Load testing a battery when cold vs hot:

[Carnoobie]

Does it matter if its done with the car/battery hot vs cold? Will you get different readings?

Slow cranking with car/battery cold temps 0 and below. But any temp above on cold engine and no problems. Did load test on the battery (start car, then headlights and full heat method) and numbers were fine.

I asked mech to come to my house tommorow morning to test my starter, and he asked why I prefer at my place. I told him I want to test it with car cold (cause thats when i get slow cranking).

He said 1) Even if slow cranking doesnt happen all the time, it doesnt matter if you test the starter when the car is cold or hot.

Whereas another guy earlier told me it does. He said, if he cant see/hear the symtoms, he cant do anything about it.

So which is it?

2) First guy also said that he gaurentees 100% that its the battery for the SOLE fact that it only slow cranks in 0 or below temps with car cold. He said if it was the starter, it would happen all the time.

I told him I did the load test and results were fine, but he still insists its the battery. He says most likely 1 or 2 cells is dead and if i put in a new battery right now, it would fix it. But im not gonna go buy a new battery and risk it not fixing it.

The thing is, Mr Lube wont exchange my battery (still under warranty) if they test it and cant find anything wrong. They also said that it wont make any difference if the load test is done with the car/battery hot vs cold. That cant be right. He said the CCA ratings dont drop.

 

[bullwinkle]

Any chemical reaction (like in your battery) is faster with increased temperature, and of course your oil is thinner at warmer temps too. At the risk of asking a stupid question, what happens if the car is jumped with a jump box or another car when it is cold? Any improvement?

 

[NHGUY]

I would be using a tester that measures CCA,volts,and resistance,and ideally % of battery charge.You can have a supposed "good" battery but only have 60% capacity...and thats going to show up when its cold and the battery gets "smaller" and the engine gets "bigger" (the draw is more).

 

[Carnoobie]

Originally Posted By: bullwinkle
Any chemical reaction (like in your battery) is faster with increased temperature, and of course your oil is thinner at warmer temps too. At the risk of asking a stupid question, what happens if the car is jumped with a jump box or another car when it is cold? Any improvement?


So basically you will get different readings with hot battery? AHA I knew it! Guy at Mr Lube said the readings would only be different if car was jumped but not if it was cold or hot. WHICH MAKES NO SENSE?

But see, I cant get these idiots at Mr Lube to replace the battery under warranty because they say it makes no difference whether its hot or cold.

Now what about the starter? Does it matter if the car is hot or cold? Do you actually have to see/hear the symtoms when running the test like the 2nd guy said or is he full of ****?

 

[JHZR2]

impedance is lower when the battery is hot. It can make a big difference depending upon the battery size and rate.

 

[Carnoobie]

Originally Posted By: JHZR2
impedance is lower when the battery is hot. It can make a big difference depending upon the battery size and rate.


Lower impedance = better reading am I right?

So how do i get my battery swapped under warranty if i cant convince these morons at Mr Lube?

 

[Roadkingnc]

find a place with a smart tester,it will ask if temp is above or below 32 degrees and compensate. My money is on a bad battery. I see it quite often.

 

[Carnoobie]

Originally Posted By: Roadkingnc
find a place with a smart tester,it will ask if temp is above or below 32 degrees and compensate. My money is on a bad battery. I see it quite often.


I know a mech who has one and said he can do this for me in the morning but wants $60 even though hes 2min drive from me uhhh. Its gonna be -10 out, thats why he wants $60.

I dont know any place that has a smart tester.

But this should be done with the car cold anyways right? Cause if so, then ill need someone to come to my place for it. If it doesnt matter if the car is cold or hot then ill go to a place.

 

[johnachak]

If this is the first cold snap for the battery, it may have fewer CCA's than required for the car.

 

[hemitom]

Like i told you in your other post the shop doesn't know sh-t now that i see its Mr. lube, everything is much clearer . Of course temp makes a difference in testing what the [censored] is wrong with these guys.

 

[JimPghPA]

My dad had an old Buick that had a bad winding on one of the field coils, and it would crank slow when cold because the starter could not make rated torque.

So it could be be a bad starter.

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Regarding the battery. As a general rule of thumb, most chemical reaction rates double or half with each change of 10 Degree Celsius (18 Degree Fahrenheit). So in general you can expect that for each drop of 18 Degree Fahrenheit a battery can only put out half of what it could put out when it was 18 Degree Fahrenheit warmer.

So it could be the battery.

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Also, what oil do you have in the motor? I see you have over 500 post here on BITOG so I suspect you know enough to be using a 0W or a 5W as the first number for the oil in the engine in question.

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Is there any way you can up the battery capacity, such as use a jump pack, or adding an additional battery in parallel with jumper cables, and then try the cold start? If it started fine with the additional battery or jump pack that would show that the battery was the problem.

 

[yonyon]

Originally Posted By: Carnoobie

So basically you will get different readings with hot battery? AHA I knew it! Guy at Mr Lube said the readings would only be different if car was jumped but not if it was cold or hot. WHICH MAKES NO SENSE?

But see, I cant get these idiots at Mr Lube to replace the battery under warranty because they say it makes no difference whether its hot or cold.


I'm missing something here. Why can't you park the car overnight at Mr Lube?

 

[Carnoobie]

Originally Posted By: hemitom
Like i told you in your other post the shop doesn't know sh-t now that i see its Mr. lube, everything is much clearer . Of course temp makes a difference in testing what the [censored] is wrong with these guys.


