Battery on/off switch

[bruceb58]

Re: Battery on/off switch

Rule #1. ALWAYS follow the manufacturers recommendations on installing any accessory, regardless of what you may read elsewhere. I got in a huge argument with a guy who claimed to be an electrical engineer over this.

Now, when I installed my battery cutoff switch on my travel trailer, I put it in the negative (-) side. Current leaves the battery on that side and returns on the positive (+) side. The closer you can get the switch to the (-) side, the fewer chances you'll have of a short or other 'leaking' voltage.

When in doubt, always referr to rule #1!

First of all, the definition of direction of current and the direction of electrons are two different things and it doesn't matter whether you interrupt the negative or positive side. Since the convention with negative ground systems is to put the switch on the positive side, that is where you should put it. Every other switch on the boat switches on the positive side. Why all of a sudden is it best to put it on the negative side? And yes...I am a EE.

If your switch is 1 foot away from the battery or 3 ft away, you won't have "leaking" voltage.

 

[capndan]

Re: Battery on/off switch

Thanks again, Silvertip...I should have been able to figure that out from the diagram.

 

[Mr Crabbs]

Re: Battery on/off switch

Bruce, do we know for certain that no insulation will be cut or rubbed off between a cutoff switch and the (-) terminal? Uncertainty is why you put it as close as you can. This also is not just another on/off switch, it's there to isolate the battery from potential discharge.

I'm not going to get in another argument of the older conventional flow theory vs electron flow theory.

When in doubt, see rule #1!

 

[bruceb58]

Re: Battery on/off switch

I'm not going to get in another argument of the older conventional flow theory vs electron flow theory.

Good..because that aspect doesn't even matter here.

When in doubt, see rule #1!

I agree with rule number one and there is an ABYC rule about it as well.

ABYC 11.7.1.2.1. A battery switch shall be installed in the positive conductor(s) from each battery or battery bank with a CCA rating greater than 800 Amperes.

http://www.blueheronmarine.com/files/BlueSea_Battery_Switch_Comparison.pdf
http://bluesea.com/files/resources/instructions/9003e_web_version.pdf