One black and two red electrical switches

ToddS

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Sep 11, 2017
248
Beneteau 373 Cape Cod
I've owned my Beneteau (373) for a year now, and read several posts in several forums discussing the re-purposing of the black/negative switch and changing how the shutoff switches are wired. While I'm not the original owner of this boat, I'm 99.9% sure my wiring is all original. Also worth mentioning: my electrical system knowledge/skills are fairly basic. Personally, I cannot see any reason to change the way it was originally installed. Here's how I use shutoff switches, and it all seems to work almost* perfectly for me.
  1. When I "open up" the boat to use for a day, weekend or multi-week cruise, I turn on the "house bank" red.
  2. When I "close up" the boat, (basically any time I'm away all day or longer) I turn off the "house bank" red.
  3. When I want to run the engine, I turn on the "starter bank".
  4. When I shut off the engine, I turn off the "starter bank".
This way, all batteries charge while the engine is running. Also, I (or more likely my kids, or the first mate) can accidentally run my house batteries way too low, and that won't impact my ability to start the engine, While not my normal process, this setup also allows me (in a pinch) to start the engine off the house batteries, or run house electrical off the starter battery. Again, that's not ever part of my plan, but nice to have in my back pocket for when things go wrong.

As far as I can tell, the main reason people seem to not like the original setup, is that they leave both banks switched on... run their "house electrical" needs off both batteries (because both are on) and then are surprised that the house electrical drained the starter battery. The original (and my) way seems simple to me: "ON" means that battery is connected to the system. "OFF" means it is not connected to the system.

Is all of the Beneteau rewiring switches fuss really about people finding this setup to be not-intuitive? I guess people just don't like having to turn off the starter when they are finished using the engine eh?

* One improvement I would make, is for boats with multi-battery "banks" as their "house", to have a separate switch for each individual battery, and is on my to-do-list, since I upgraded my house bank from the original single battery, to two parallel batteries (for a total of 3 batteries on board). Additionally, I agree that the black switch has some use only in very specific situations, and I could easily live without it... but having a feature I hardly ever need to use, is hardly a "problem" for me... It's fine as-is as far as I'm concerned.
 
May 17, 2004
3,547
Beneteau Oceanis 37 LE Havre de Grace
I've owned my Beneteau (373) for a year now, and read several posts in several forums discussing the re-purposing of the black/negative switch and changing how the shutoff switches are wired. While I'm not the original owner of this boat, I'm 99.9% sure my wiring is all original. Also worth mentioning: my electrical system knowledge/skills are fairly basic. Personally, I cannot see any reason to change the way it was originally installed. Here's how I use shutoff switches, and it all seems to work almost* perfectly for me.
  1. When I "open up" the boat to use for a day, weekend or multi-week cruise, I turn on the "house bank" red.
  2. When I "close up" the boat, (basically any time I'm away all day or longer) I turn off the "house bank" red.
  3. When I want to run the engine, I turn on the "starter bank".
  4. When I shut off the engine, I turn off the "starter bank".
This way, all batteries charge while the engine is running. Also, I (or more likely my kids, or the first mate) can accidentally run my house batteries way too low, and that won't impact my ability to start the engine, While not my normal process, this setup also allows me (in a pinch) to start the engine off the house batteries, or run house electrical off the starter battery. Again, that's not ever part of my plan, but nice to have in my back pocket for when things go wrong.

As far as I can tell, the main reason people seem to not like the original setup, is that they leave both banks switched on... run their "house electrical" needs off both batteries (because both are on) and then are surprised that the house electrical drained the starter battery. The original (and my) way seems simple to me: "ON" means that battery is connected to the system. "OFF" means it is not connected to the system.

Is all of the Beneteau rewiring switches fuss really about people finding this setup to be not-intuitive? I guess people just don't like having to turn off the starter when they are finished using the engine eh?

* One improvement I would make, is for boats with multi-battery "banks" as their "house", to have a separate switch for each individual battery, and is on my to-do-list, since I upgraded my house bank from the original single battery, to two parallel batteries (for a total of 3 batteries on board). Additionally, I agree that the black switch has some use only in very specific situations, and I could easily live without it... but having a feature I hardly ever need to use, is hardly a "problem" for me... It's fine as-is as far as I'm concerned.
I think you've pretty much got the idea. The full list of potential issues is at https://a4.pbase.com/o10/84/622984/1/166823461.VNTy7g2Q.ZBeneteauBatterySwitchWiring3.jpg, but for the switches themselves you've pretty much summarized what it comes down to. The key is that you know the batteries are combined when both switches are on. The other main downside is that you have to remember to move those switches back and forth all the time, whereas if you have an isolator and emergency combine switch you have the same functionality without ever having to touch a switch.
 
Jun 21, 2004
1,908
Beneteau 343 Slidell, LA
seems simple to me: "ON" means that battery is connected to the system. "OFF" means it is not connected to the system.

Seems simple; however, it isn't. I chartered a new Beneteau 343 about nine years ago. Started sailing and shut down the engine. I shut off the engine battery (#1) and sailed for about 6 hours with the fridge running. When I attempted to start the engine all batteries had discharged to the extent that the engine wouldn't start. There was a relay in the system that remained energized because both switches were not turned off (to de-energize the relay), before turning the house bank back on. Because the relay remained energized, both banks remained combined; therefore, the entire system discharged.

Is all of the Beneteau rewiring switches fuss really about people finding this setup to be not-intuitive? I guess people just don't like having to turn off the starter when they are finished using the engine eh?

As in the example above, there are numerous configurations that Beneteau used over the years. I know that if my engine battery is off, the house bank will not start the engine; that tells me the house and engine banks are not combined unless charging via alternator or battery charger. Todd please let us know if your system is wired like mine.
 
Jan 7, 2014
272
Beneteau 45F5 51551 Port Jefferson
My last boat had a battery isolator installed between the house and starter bank. When the voltage dropped below a certain amount (maybe 13V ) it isolated the two banks when the voltage is higher, say 13.5 like when they are under charge, both banks were connected for charging. Also the main battery switch had "house", "start", "both". Apparently my current boat does not have an isolator. I forgot to shut off start and house and came back to a dead start battery last summer.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
... As far as I can tell, the main reason people seem to not like the original setup, is that they leave both banks switched on... run their "house electrical" needs off both batteries (because both are on) and then are surprised that the house electrical drained the starter battery. The original (and my) way seems simple to me: "ON" means that battery is connected to the system. "OFF" means it is not connected to the system.
Is all of the Beneteau rewiring switches fuss really about people finding this setup to be not-intuitive? I guess people just don't like having to turn off the starter when they are finished using the engine eh? ....
Yeah, sometimes people just have to realize they need to know their boat's systems. My B323 has 3 batteries. It's all in just realizing there are SOME things you must know & do to run a boat.