2013-08-16 “8/10s of a volt – The difference between success & failure”

I will get to the headline in a moment but first a little background.  Magnolia was purchased with 2 x 2oo amp/hours of battery storage in her house bank. The amount of storage allowed us to operate the systems aboard Magnolia for about 24 hours without connecting to either shore power or running the Westerbeke 8.5 Kilo-Watt generator for a couple hours while at anchor. I am here to tell you there is nothing more annoying on a sail boat than to hear an engine run whether it’s the auxiliary engine or the generator. The larger battery bank we will not have to run that generator as long!


(Starboard House Bank)


(Port House Bank)

In addition to the House Bank we replaced the start batteries, one for each generator and auxiliary engine. This is where the mystery began. In consultation with my friend Greg and Magnolia’s professional electrician it was decided we would install a Group 27 battery for the auxiliary engine and a Group 24 for the generator. This is where my mystery began. I installed the Group 27 and the Auxiliary Engine operated perfectly. I installed the Group 24 on the generator and it would not even turn over.


(Engine Start Battery)


(Generator Start Battery)

This would be an excellent time to disclose my dirty little secret. I am a lousy mechanic and until we purchased Magnolia the most mechanical thing I ever did was change the oil in my cars. I was such a neophyte my “best” friends labeled me “beer Bi$&h.” I have the coffee cup to prove it!


After the initial start failure of the generator I connected it to the proven Group 27  and the generator started right up. Crazy! Ok, guess the generator requires the increased power available on the Group 27 over the Group 24. Truth be told I nor my ”consultants” believed a Group 27 should be required to start the generator. In spite of the previous I traded for another Group 27. After the installing the Group 27 surprisingly the problem persisted!  What? A quick voltage check indicated a voltage of 12.6 on the “problem” battery and 13.4 on the “good”battery. Are you kidding me??? A call to whom I refer to Mr. Happy (definitely not happy) at Westerbeke he suggested checking voltage at the starter instead of at the battery. It was then that I discovered the ground cable on the generator was ever so slightly loose! CRAP!! Obviously the problem went right away after cleaning and tightening the connection.

Lesson learned, stick with to your instincts. If it appears to not make sense, IT DOES NOT MAKE SENSE!!! In hindsight the above can be seen perfectly clear, the trick is going to be to see clearly during the process! Practice makes perfect, will keep working it!

3 thoughts on “2013-08-16 “8/10s of a volt – The difference between success & failure”

  1. Yeah, corrosion and poor connections are always a problem in this electrical system stuff. Other things I would have looked for that you didn’t mention in this troubleshooting would have been a warm or hot cable. You can use an IR gun or just feel the cables. If one is too hot it means you might have some corrosion leading to the voltage drop.

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