Saturday, May 05, 2012


After charging up the battery bank and then disconnecting the batteries I let them rest over night. I came back on board the next day and measured each battery's voltage and did two tests on each battery  using the Centech Battery Analyzer  and a 100 Amp Battery Load Tester.

Here's a quick video showing how to use the Centech Analyzer:

Here is the data I got from the Centech battery analyzer testing

                                      VOLTS   mOHM  CCA     BAT CAPACITY
BATTERY 1                   12.94      2.39      1235          100%
BATTERY 2                   12.45      2.33      1265          100%
BATTERY 3                   12.92      2.35      1241          100%
BATTERY 4 (suspect)   12.92      2.48      1179          100%

All batteries have passed the test from the analyzer. Though battery 4 (the lowest battery in the string) is certainly has a slightly diminished CCA (Cold Cranking Amps) reading compared to some of the others. But, it still passed the tests. The parasitic load from the Paktrakr that was on this battery for four years seems to have weakened it a little. It also has a slightly higher milliohm resistance reading compared to the other batteries not much more though. This might be due to some sulfation internal to the battery because of the parasitic load.

I followed the Centech battery analyzer test with the  100 Amp Battery Load Tester. All batteries passed that load test too:

Obviously, I will be keeping an eye on battery four which when I started this investigation would not even complete a charge on two separate battery chargers. After those results some might have just thrown the battery away and replaced it. But, as you can see it did manage to redeem it's self over time once the parasitic drain was removed. Why all of a sudden did I have this problem after four years? The only thing different this year is that I did not have my 48 volt Air X wind turbine also providing additional charging over the winter layup. This made the solar panels the only charging source and it may have not been enough considering the constant parascitic load on the fourth battery. I also added an additional device to monitor the charging of the battery bank. This additional load may have been enough to add additional sulfation to the suspect battery. So the lesson learned for this electric sailor is to keep parasitic loads off any one battery in the string. Another good thing from this investigation is I now have data to see how each individual battery the 48 volt propulsion bank ages from here on.

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