery. Went to Auto Zone for a second opinion. They too said the battery has a full charge, yet fails the load test. They want $95 for a 700 cca 3 year free replacement and additional 5 year pro-rated battery 8 year total.

How can a battery have a full charge and fail the load test, unless the battery came from the factory and it wasn't a 600 cca battery?

I'm going to carry a spare battery and jumber cables. Will replace the battery when it won't start the truck. Also carry my AAA card and cell phone.
George

 

[old]

Very simple a load test, test it for holding up to a load for X amount of time and if it does not do so then yep it fails the load test. Yes it may still start your truck ok but when the day comes that it needs those extra amps for a longer time it will let you down

 

[Allan in NE]

I'd go ahead and drop in the $95 dollar model. It will fail you when it's -20° out. :>)

Allan

 

[Revredneck]

I agree with the others. You should go ahead and replace it before it leaves you stranded. I've seen lots of batteries do like yours, and a load test is the most reliable way to test a battery. Good Luck and God Bless

 

[guido]

Hello George March,
Battery load test goes like this:
Load applied is 1/2 of the battery CCA. Hold for 15 seconds read voltage. For a bettery to pass the test, it has to have a minimum voltage of 9.6 volts at the end of the test. The battery HAS TO BE FULLY CHARGED BEFORE THE TEST.
A bettery is not considered fully charged, just becouse it starts a vehicle.
In your case, even though it failed THEY test, the battery is still crankig the engien O.K.
How many amps did they load the battery with?
How many times I see a guy bring in a battery to the auto store, ask the battery to be tested, because it won't start the car.
The genious behind the counter puts a lod test on it!!!!!!!!! It fails every time???
BATTRY HAS TO BE CHARGED FULLY FOR THE TEST TO BE VALID!
Guido.

 

[MSM]

With all the electronics and computers in the newer vehicle,that require a minimum voltage to energize, it is important to keep a good battery in it. While it may still crank over OK, there is a chance that the starter will take all the available voltage, not leaving any for the electronics.

 

[John T]

Okay heres the deal:

1)Just because a battery fails a "load test" that obviously dont mean it wont start your truck BUT YOU KNOW THAT WELL DUHHHHHHHH

2) A load test is still a good real world valid test indicating the batteries energy storage and energy delivery capacity. Id expect the battery be fully charged (they can test each cells specific gravity at no charge likely) for a good load test ya know........

3) I wouldnt be surprised if an older battery or one thats been abused or not charged and maintained properly would flunk a load test or at least not pass with the flying colors as it would when new..... ID CALL THAT TYPICAL

SOOOOOOOOOO WHAT TO DO if it were me and I wanted better insurance my truck would start this winter in extreme cold temps ID INVEST IN A NEW BATTERY AND ID USE MORE LIKE A 700 AT LEAST UP TO A 1000 CCA

HOWEVER as long as the old one is starting the truck and all is operating correctly, sorry I just dont see it as any emergency situation requiring you run out and buy a new battery today. Id also carry jumpers

Nuff said, now its your truck, your risk, your money and your call

John T

 

[Stephen Newell]

It sounds like the battery may be sulfated. It would show a full charge but with it full of sulfate crystals it can't deliver the amperage. I've never tried it but I've seen reports of people extending the life of a battery by reconditioning one with a Epsom salt solution. I don't know the history of how you use your truck but if any vehicle sets for months at a time without being used sulfate crystals grow on the lead plates. This is especially a problem with tractors this time of year. I try to put mine on a battery charger once a month when not in use.

 

[LJD]

All full charge means is that each cell is around 2.15 volts. Tells you nothing about how long that battery can supply the test amps. Old batteries often put out the rated amps but for less time.

 

[El Toro]

Use a hydrometer and see what the specific gravity is in each cell. If they all read 1.260 I wouldn't replace it. If one cell is a lot lower I would replace it. I was told the last time I had the car serviced my battery was weak. I've been carrying a spare battery in the trunk with wrenches for the last 4 months. It's 10 years old and is one of Walmart's best battery's. Check your charging voltage using a volt meter across the battery terminals. Should see around 14 volts. Hal

 

[Geo-TH,In]

I drive my truck every day. Just measured battery voltage after it sat all night, 12.55V. Can't do anything with battery, maintance free. Can't measure the specific gravity of cells.

The crazy thing, in MHO, is how can a battery with a full charge, meaning it has all the electrons backed in it, fail to produce those electrons? You couldn't fully charge a battery if the plates were coated. I fully understand what load test is and cca. The term fully charged should not apply here. That was the reason for this post.