Well i was arguing with the mgr at two locations today and both refuse to replace it. They said they cant if the numbers are fine and "it wont make any difference in the readings if the test is done with the car hot or cold"

Thats not true. You do the test with the car cold and gaurenteed it will be different reading.

I dont know what to do. I really shouldnt have to pay for a new battery when this is under warranty.

Mech says its not the starter gaurenteed! He says dont even waste my money paying him to test it.

 

[Carnoobie]

Originally Posted By: yonyon
Originally Posted By: Carnoobie

So basically you will get different readings with hot battery? AHA I knew it! Guy at Mr Lube said the readings would only be different if car was jumped but not if it was cold or hot. WHICH MAKES NO SENSE?

But see, I cant get these idiots at Mr Lube to replace the battery under warranty because they say it makes no difference whether its hot or cold.


I'm missing something here. Why can't you park the car overnight at Mr Lube?


I do have one 3 min drive from me but I hate these idiots at this location. The biggest morons ever. For all i know i could park it there overnight, then in the morning ask them to test it with the CAR outside their bay and they refuse saying the car has to be in the shop, blah blah blah.

 

[yonyon]

...and that's when you instruct them to push the car into the shop. The battery will not warm up in the time it takes between pushing the car inside and testing the battery. Don't assume the guys you're calling morons will outthink you.

You believe this battery has failed during the warranty period. They are attempting to deny warranty coverage on the grounds that the battery hasn't failed. You have a set of easily repeatable conditions under which you have observed the battery does not appear perform. They have a test. They should apply their test under the conditions that you report show inadequate performance. If they are unwilling to do this the only data available about whether or not the battery functions correctly in those conditions would be your observations (their test means nothing as they haven't tested it) and as such must accept that the battery is faulty.

 

[Carnoobie]

Originally Posted By: yonyon
...and that's when you instruct them to push the car into the shop. The battery will not warm up in the time it takes between pushing the car inside and testing the battery. Don't assume the guys you're calling morons will outthink you.

You believe this battery has failed during the warranty period. They are attempting to deny warranty coverage on the grounds that the battery hasn't failed. You have a set of easily repeatable conditions under which you have observed the battery does not appear perform. They have a test. They should apply their test under the conditions that you report show inadequate performance. If they are unwilling to do this the only data available about whether or not the battery functions correctly in those conditions would be your observations (their test means nothing as they haven't tested it) and as such must accept that the battery is faulty.


But shouldnt they be testing the battery with me cold starting the car and not after i cold started it?

It will take a good 5mins to push the car in and what if they refuse to? Another thing is, i dont even know if i trust them pushing my car in, they could push on the wrong areas and push in my trunk.

The only good thing out of all of this is that my mech can get me a deal on a new battery. Same kind if i wanted for about 35% off. This battery is $130 shelf price. I know expensive. I could have just used a Motomaster one from Costco for $70.

 

[yonyon]

Originally Posted By: Carnoobie


But shouldnt they be testing the battery with me cold starting the car and not after i cold started it?

They should test the battery just before the cold start.
Originally Posted By: Carnoobie


It will take a good 5mins to push the car in and what if they refuse to?

Going from cold weather to a lukewarm shop, the batter will not warm up much in 5 minutes. If they refuse to test outside or push it that is the same as refusing to test it. If they refuse to test the battery, how can they say it's a good battery?
Originally Posted By: Carnoobie

Another thing is, i dont even know if i trust them pushing my car in, they could push on the wrong areas and push in my trunk.

Watch them push it. If they push in your trunk, push in their skulls.

Originally Posted By: Carnoobie - not really

What if I try to push in their skulls and can't do it?

Use hydraulics.

I'm beginning to think you just want to buy a new battery and don't care about the warranty.

 

[Carnoobie]

Originally Posted By: yonyon
Originally Posted By: Carnoobie


But shouldnt they be testing the battery with me cold starting the car and not after i cold started it?

They should test the battery just before the cold start.
Originally Posted By: Carnoobie


It will take a good 5mins to push the car in and what if they refuse to?

Going from cold weather to a lukewarm shop, the batter will not warm up much in 5 minutes. If they refuse to test outside or push it that is the same as refusing to test it. If they refuse to test the battery, how can they say it's a good battery?
Originally Posted By: Carnoobie

Another thing is, i dont even know if i trust them pushing my car in, they could push on the wrong areas and push in my trunk.

Watch them push it. If they push in your trunk, push in their skulls.

Originally Posted By: Carnoobie - not really

What if I try to push in their skulls and can't do it?

Use hydraulics.

I'm beginning to think you just want to buy a new battery and don't care about the warranty.


Im tempted but now when i think of it, cause i have no ride back. I would have to drive there like 12am this morning, park right in front of their bay and sleep there til they open at 8. I could probably do this if i was crazy but its going to be -10 throughout the night! BURRR! Am I willing to do this to save $100? And theres not even any gaurentees theyll replace it. For all i know they could lie or do the test wrong and refuse again. This is Mr. Lube after all!

If that happens i would be [censored] beyond belief. The place is 3min drive from me, I could wake up at like 4am, drive straight there, (not letting the car even get to operating temp cause it is -10) and then sit in the car for 4hrs. That would probably be enough time to get the car 100% cold again but risky.

 

[hemitom]

You know what! Leave the headlights on overnight kill the S.O.B so its stone cold dead and bring that back to them test .

 

[yonyon]

Do you no longer live with your parents? Do they no longer drive?

Stop thinking of ways to spend $100. Think of how to save it.