A question about charging systems.....

[sssports]

Hellow everyone,

A short story first, I have purchased and set up some LED lighting for my boat, not premade products, just purchased the LED modules and circuit boards, and am in process of making a underwater fish attracting light using LED's. Long story but I have two lawn tractor batteries, and have tested my LED light setup using one of them and it will power all the LED lights for days, so I plan on using this lawn tractor battery exclusively for this purpose.

My outboard is a Johnson 70 VRO and has the charging circuit back to the main deep cycle marine battery, I would like to have charging take place for both the LED light battery a trolling motor battery and the main battery at the same time while running, but common sence tells me that this will also draw on the lighting/trolling battery during starting if hooked up without some kind of switching.

Since I am a first time boat owner, is there a commercial product to charge multiple batteries, without using all of them during the starting process ?

Thanks for all your help
Marty

 

[rickdb1boat]

Re: A question about charging systems.....

This should give you an indication of what you will need to do. Others can explain further better than I can...

http://www.boatfix.com/how/Ele2.html

 

[WillyBWright]

Re: A question about charging systems.....

You can get an Isolator. But your charging system is made to charge the starting battery only and is not particularly strong. For the same money, you can get a solar charger for the tractor battery and never have to spend another cent or bit of effort to keep it charged.

 

[sssports]

Re: A question about charging systems.....

Vice Admiral....

Thanks, I work construction and do electrial work, so the link posted with the wiring diagrams (thanks!) didn't faze me a bit, but looking at the cost of the switches and the isolater .....I immediately decided I would either one chage it when I got back home, or two use an alternate method as you suggested like a solar battery charger.

I wasn't aware that the stator was very limited on this motor as far as output, and thanks much for that information.

This place is great, thanks for all the help !
Marty

 

[Silvertip]

Re: A question about charging systems.....

Solar chargers are not chargers -- at best they are maintainers used to maintain a battery in storage. They are way to expensive and way too large for small boat applications, and a target for thieves if you have one with enough capacity to actually serve as a "charger".. Your engine alternator will do just fine keeping the tractor battery charged. You can use EITHER a battery switch OR an isolator -- there is no need for both. In fact, with LED lighting, I would not even use the tractor battery if the starting battery is a dual purpose starting/deep cycle battery. If that battery is of sufficient capacity, it will handle the load and work just fine. If you insist on two batteries and want isolation of the tractor battery, head to Radio Shack, buy a high amperage diode and install it in the positive charging lead of the tractor battery. This will prevent current draw from that battery during starting, but prevent the starter from drawing from it. A battery switch works too -- do a search for battery switches or just buy one right here on IBoats. You would need one that has the OFF-BAT1-BAT2-BOTH settings. If you want an even simpler set-up, install a two-pin connector off your main battery. When the engine is started, plug in the tractor battery. Just remember to disconnect it back at the dock or when running the lights and prior to starting the engine. You could even use a contactor or relay setup that disconnects the batteries when the engine is off. Install a momentary switch that when pushed AFTER the engine starts, latches the relay and connects the two batteries. When you kill the engine, the relay drops out and automatically disconnects the batteries. Simple and cheap.