Battery Tester Temperature Compensation

[willbur]

Greetings All-
Bought a HF digital battery tester that reports battery health, CCA, etc. I know that battery output/capacity is highly dependent on ambient temp. For example ; at 80F its 100% and falls off to 40% at 0F. So...do the test results (AH, CCA, CA, health %, etc.) require temperature correction to the 80F standard? I tested mine yesterday; it reported battery health as 92%, AH as 80 (70 spec) at 70F. If it were instead 40F, would the results be significantly different and maybe indicate the battery was defective/weak when it was actually in great condition?

JHZR2 this is right up your alley...

 

[MSCH]

from what I understand those electronic testers measure the internal resistance of the battery and do their calculation based on that.
one thing for sure is if a 40 degree battery passes the test, it should pass at 80F... as it becomes more efficient at 80 than it does when cold.

 

[willbur]

from what I understand those electronic testers measure the internal resistance of the battery and do their calculation based on that.
one thing for sure is if a 40 degree battery passes the test, it should pass at 80F... as it becomes more efficient at 80 than it does when cold.

good point

 

[Petr]

If it were instead 40F, would the results be significantly different and maybe indicate the battery was defective/weak when it was actually in great condition?

Did you read the manual? The internal resistance is highly temperature-dependent. More smart battery testers might have some tricks how to estimate the resistance better regardless of the battery temperature (e.g. use a ratio of high frequency currents vs. DC current, etc.). If the temperature is not mentioned in the user guide at all you can bet the tester always assumes room temperature environment.

 

[willbur]

Did you read the manual? The internal resistance is highly temperature-dependent. More smart battery testers might have some tricks how to estimate the resistance better regardless of the battery temperature (e.g. use a ratio of high frequency currents vs. DC current, etc.). If the temperature is not mentioned in the user guide at all you can bet the tester always assumes room temperature environment.

Sure, I read the manual and called the company- no help. The "more smart" testers (e.g. Midtronics) do measure ambient temp and compensate for it. My question was is the lack of temp compensation significant?

 

[Petr]

It starts to be significant if you perform the test at battery temperatures below approximately 10C (50 F). At lower battery temperatures you will get lower CCA numbers from the tester. At 0F you may see the internal resistance almost double the value you would get at 80F.

 

[MSCH]

Sure, I read the manual and called the company- no help. The "more smart" testers (e.g. Midtronics) do measure ambient temp and compensate for it. My question was is the lack of temp compensation significant?

look at it this way, since a battery is less effective at 40F than it is at 80F,
since it passed the test at 40F it stands to reason it will pass the test at 80F easier.

 

[willbur]

It starts to be significant if you perform the test at battery temperatures below approximately 10C (50 F). At lower battery temperatures you will get lower CCA numbers from the tester. At 0F you may see the internal resistance almost double the value you would get at 80F.

Thank you. Have a source for this info?

 

[MSCH]

Thank you. Have a source for this info?

What Petr was saying is true...
*80F is generally the auto standard test value for Batteries or compensated to that temp..
CCA is given at 0F
CA is at 32F.
old days we used a carbon pile and ammeter to load test batteries.. all compensation was to 80 and most testing needs to be performed on a relatively warm battery.

in the same manner that the W rating on multi vis oils is at 0F.. but the other oil vis number is I believe 212.
I'm sure there is a source for you, but its just as easy for you to accept others words on this one
instead of thinking it is something different..

most 12v auto batt ratings are from the 80F standpoint...

 

[Petr]

For example have a look at this figure:

https://www.researchgate.net/figure/Dependence-of-internal-resistance-versus-temperature-for-lithium-based-batteries-LiFePO_fig15_316171277

While the temperature dependence of internal resistance is not linear in general, in the range between approx 0C to approx 40C it is almost linear. Therefore it is not a big deal if you perform the test at +10C (50F) or 30C (86F) - the error will be relatively small (e.g less than 20%).
However, at some colder temperatures, the resistance starts to increase really rapidly.

 

[willbur]

What Petr was saying is true...
*80F is generally the auto standard test value for Batteries or compensated to that temp..
CCA is given at 0F
CA is at 32F.
old days we used a carbon pile and ammeter to load test batteries.. all compensation was to 80 and most testing needs to be performed on a relatively warm battery.

in the same manner that the W rating on multi vis oils is at 0F.. but the other oil vis number is I believe 212.
I'm sure there is a source for you, but its just as easy for you to accept others words on this one
instead of thinking it is something different..

most 12v auto batt ratings are from the 80F standpoint...

Not thinking anything differant- just want to know. Appears you like to state the obvious that everyone knows already

 

[MSCH]

Not thinking anything differant- just want to know. Appears you like to state the obvious that everyone knows already

sorry but this forum is more oil specific than that sort of thing.
you probably would be better off going to a battery tutorial elsewhere on the internet.
Somewhere back there in all my training they probably told me why they use 80F as the baseline
but I don't remember anymore.

try here for answers

Battery Basics - Guide to Batteries | BatteryStuff

Learn how a lead acid battery works, more about battery maintenance and the difference between flooded, AGM and gel batteries. Read the tutorial today.

www.batterystuff.com

 

[willbur]

sorry but this forum is more oil specific than that sort of thing.
you probably would be better off going to a battery tutorial elsewhere on the internet.
Somewhere back there in all my training they probably told me why they use 80F as the baseline
but I don't remember anymore.

try here for answers

Battery Basics - Guide to Batteries | BatteryStuff

Learn how a lead acid battery works, more about battery maintenance and the difference between flooded, AGM and gel batteries. Read the tutorial today.

www.batterystuff.com

Thank you. True about that oil thing.

 

[MSCH]

Thank you. True about that oil thing.

sometimes you learn the standard and don't really need to know why.
But it seems the whole focus of this forum revolves around why and why not
even if it doesn't really matter.

 

[bbhero]

Not thinking anything differant- just want to know. Appears you like to state the obvious that everyone knows already

Cadex has a Battery University page to go to….

I’d recommend that one. Extremely informative and it gives a lot of answers to a number of different aspects about batteries.

 

[spasm3]

How do these electronic battery analyzers compare with a carbon pile tester?

 

[Petr]

Carbon Pile Load Tester Vs. Digital Load Tester (2023)

In the world of battery testing and maintenance, there are two primary types of testers that reign supreme: carbon pile load testers and digital load testers. As with any tool or piece of equipment, each type comes with its own set of benefits and drawbacks. In this comprehensive review, we’ll...

claytonnotes.com

 

[f355spider]

How do these electronic battery analyzers compare with a carbon pile tester?

I believe the carbon pile tester is still considered the gold standard. But I ditched mine years ago for a digital one. The convenience factor won out. And after some use, I have full confidence in the readings.

 

[Donald]

The HF carbon pile load testers are roughly the same price as the fancy ones that read CCA. And mine is analog with a few different scales to deal with temperature.

Only problem is the battery must be fully charged for a carbon pile load tester to give an accurate reading.