Electrical connection to perko switch

[Al Kungel]

I recently purchased a 4 stroke 8hp Yamaha (rope start) and want to use the current generated by the Yamaha to help maintain the batteries on the boat.<br /><br />The boat has 2 batteries, a perko switch (Model 8504) and main motor is a 115 hp Merc.<br /><br />The question is what is the proper way of connecting the electrical output from the Yamaha to the perko switch?

 

[Silvertip]

Re: Electrical connection to perko switch

What are your intentions for the switch? To switch between the two batteries, or switch between the two motors? The alternator on the Yamaha is 6A and unless you run it wide open for hours, it won't add much capacity. If the 115 Merc is also attached to those batteries you need to isolate the two systems.

 

[Al Kungel]

Re: Electrical connection to perko switch

Upinsmoke,<br /> What are your intentions for the switch?<br /><br />To switch between the batteries. I was hoping to utilize the power from the Yamaha to help keep up the batteries while I am using downriggers, fishfinder and the radios.<br /><br />What is involved in isolating the two motors?

 

[Silvertip]

Re: Electrical connection to perko switch

You are ignoring the 115 charging system and I assume you want that hooked to the batteries as well. What that means is you have both engine charging systems feeding a common point. Since the 115 has a much higher charging output than the Yamaha, backfeeding that electrical system my pop the regulator. The cheapest solution and probably best of both worlds is to install two switches. One will be used to switch on-line whichever motor you want to use and isolate the other. That switch will feed the other which determines which battery (or both) will be used.<br />The first switch would be used in reverse fashion (Engine 1 to Bat 1) Engine 2 to Bat 2, and COM to COM on switch 2. Bat 1 to Bat 1 and Bat 2 to Bat 2. You can then run switch the 115 on line for long runs, or switch the Yamaha on line for trolling. This again is just an inexpensive and flexible solution to what you want to do. There are many other more "sophisticated" ways of doing it.

 

[Al Kungel]

Re: Electrical connection to perko switch

Upinsmoke,<br /><br />Thanks for the info.