Overcomplicated Battery Switch Situation?

[BoatNoobie]

Am I making this more difficult than it actually is?

Here's the situation. My plan is to charge my batteries, using a generator that's powering an onboard charger. I also want to protect all the wires and electronics/motors from any potential surges or issues by the generator/charger. Or do I not have to worry about this because the charger should just die from it's fuses or whatever?

Anyways, I was thinking of adding 1 or 2 of shutoff switches, so I don't have to worry about the outboard or anything else on the boat having any sort of parasite drain on the battery. I don't think I'll have to worry about the trolling batteries, so it's just the trolling motor connected to it, and it'll be unplugged at the bow anyways.

[ezfishn]

Would recommend cutoff switches for both cranking and TM batteries so no worries either way in charging or parasitic drain on batteries.

[CatFan]

Batteries are pretty good surge absorbers, and a quality generator is probably less likely to produce a surge than your power provider. I spent most of today with ~$500K worth of electronic equipment in the back of a Gator running off a Honda EU2000i, and most of that stuff has spent hundreds if not thousands of hours running the same way.

[BoatNoobie]

Batteries are pretty good surge absorbers, and a quality generator is probably less likely to produce a surge than your power provider. I spent most of today with ~$500K worth of electronic equipment in the back of a Gator running off a Honda EU2000i, and most of that stuff has spent hundreds if not thousands of hours running the same way.

Well, that's a Honda. I have a Champion, lol. I also forgot to mention, there is a DC charger in the mix too.

I know this is a shitty drawing and probably makes it even more confusing, but it's the gist of it I think.

The only thing I'm not so sure about is the wires for the electronics/accessories. I don't know how it's setup. I don't know if there are multiple wires going to the bilge, or just a single wire from a buss bar. If it is indeed multiple leads, I can connect them all to a single switch with no issues right, then just run a bigger gauge wire out to the battery? Basically turning the switch into a buss bar?

I'm not to worried about draining the trolling batteries, since nothing will be contacted to it, except for the wires from the DC charger and onboard charger.

drawing.JPG

[DQM]

The only thing I'm not so sure about is the wires for the electronics/accessories. I don't know how it's setup. I don't know if there are multiple wires going to the bilge, or just a single wire from a buss bar. If it is indeed multiple leads, I can connect them all to a single switch with no issues right, then just run a bigger gauge wire out to the battery? Basically turning the switch into a buss bar?

You are correct in that you can, and most certainly will, connect multiple positive leads to the output post on the switch.

Looking at your drawing, I have almost the exact same setup.

The only difference is my battery switch is a 1/2/Both/Off switch and I have the starting battery connected to input #1. I jumped the two 12-volt trolling motor batteries for 24 volts at the trolling motor plug. I then added one of the trolling motor batteries to input #2 on the switch.

This way, if for some reason the starting battery is dead I can easily switch from position #1 on the switch to position #2 and the trolling motor battery I have connected. Or of all else fails, switch to BOTH as a last ditch effort.

Have not had to do either (knock on wood) yet :)

[BoatNoobie]

You are correct in that you can, and most certainly will, connect multiple positive leads to the output post on the switch.

Looking at your drawing, I have almost the exact same setup.

The only difference is my battery switch is a 1/2/Both/Off switch and I have the starting battery connected to input #1. I jumped the two 12-volt trolling motor batteries for 24 volts at the trolling motor plug. I then added one of the trolling motor batteries to input #2 on the switch.

This way, if for some reason the starting battery is dead I can easily switch from position #1 on the switch to position #2 and the trolling motor battery I have connected. Or of all else fails, switch to BOTH as a last ditch effort.

Have not had to do either (knock on wood) yet :)

Nice to have redundancy. I carry one of those lithium jump pack in my vehicle that I got recently. I plan on tossing that into the backpack when I head out, just in case.

So looking at all the different styles of switches. There are so many. I'm looking at Blue Sea specifically since they seem to have a good rep.

