Having read a Maine Sail reply in the past (Beneteau starter batteries are not isolated from the house!) and then the recent query about alternator battery hookups, I would appreciate some input on the following: my Beneteau 343 engine battery is not isolated from the house battery system, indeed, if I only have the engine battery switched on, it will power the house. I wish to isolate the engine battery, so am thinking that I would have only the cable for that battery connected to its switch, and no 12v engine battery wires going to the house circuit (btw, I have three separate switches for the engine battery and the two house batteries, and each has its own 120-to-13v charger circuit). I don't care if the engine alternator is charging the house batteries when underway, as that time is always minimal. What would be the downside to making that change? Thank you.
Isolating starter battery
- Thread starter jmkinsfbay
- Start date
This
https://forums.sailboatowners.com/index.php?threads/1-both-2-off-switches-thoughts-musings.137615/&highlight=beneteau wiring
is a very long thread, one of many I got from a simple search on "Beneteau wiring".
You might wander through all 12 or more pages to find out whether or not there was a specific reply regarding the wiring. We understand the Beneteau wiring differences, and I think Maine Sail and others have commented on it a number of times in the past.
Here's another from that search:
https://forums.sailboatowners.com/index.php?threads/batteries-isolators-charging.179553/&highlight=beneteau wiring
Indeed, Maine Sail answers your question in this ^^^ very thread.
https://forums.sailboatowners.com/index.php?threads/1-both-2-off-switches-thoughts-musings.137615/&highlight=beneteau wiring
is a very long thread, one of many I got from a simple search on "Beneteau wiring".
You might wander through all 12 or more pages to find out whether or not there was a specific reply regarding the wiring. We understand the Beneteau wiring differences, and I think Maine Sail and others have commented on it a number of times in the past.
Here's another from that search:
https://forums.sailboatowners.com/index.php?threads/batteries-isolators-charging.179553/&highlight=beneteau wiring
Indeed, Maine Sail answers your question in this ^^^ very thread.
Many thanks, Stu. Pretty much read through those. The closest to my situation is the Blue - - three On/Off switch panel, but, I didn't really understand the bus bars that ran between the battery switches. If there were no connections between the switches, then that's the conformation I would like to have, and, my alternator would only be charging the starter battery when the engine is running. As far as being able to use one or the other house battery to start the engine, I prefer to just use my jumper cables if that awful event (dead starter battery) were to happen. So, given that, is there a bad side to what I want to do?This
https://forums.sailboatowners.com/index.php?threads/1-both-2-off-switches-thoughts-musings.137615/&highlight=beneteau wiring
is a very long thread, one of many I got from a simple search on "Beneteau wiring".
You might wander through all 12 or more pages to find out whether or not there was a specific reply regarding the wiring. We understand the Beneteau wiring differences, and I think Maine Sail and others have commented on it a number of times in the past.
Here's another from that search:
https://forums.sailboatowners.com/index.php?threads/batteries-isolators-charging.179553/&highlight=beneteau wiring
Indeed, Maine Sail answers your question in this ^^^ very thread.
JM if your switches are like my B323 (on the front, bottom of the 1/4 berth)... I changed the ground switch to red when I added a third battery. My "12v buss" is a strap across the three outputs of the switches. Everything that makes or uses 12v is wired to that buss can be turned on or off, mainly to rotate the batteries as to their charging or discharging. It's a matter of routine, and not a concern that wears down my brain.
Thanks, Ron - - - - - . For further thought, then, do you have 3 chargers for your 3 batteries? If not, there will be cross-charging, presuming your charger(s) is (are) wired to the battery side of the switches, and a single charger will not be able to tell which battery (ies) need to have what charge. Likewise, with the engine running, if you have bus bars across the outputs, and you have an engine battery and a house battery switched on, the alternator will be charging the two (or three!) at the same voltage, which I believe is not a major problem for short engine-running times. Maine Sail suggested that a negative switch was pretty much useless, so I'm impressed that you used it for your third battery; that will probably be the resolution for my being unable to find another of those battery switches that come on Beneteaus. Can I presume, then, that you just banked all of your batteries' negatives to a common bus bar, somewhere in that compartment. And, did you then bring all house wiring negatives to that bus bar? And finally, I find myself overwhelmed by all of the controls and boxes that are wired into the system under there.