After finding that our batteries had prematurely died we started the process of trying to determine the cause. The post below gives some background on the process so far.
http://[URL="http://forums.hunter.sailboatowners.com/showthread.php?p=946947&highlight=electrical"]
After making the battery compartment flooring repairs that I found were needed I then did the rewiring previously discussed to bring our installation more in line with traditional recommendations for wiring of marine 12V DC systems. Thanks to all who helped previously with their feedback. In addition to doing this to eliminate possible unknown issues this hopefully would give me a good starting point to diagnosis for ground faults/stray voltage etc..
When I completed the wiring (see attached diagram of completed work) I began to test for ground leaks. First I disconnected the shore power cable from the boat. Secondly I disconnected all electrical equipment bypassing the DC panel that was wired to the batteries directly (stereo always hot/on lead, auto bilge pump, battery monitor, etc... I Then removed the positive battery clamp and placed a voltmeter between the post and the clamp for the house bank and then later for the starting bank. The result in both cases was voltage ranging up to 5 volts.
I have tried testing for voltage with the battery switch in the Off position as well as in the On position for each bank to try to determine which side of the switch the leak(s) are on with limited success. There is always voltage on the line.
After many attempts to isolate the leaks by leaving the battery switch in the on position and disconnecting individual pieces of equipment at the panel with no results I noticed something very odd. I had physically disconnected the house bank from the switch and boat ground and only left the starting battery connected to the switch. I had the volt meter still running from the positive post of the starting battery to the clamp that connects the starting battery to the switch. Even with the switch end of the cable disconnected from the switch the meter shows appx. 2 volts still. I have tried another meter to be certain but get the same results.
Additionally I did notice that as I was tightening the positive clamp back on to the battery I was also holding on the the stainless steel wheel and received a mild shock.
I have read about stray current coming from outside the boat but could that account for so much Voltage? Similarly as it related to Galvanic current, could it generate this much voltage? If anyone has any suggestions I would appreciate it.
http://[URL="http://forums.hunter.sailboatowners.com/showthread.php?p=946947&highlight=electrical"]
After making the battery compartment flooring repairs that I found were needed I then did the rewiring previously discussed to bring our installation more in line with traditional recommendations for wiring of marine 12V DC systems. Thanks to all who helped previously with their feedback. In addition to doing this to eliminate possible unknown issues this hopefully would give me a good starting point to diagnosis for ground faults/stray voltage etc..
When I completed the wiring (see attached diagram of completed work) I began to test for ground leaks. First I disconnected the shore power cable from the boat. Secondly I disconnected all electrical equipment bypassing the DC panel that was wired to the batteries directly (stereo always hot/on lead, auto bilge pump, battery monitor, etc... I Then removed the positive battery clamp and placed a voltmeter between the post and the clamp for the house bank and then later for the starting bank. The result in both cases was voltage ranging up to 5 volts.
I have tried testing for voltage with the battery switch in the Off position as well as in the On position for each bank to try to determine which side of the switch the leak(s) are on with limited success. There is always voltage on the line.
After many attempts to isolate the leaks by leaving the battery switch in the on position and disconnecting individual pieces of equipment at the panel with no results I noticed something very odd. I had physically disconnected the house bank from the switch and boat ground and only left the starting battery connected to the switch. I had the volt meter still running from the positive post of the starting battery to the clamp that connects the starting battery to the switch. Even with the switch end of the cable disconnected from the switch the meter shows appx. 2 volts still. I have tried another meter to be certain but get the same results.
Additionally I did notice that as I was tightening the positive clamp back on to the battery I was also holding on the the stainless steel wheel and received a mild shock.
I have read about stray current coming from outside the boat but could that account for so much Voltage? Similarly as it related to Galvanic current, could it generate this much voltage? If anyone has any suggestions I would appreciate it.