I think I'll connect my voltmeter to the battery and keep an eye on the Cranking Voltage. The starter is the ultamate load tester. Thanks for all your opinions.
George

 

[Jon Hagen]

"How can a battery have a full charge and fail the load test, ??"

A good portion of the battery plate material (possibly 30%-50% is no longer avalible to produce cranking amps, likely because of material shed off or plate sulphation.
What remains may be fully charged, but is only 50% -70% of what was avalible to produce cranking amps when the battery was new.

 

[B-Mod]

(quoted from post at 13:04:26 11/19/11) I drive my truck every day. Just measured battery voltage after it sat all night, 12.55V. Can't do anything with battery, maintance free. Can't measure the specific gravity of cells.

The crazy thing, in MHO, is how can a battery with a full charge, meaning it has all the electrons backed in it, fail to produce those electrons? You couldn't fully charge a battery if the plates were coated. I fully understand what load test is and cca. The term fully charged should not apply here. That was the reason for this post.

I think I'll connect my voltmeter to the battery and keep an eye on the Cranking Voltage. The starter is the ultamate load tester. Thanks for all your opinions.
George

The plates are now coated, dead, making the battery in effect a smaller battery. Kinda like a "d" cell battery vs a "aaa" battery, they both produce 1.5 volts, but the capacity is less in the "aaa" battery.....

 

[buickanddeere]

I agree with the other answers.
Install the highest CCA battery that will jam into the battery box.

 

[Wilson]

hello old friend!! few montha ago grand daughters yucon would not start just after running well, got gas and NOTHING. gUESS WHO GOT CALLED?? was at wal mart so pushed her to back and new battery. I took old one and replaced core with total junk battery. Drilled holes in top, added H2O charged, then taped holes with gorilla duct tape. Put in whay we call the snowmobile ( 97 ford 3/4 ton 4x4) It has been working fime for months now. I did put desulfate small charger on for 4 days. Desulfate charger has a frequency to break sulfate. I am not sure im saying it right as a good friend worked my physics assigmnents when expand teaching certificate. Thanks my friend!!!

 

[LJD]

Hey . . that's what I use to test my maple syrup when I'm cooking sap. Refractometer that cost 10 times what it's worth.

 

[Tony S.]

I've got 2 tractors, batteries never gave a bit of trouble, both failed completely on the first cold days this fall. Both about 5 or 6 years old.

 

[Geo-TH,In]

Bill, Where do you get a Desulfate charger? I've heard of people with golf carts talk about them. Do they really work? I also heard of a guy blowing up a battery trying to drill a hole in it. The sparks from the brushed ignited the hydrogen in the battery. Be careful!
George

 

[Jon Hagen]

"Where do you get a Desulfate charger?"

I have two of these little BatteryMINDer charger /maintainer / desulfator units from Northern Tool.
They do a good job keeping my farm equippment batterys in good shape during the idle season.
BatteryMINDer.

 

[Stephen Newell]

I think the term fully charged probably goes to how smart your charger is. I have had battery chargers that would say fully charged when the battery is bad. I have a cheap black and decker charger now. It won't do anything if it detects anything wrong with the battery, even if it's just dead from leaving the lights on overnight. I have to jumpstart the vehicle and run it for a while before I can use the charger on it. I don't like it because it puts an unnecessary strain on the altenator.

 

[greygoat]

I have a magazine called "Auto Restorer" for a
few months it"s been running a series on battery
chargers, partcularly about those to eliminate
battery sulfation. They tested a lot of them on
old batterys that wouldn"t hold a charge anymore.
One that was a"recommended Buy"was"batteryMINDer"
www.batteryminder.com
www.autorestorermagazine.com

 

[barnE]

Old time test was fully charged battery, according to hydrometer. Hook voltmeter across battery(12 volts reading), crank engine and reading should not go any lower than 9 volts. Have not tried in about 20 years. Dave

 

[Wilson]

the battery minder is what I have

 

[Anonymous-0]

I would check all connections, including ground wire, for a case of the greenies, in the copper wire. Then I would keep a spare battery, and jumpers, or at least a boost battery pack, in the truck. Why spend the money till you have to?

 

[36 Coupe]

I opened up an old 12 v battery and found one cell had lost 1/2 its plate material.Jumper cables are a last resort.When gray water comes up in the hydometer the battery is on the way out.