Battery Load Test ?

[Cressida]

I have a 6 to 7 year old battery that appears to be working normal. In the past I've just checked them with my voltage meter and waited until there were obvious signs the battery was failing to replace them.

However for peace of mind, I'm thinking about having a load test done on the battery since it might be good to know of it's condition (?) and wondered does this test do any permanent harm? Also I think it's best to remove the battery from the vehicle and take it to AutoZone or Advanced, etc. to have them do the load test - - is that correct or can it safely be tested while the battery is still installed in the car?

It is a side post battery and pretty hard to get to the terminals if that makes any difference. Do I need to know the load (e.g CCA) that they should use and the voltage number it should fall down to during the test?

 

[Dave Sherman]

I haven't had to take the battery out for a load test. They put the CCA numbers printed on the battery into their tester and it tests it appropriately. I don't have tremendous faith in their tester's assessment of the rest of the electrical system. One of them reported that the battery, starter and alternator were all faulty on one of my Hondas. From the current measurement it reported on the starter, it passed Honda specifications so I'm not sure how it figured it was bad. I got home, turned on everything electrical I possibly could turn on, and it still met Honda's voltage requirements. I saw some article later that since Honda (at the time) used an alternator that switched between high output and low output instead of being linear like conventional one, it could trigger false failures on those tester boxes.

 

[JMJNet]

If there is Harbor Freight nearby, I will buy my own old school load tester for around $20 (there are 25% coupon for Easter which makes it even cheaper).

It is very easy to test, assuming the battery is charged, you hook it up and press a button.
You should see how it performs because the needle will move lower or not.
If it moves lower to the red section, then the battery is bad.
When the tester apply the load, the voltage should stay within a range.

 

[Trav]

I rather use this one, over the years using a load tester I have had many batteries fail within a short time after that tested good. Coincidence, battery on its last legs? No idea.

https://www.amazon.com/dp/B00IZFNJ6Y/ref=psdc_15707371_t1_B0015PI7A4

 

[JeffKeryk]

A battery that old is suspect in my book.

 

[dogememe]

Any auto parts store can test it in the vehicle assuming the battery is fairly well charged. I work at a national auto parts chain and we just select the right type of battery (regular, AGM, etc), read the CCA off the sticker, put it in the tester, and it says GOOD, GOOD, LAST QUARTER OF LIFE, or BAD - it doesn't report actual CCA. Apparently ours used to, but they updated the software to just say good or bad - I suspect that was because customers had batteries at the end of their warranty tested and demanded new ones if the shown CCA was 1 less than the one on the sticker (or something like that)... The test is safe for the battery, it's really no different than sitting there cranking the starter for 5 seconds... That said, a 6+ year old battery is probably towards the end of its lifespan, so perhaps it'll die in a week, but not because of the test.

 

[benjy]

many auto parts stores like autozone will load test free.

 

[pandus13]

I replaced my Hyundai Elantra stock batteries at 4 years (both times failures),
My Toyota Yaris at 9 years (preventative),
My Mazda5 at 5 years (preventative, tested good, just too many short trips, but was a former Texas car and heat kills batteries and this was the mom-mobile)

Back to topic:
The Mazda5 got discharged after 2 days of sitting in high heat (and a lot of short trips).
Got it jumped, then away I went to AAP.
They run the load test: Battery good, just charge and be on your merry way. Went home, bought a charger, dismount battery, charge 2 times over 48 hours, good for a year. I replaced just based on former Texas car and DD/mom-mobile

 

[Donald]

The load tester at an auto parts store typically do temp compensation. The testers you can buy for under several hundred dollars don't do temp compensation.

 

[willbur]

Originally Posted by Trav
I rather use this one, over the years using a load tester I have had many batteries fail within a short time after that tested good. Coincidence, battery on its last legs? No idea.

https://www.amazon.com/dp/B00IZFNJ6Y/ref=psdc_15707371_t1_B0015PI7A4


Trav-
should one apply a temperature correction for the CCA displayed on this tester? The better testers i.e. Midtronics do but at this price this tester probably does not?

I would like to buy this item or is it even necessary if I check specific gravity and use a cheap 100 amp load tester?

 

[Trav]

It is not temperature compensated but I use it between 60-90f and it doesn't seem to make much difference. Fully charge the battery and test it, it seems to be pretty accurate when I tested a brand new battery.
You can also check the charging system with it, its not an expensive garage tool but its more than good enough.
The midtronics is a better unit but not that much better that I would spring many times the price for it. I like the fact that it is non destructive testing.

 

[DoubleWasp]

Harbor Freight Rat Roaster is a winner.

For fun, put the positive end on the starter stud to see how your wiring losses are. Might be surprised!