Dual batteries and switches revisited

[ClassicsIV]

Hello all,
new to this forum and new to my current boat and set up. I have gone back through old posts to keep from asking same questions, but here goes...
I have 2 Yamaha 150 4 stokes as power. Have dual batteries and two Perko switches , each with 1, 2, all, and off positions. boat is a 2006 and all should be factory set up.

Why two switches if purpose is to select between battery 1 and 2 ? Wouldn't one switch do that?
Should I always have each switch in the same selector position? Both 1, both 2, etc?

What are the practical applications of this type set up and how would I get the best benefit?

I was dead in the water last time out and had to get jumped, so I don't think I am using correctly.

Thanks in advance for all the advice.

 

[Outsider]

Re: Dual batteries and switches revisited

I suspect you're wired so that each engine can be supplied from either or both batteries. I also suspect you went dead while at least one switch was in BOTH, right? You don't need isolators, combiners, a house battery,or all that other stuff, you just need to determine how your system is put together and go from there.

I've wired my dual systems so that either battery can be connected to either engine, or to both at the same time. And I reserve BOTH for starting emergencies only, then switch to the best battery by itself. I've also split my electrical load so I wouldn't run the risk of losing everything if I had to completely isolate one dead side.

I prefer to have complete control of my electrics .. agreement is not required.

 

[Silvertip]

Re: Dual batteries and switches revisited

No -- one switch cannot work on a twin engine setup. Why? It's very simple. You cannot run an engine without a battery connected to the engine. Although a two stroke will run without a battery, the alternator and/or regulator/rectifier will fry in a heartbeat. Let's take your situation. Each engine (yours are four strokes) needs a battery to run. So obviously you have two batteries. With one switch, I ask what setting would you run on? BAT 1? Answer is nope, because BAT 2 would be disconnected with the switch set to BAT 1. OK - so lets try BAT 2. Nope - wrong again for the opposite reason indicated for BAT 1. Well then -- it must be BOTH. Nope again. Althought the engines would start, both batteries would be connected in parallel and therefore shared by both engines. So what you say. Well, which regulator (engine 1 or engine 2) is going to regulate the charging system? With all of the electronics in your four strokes, you don't want a confused electrical system. I believe I was told once that the Yamaha rigging manual also says that's a no-no. In fact, if all you have is two batteries, one for each engine, I don't know why you have switches at all other than to accomplish a cross over to start engine 2 from engine 1 battery if engine 2 battery went flat, or vice versa. But since you asked the question, I'm betting you couldn't tell me what switch settings you needed to perform that operation. Please don't take me wrong here -- I'm not being nasty. But that's a very complicated solution to a simple problem. A jump start box is cheaper, easier to employ, and you don't run the risk of screwing anything up. Even a set of jumper cables does the trick. If however, you have more than the two batteries (house batteries for example) then it makes sense as you use the house batteries to start either or both engines.

 

[burroak]

Re: Dual batteries and switches revisited

Take a peek at this schematic. It cleans up your circuitry and provides a stable, elegant solution to your situation. You can ignore the third battery if you wish since it is designed to isolate the boat electrical system.

wx3.cmsquick.com/schematic-f.jpg

 

[ClassicsIV]

Re: Dual batteries and switches revisited

Thanks to all who responded to my post. I was out of town this weekend, so sorry i did not get back to you more quickly.

You are 100% correct Outsider. I had both switches set to "ALL" so now I see why I ran both batteries down. Foolish mistake on may part. I have a handwritten note on a slip of paper from previous owner. It simply said, " when running - ALL, when motor off, drifting, anchored - 2, for emergency - 1.

This will not allow me to answer Sivertip's question of how the batteries are set up for what function, but leads me to guess that # 1 battery may be for starting, # 2 for running electronics, live well, etc. ?? Does this make sense?

Silvertip, thanks for your feedback. Your explanation of why one switch will not work is right on and now understandable. No offense taken. I appreciate your expertise and now it is apparent I have to determine how engines, electronics are set up with the switches so I can provide more detailed information for better feedback. That will be a priority.

burroak, thank you for the diagram, but I can't open. Is it a link to a website or a file that should be attached and open by clicking on the name?

 

[burroak]

Re: Dual batteries and switches revisited

It's www.cmsquick.com/schematic-f.jpg, but to conform with site rules the url has to be disabled by messing with the "www." or putting quotation marks around the url which have to be removed and pasted into the browser-"www.cmsquick.com/schematic-f.jpg".

 

[PondTunes]

Re: Dual batteries and switches revisited

Since we are having a discussion in the electrical forum about switch configurations you might want to take a look here for some more information:
http://forums.iboats.com/showthread.php?t=227833

It sounds like your boat is wired with the two switch setup like NovaII's

 

[tommays]

Re: Dual batteries and switches revisited

i have seen posts in the Yamaha forum that say the yamaha rigging guide REQUIREs that the motors are on different battery banks


Tommays

 

[ClassicsIV]

Re: Dual batteries and switches revisited

Thanks all for your help. I know I have a better handle on things than I did a week ago. I need to get to the boat to verify how everything is wired. Thanks to burroak and PondTunes for the diagrams. That helps much and I did check out the thread on the electrical forum. That is where I should have posted to begin.

Great first experience with the forum. Thanks again for all the expertise.