I was just going to get the version that only cut-off one of the leads, but I started poking around and found the dual version. My thinking is, I can shorten both the charged up positive and negative cables near the battery. The idea is less chance of electrolysis since I have no idea where the leads go or mounted onto. Also, this will reduce the clutter contacted directly to the battery. That's assuming I'm looking at the diagram correctly.

I'm thinking of installing 2 of these. 1 for the trolling motor batteries, and house battery.
https://www.bluesea.com/products/601...y_Switch_-_Red







So going by the diagram, I think that's what one of the usage of this switch.


I am curious about the left side of the diagram with 2 batteries. How does that work? I don't see how they contact the negative side of the battery.

[DQM]

There is no need to connect a negative to the switches. Leave the negative connections where they currently are, either on the batteries or a negative bus bar.

The left picture shows shows a separate house and starting battery wired. When the switch is “On” then both batteries and send current to their respective destinations. When the switch is “Off” then both batteries circuits are broken or off. Bank 1 and Bank 2 on the switch are isolated and just share the on/function of the switch.

The right side side picture just shows how you could wire one battery through the system. But if you only had one battery you could use a single circuit switch.

If if you were going to use two of those switches, and had three batteries (1 for starting and electronics (house) and 2 for trolling motor, you would be best using two single circuit switches, one for starting/house and one for the trolling motor.

The switches are rated for 32 volts maximum, not per circuit, so would not be advisable to use a dual circuit switch for both starting and 24 volt trolling motor.

[Lou r Pitcher]

The switches are rated for 32 volts maximum, not per circuit, so would not be advisable to use a dual circuit switch for both starting and 24 volt trolling motor.

Not correct interpretation of the spec....... The 32 volt spec is for MAXIMUM Voltage being switched. A BSS dual circuit switch has two fully electrically isolated switches that are simply being mechanically linked.

High current switch manufacturers must assume a max voltage limitation in publishing their switches maximum current rating. It is current at a particular voltage that ohms law applies generating the most internal heat that the switch can tolerate.

[BoatNoobie]

There is no need to connect a negative to the switches. Leave the negative connections where they currently are, either on the batteries or a negative bus bar.

The left picture shows shows a separate house and starting battery wired. When the switch is “On” then both batteries and send current to their respective destinations. When the switch is “Off” then both batteries circuits are broken or off. Bank 1 and Bank 2 on the switch are isolated and just share the on/function of the switch.

The right side side picture just shows how you could wire one battery through the system. But if you only had one battery you could use a single circuit switch.

If if you were going to use two of those switches, and had three batteries (1 for starting and electronics (house) and 2 for trolling motor, you would be best using two single circuit switches, one for starting/house and one for the trolling motor.

The switches are rated for 32 volts maximum, not per circuit, so would not be advisable to use a dual circuit switch for both starting and 24 volt trolling motor.

The cost difference between the single and dual switch is minimal in the grand scheme of bust out another thousand lol. Having the negative cut off too with the shorter run just gives peace of mind, to me.


I'm curious about the diagram on the left side. It doesn't complete the loop since nothing is attached to the negative. Nothing on the batteries or coming off the fuse/motor.

[Lou r Pitcher]

I'm curious about the diagram on the left side. It doesn't complete the loop since nothing is attached to the negative. Nothing on the batteries or coming off the fuse/motor.

The necessary negative returns from the load(s) to battery were not included in the simple drawingon the left. Switching the negative at all in disconnecting a batter as in the right drawing is not typically required or practiced. It the positive side of a circuit is OFF and not powered there would be no current draw.

As the shown dual circuit switch is not the 'PLUS' version and has no combine function, the negative returns for the two switched circuits can be common or they can be separate from each other.

[DQM]

Thanks for the insight on the 32 volt maximum.

On a side note, I prefer the e-Series switches to the m-Sseries. The e-Series are larger, but they actually make wiring easier as you can run the 4ga leads out of the bottom or all out of one side. The m-Series I have found you have to run the lead wires through each corresponding side. Just doesn't look as good (or function in my opinion and the e-Series really are not that much larger.