AGM Battery Capacity Tester Tool (A Link)
These things used to be fabulously expensive. https://www.banggood.com/FDY10-H-Battery-Capacity-Tester-60V-10A-Discharge-Test-Instrument-p-1052906.html?rmmds=search
Forum Discussion
Lifeline decided not to answer my question regarding their choice of a 25 ampere discharge value. I look at it this way, it is similar to establishing ampere hour capacity on a flooded battery using the RC reserve capacity discharge value rather than the 20 hour ampere rate.
Peukert differential enters the picture. Why does Concorde prefer the RC rate of discharge? Read Mr. Wizard's answer.
I cannot envision a scenario where I discharge any of my Lifelines using a 25 amp value. The 10-amp figure is more realistic. And will yield a product more in line with reality. The 25 ampere capacity test is light years better than guesswork but coupled with an insane price to do the test without personal supervision means a prohibitive price tag for the testing apparatus.
NOTE ABOUT YOUR GC220 batteries
BCI load test is to apply 50% of CCA rate for a period of 15-seconds to 6 cells in series. If voltage drops below 9.6 volts during test, recharge and retest.
Personally I have never seen a GC220 exhibit higher than a suggested 450 CCA rating*. Carbon pile load testers need to be designed for the voltage of the accumulator. Load test three cells and the carbon disc compressor can be squeezed down as tight as it will go and amperage discharge will not even get close to a useful value. Six cell series testing is a must. It involves use a second battery but by monitoring one of the two batteries for voltage (4.8 under test load) it is possible to isolate which battery if any might be an offender.
I constructed a dedicated 3-cell load tester using 10 gauge nichrome wire, because of the number of batteries I had to test. In the gen shed, I have a 675 ampere 2 volt discharge load made from 8 gauge nichrome wire. The wire itself cost almost a hundred dollars 35 years ago.
Anyway, the 15 second BCI load test is inadequate for thick plate batteries. I increase loading time to between 20-30 seconds. The voltage must not suddenly slump.
The HF carbon pile tester desperately needs a pusher fan to cool the carbon discs. A high CFM fan will draw perhaps 2 amperes - inconsequential bleed and therefore not influential to the test product result.
*600 ampere load on 6 cells in series would be appropriate for a 1200 CCA battery. Many 29 plate 8-D batteries are in this range, but not the GC220
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Load tester and bad connections. Years ago a friend by the name of "Dean" had a live aboard docked in the Noyo harbor. Dean was a PhD mathematician. He called me one day to diagnose an "irresolvable" problem. I diagnosed it as a battery paralleling connector problem. "impossible" he retorted, "I examined every connection myself" Out came the calculator, and Ohms law started being scribbled on notebook paper. "Your diagnosis is wrong" he declared.
"Follow me" I ordered. I had an Auto Meter 800 amp carbon pile tester.
I connected the tester to one battery and cranked the load to the sum of both batteries 50% CCA.
"Fire!" he yelled as a wisp of smoke rolled out of the engine room. There was no fire. just the angry bad connection. Theory is one thing, a REACTIVE resistance another. E=MC2 theory does not correlate to reality when troubleshooting.
Peukert differential enters the picture. Why does Concorde prefer the RC rate of discharge? Read Mr. Wizard's answer.
I cannot envision a scenario where I discharge any of my Lifelines using a 25 amp value. The 10-amp figure is more realistic. And will yield a product more in line with reality. The 25 ampere capacity test is light years better than guesswork but coupled with an insane price to do the test without personal supervision means a prohibitive price tag for the testing apparatus.
NOTE ABOUT YOUR GC220 batteries
BCI load test is to apply 50% of CCA rate for a period of 15-seconds to 6 cells in series. If voltage drops below 9.6 volts during test, recharge and retest.
Personally I have never seen a GC220 exhibit higher than a suggested 450 CCA rating*. Carbon pile load testers need to be designed for the voltage of the accumulator. Load test three cells and the carbon disc compressor can be squeezed down as tight as it will go and amperage discharge will not even get close to a useful value. Six cell series testing is a must. It involves use a second battery but by monitoring one of the two batteries for voltage (4.8 under test load) it is possible to isolate which battery if any might be an offender.
I constructed a dedicated 3-cell load tester using 10 gauge nichrome wire, because of the number of batteries I had to test. In the gen shed, I have a 675 ampere 2 volt discharge load made from 8 gauge nichrome wire. The wire itself cost almost a hundred dollars 35 years ago.
Anyway, the 15 second BCI load test is inadequate for thick plate batteries. I increase loading time to between 20-30 seconds. The voltage must not suddenly slump.
The HF carbon pile tester desperately needs a pusher fan to cool the carbon discs. A high CFM fan will draw perhaps 2 amperes - inconsequential bleed and therefore not influential to the test product result.
*600 ampere load on 6 cells in series would be appropriate for a 1200 CCA battery. Many 29 plate 8-D batteries are in this range, but not the GC220
---------------------------------------------------------------------------------------------------------------------------
Load tester and bad connections. Years ago a friend by the name of "Dean" had a live aboard docked in the Noyo harbor. Dean was a PhD mathematician. He called me one day to diagnose an "irresolvable" problem. I diagnosed it as a battery paralleling connector problem. "impossible" he retorted, "I examined every connection myself" Out came the calculator, and Ohms law started being scribbled on notebook paper. "Your diagnosis is wrong" he declared.
"Follow me" I ordered. I had an Auto Meter 800 amp carbon pile tester.
I connected the tester to one battery and cranked the load to the sum of both batteries 50% CCA.
"Fire!" he yelled as a wisp of smoke rolled out of the engine room. There was no fire. just the angry bad connection. Theory is one thing, a REACTIVE resistance another. E=MC2 theory does not correlate to reality when troubleshooting.
