Battery Testing Procedure
SInce I have soooooooooo much time on my hands here at the shop,Ive been watching various educational videos.
In this video a battery testing procedure is being discussed that I have never heard of before, as well as debunking the continued use of carbon pile testing. Enjoy.
(The battery testing in question begins around the 26.00 mark)
The video is 100% correct. Twice in the past year I have told customers that their new "value" battery needs to be replaced along with my supplied alternator. These batteries passed the CCA and conductance tests but failed the amperage recharge test. I told them the alternator would not have a guarantee if it did not leave the shop charging less than 10 amps at idle.
I have tested thousands of batteries and many thousands of alt/gen.. .Doing so I have never seen a battery drawing 40/50 amps,,Only heard of it ,Most I ever see is 5/10 amps.For a good battery and charging system the charge current is in the milli amps (200/300) after about 15/20 minutes with engine running. If one did have a battery drawing that much current then the mechanic did…
Glad to see you are still in the game, George! I thought you were retiring!
George- Or anyone else, will the amperage draw of a battery increase somewhat linear as the battery starts to age? If it does, do you have and explanation or opinion as to why?
Amperage will decrease linear.The plates get warn out...electrolyte gets contaminated....This causes the chemical reaction time to slow down also.... Temperature also is a factor......Also when the external load equals the internal resistance of the battery we will have max current available. A example of chemical reaction time was in one of Louis post where he had a vehicle that would not…
George- So the amps decrease with age? So if a battery is pulling over 10 amps,its not because it is old,it is because there is a defect of some sort internally?(assuming all other factors are normal) Ive amped clamped about 15 cars so far since I posted this and none were higher than 4-6 amps. The batteries were in various stages of decay(according to my conductance tester), but now I wonder…
Rudy........ What was the final current after the battery finally got fully recharged from cranking the vehicle ? It should eventually go to milli amps after 10/15 minutes......What would be the effects if this 4-6 amps was constant ? Seems to me if you keep charging a battery with 4-6 amps after it has been full charged you gonna have short life due to electrolyte evaporation.
That video is spot on. Over the years, I have seen a few batteries that would draw in excess of 30 amps, which each of those was in because the generators didn't last very long. I have a test all set up on my Pico that I use for testing batteries and generators & starters.
I took this class many years ago and vince is right .. And I have proven it
Thanks for the link, Rudy I've taken a few of Vince's classes many years ago, the video was a good refresher course...
The test is very reliable Rudy. I use it all the time and have specs on the buses I work on. If your curious about specs for certain batteries a lot of the time the manufacturer will supply specs for the maximum amount of current it is allowed to draw, even though the 10 amp rule Vince talks about for cars works very well.
What sort of current draw are you seeing on 24v systems Michael? And on what Ah batteries? Carl
I had kind of forgotten about this test. I had used on occasion in the past, I still like the carbon pile tester. I had a volvo xc90 yesterday that needed a battery. I used the test outlined and got this waveform. Drawing 38 amps at idle. The battery was bad, the battery also failed with carbon pile tester. Plus you see how low the voltage dropped during cranking. I would have gotten an after…