Wiring question with battery charger and selector switch..

[mfreeman451]

I have 2 batteries in my boat, one at the bow and stern. I have a 2 bank minn-kota 220 charger mounted near the battery at the bow, I need to run extensions for the charger to reach the stern battery, this stuff isn't cheap and I've already invested 60$ into the 8ga wiring. My problem is I also have a battery selector switch (https://greatlakesskipper.com/produ...m-boat-3-position-batter-selector-switch.html) that I want to mount near the stern that will allow me to switch which battery the outboard is using to start off of, in case I ever kill the starting battery with my electronics. Can I use the same 8ga cable that I have to run for the charger or do I have to run another set, or do I have to use 2 switches?

I'm kind of confused by the whole thing, any help would be appreciated..

 

[mfreeman451]

Maybe I need one of these?

https://www.amazon.com/Blue-Sea-Systems-Solenoid-120A/dp/B000OTIPDQ

 

[FuzzyGrub]

The charger wires go direct to the battery. The leads from the charger will usually reach, but you might have to move its location to something toward the middle of the two batteries. If going to add extensions, go up to one size larger, and splice in so fuse is near battery.

Battery switches, usually use larger wire than 8ga and have batteries closer together. 4ga might not be large enough. I have not run a switch at those distances.

From another forum:

Here is a simple wiring diagram for a dual battery switch. All loads get connected to the COM terminal. Note that all cables in this diagram must be the same gauge or larger than the regular battery cables. Wires feeding the loads need only be sized appropriately for that load.

 

[RivRunR]

I know you've already got the battery selector switch, but if the only reason for the selector is backup for your cranker, it might be a lot easier to just carry a set of marine jumper cables?

 

[mfreeman451]

got those too.. I might be returning the selector switch after all..not sure yet