Dual battery switch

[Ryan Pittman]

Im having a hard time finding directions for hooking up dual batteries and a switch with the dual engines....seems pretty easy to do with a single engine...ive read with the dual engines you need two switches which i dont want....is there a way to hook up dual batteries with the dual engines on a single switch?

 

[Andy S]

Yes, on whatever diagram you are looking at for single engine with dual batteries, just connect both engines to switch post that the diagram shows for the single engine. This is no different than connecting both engines to the same battery.

 

[Ryan Pittman]

Yes, on whatever diagram you are looking at for single engine with dual batteries, just connect both engines to switch post that the diagram shows for the single engine. This is no different than connecting both engines to the same battery.

I guess my concern with doing that was the two engines going through the switch instead of one and causing a fire or something...

 

[RightStuff]

Here's a link to my install from a few years ago, I think the picture of the wiring to the switch will show how the wires from the engines go thru the switch to the battery.
https://jetboaters.net/threads/anot...-dual-battery-upgrade-w-pics.5354/#post-91862

On top of that there are some threads about dual battery setups that I would search for and read, that's where I did most of my research before doing the upgrade. Here's one with some diagrams that @txav8r posted, really good stuff from him on this topic.
https://jetboaters.net/threads/anot...-dual-battery-upgrade-w-pics.5354/#post-91862

Ask questions if you have them and can't find the answers, that's what we are here for!

 

[Julian]

There are advantages to having multiple switches, the biggest being that you can independently control what is ON and what is OFF. The new Yamahas come with the following type of switches (grabbed of google):

The advantage of this setup is that it will charge both batteries off the engines, and that you can combine both batteries if need be, but you can also shut off your start battery with 100% confidence and keep using the stereo while floating, and not worry if your start battery is being depleted.

The other options you have are ON/OFF/Combine single switch, or 1/2/Combine/OFF switches.

The ON/OFF/Combine is your next best bet in a single switch as it still keep both sides separate, but doesn't give you the option of only turning one bank on.

This thread has some more details on this topic too.

 

[synackattack]

If it makes you feel any better about having two engines on one switch, my dual engine AR210 came from the dealer wired up one battery to a single on/off switch.
I just put in a Blue Seas Add-a-battery kit. It was super simple to put in. https://www.bluesea.com/products/7650/Add-A-Battery_Kit_-_120A

From what I understand it keeps the two batteries isolated from each other unless the ACR senses the start battery is full and charging. It then combines so that the 2nd battery gets charged. The only downfall I've read about this system and our Yamaha's is that we don't have a strong alternator. So if you're not spending a lot of time driving the boat around the engines may not finish charging the start battery, so your 2nd battery doesn't get as much time being topped off.

We're normally running on plane for an hour or so each way to the sand bar/island, so for now I've not had that issue.