Master Cut Off Switch?

[Woodbinekeith]

Is a master cut off switch a good (necessary) thing to have. If so, where is the best place to locate it. I'm guessing that it would wire into the primary +ve wire somewhere close to the battery. All my electrics go through individual circuit breakers so perhaps a master switch might be overkill and just another connection that can foul up.

With a switch, it should be ok to leave the motor battery cables attached when not in use as well as the primary cables for the electrics - or will their somehow still be leakage that will discharge the battery?

 

[5150abf]

Re: Master Cut Off Switch?

With a master switch you are sure the battery will have the same charge as when you left it, I think it is a good idea and have one on my boat.

Put it where ever it fits on the boat, closer to the battery means les wiring but it can really go anywhere.

I have 2 batteries for the boat adn a starter, on is up fron and one is in the back so I put the switch in the middle, only my batts for the boat are on the switch, never had a problem with the starter leaking down..

 

[Bayliner175xt]

Re: Master Cut Off Switch?

Hi, we have just put a master switch into our bayliner,
We bought a 300mm battery cable and a switch,
Set it all up and then made a little Marine ply plate that we bolted to a panel under the back seat, Once we where happy with the setup I sealed the little panel, then bolted it all up and clamped the cables away, nice neat job, I think it is a must for safety as well as knowing your battery will be close to full charge when you want it.

 

[sasto]

Re: Master Cut Off Switch?

I also like a battery cutt-off switch for emergency situations. I would think your electrical components are protected by a fuse but it's almost impossible to protect every piece of wire on the boat. DC voltage can cause a deadly fire. My electrical wire feed was not protected untill it joined the fuse box under the console. A short caused the console to start smoking. Shut down batteries, saved boat from possible fire. Also handy when servicing.

 

[rwidman]

Re: Master Cut Off Switch?

Many, if not most, boats are wired from the factory with a battery switch, either for one or two batteries. It's a good idea. The circuit for the bilge pump(s) should not be connected through the switch it shouls receive power at all times.

For anyone thinking of adding one, It would be a good idea to pick up one or two of the books on boat wiring and study them to find out what kind of switch, where to put it, and how to wire it.

 

[Silvertip]

Re: Master Cut Off Switch?

A MASTER switch can mean two different things depending on where it is installed and what it controls. If you are calling a "battery disconnect switch" a master switch then it is best to locate that right at the battery to eliminate two long runs of heavy gauge wire. Since you install that switch at the battery, the engine would be disconnected as well although it could be set up so the engine connection remains directly at the battery. However, if you want to disconnect things, why not disconnect them all.

Many boats have a MASTER switch on the console. This switch is very different from a battery disconnect in that it disconnects the +12 volt feed to the Console. If you are one that tends to forget to turn things off, then adding this switch is suggested. This switch has nothing to do with disabling the engine electrics or anything related to it.

 

[Fed]

Re: Master Cut Off Switch?

I think it's an overkill unless you are going to run dual batteries and then you would want a 1+2+both switch.

 

[seabob4]

Re: Master Cut Off Switch?

One thing to keep in mind is a "Battery Switch" can deter thieves, as this is something we all have to be aware of. Hidden, yet accessable to the owner, especially boats kept on lifts, can cause a thief to look for an easier target.

That being said, the only items that need to wired to the batt 1 or batt 2 post on the switch is the bilge float constant hot and the stereo memory, to keep the time/pre-sets. The rest of the boat gets wired to the common terminal, and when you shut off the switch, nothing can draw power...

 

[cr2k]

Re: Master Cut Off Switch?

Good idea, I think.
Eliminates any erroneous drains on the battery when not needed. Just keep in mind if the engine is running when you shout it off all those amps the alternator is pumping out WILL go somewhere and that could be expensive. Just use it as an alternative to disconnecting the battery.

The Perko OFF-1-ALL-2 switches are make before break and CAN be switched between batteries with the engine running, BUT NOT to off.