Pontoon Boat & Deck Boat Forum

I have a starter battery, and two house batteries on a pergo switch and they're own 3 bank charger and the merc will charge them when running. Now I installed a new 36 volt trolling motor system that is at the other end of the boat from my other batteries and the engine. It has it's own 3 bank charger for charging at home but not hooked up to the alternator for charging on the go. Can someone tell me at a 3rd grade language level how to run a wire up to the batteries for charging them while the motor is running? Thanks

So you're thinking you're going to charge six big old heavy deep cycle batteries with an outboard motor? I know three are possible from personal experience though at times I haft to take extended runs to provide additional time to "get it done". And I'm thinking you're expecting a bit to much from your alternator myself. But I am going to take a backseat a watch to see if others think it's possible.

Bamby wrote:So you're thinking you're going to charge six big old heavy deep cycle batteries with an outboard motor?

yes that's what I want,,,, and please do it at no extra cost and make it convenient and automated with pretty lights and stuff,,, LOL
BTW I should have said the "Merc" was the 130HP I/O version (still not a huge alternater, I'm smelling what your steppin in!)

but ,,,,that's why I came here and posted my question,,,, to see what the smart guys would do to fix the problem,,,, I just wanna fish all day, day after day and not worry about things
a few of the ideas I have floating around are,,,,,
-get a bigger alternator
-get a solar panel to help
-get a VERY LONG extension cord,,,,,

To recharge 5 deep cycle batteries just from your outboard you're going to need a HUGE gas tank and and ALOT of running time and even then I doubt you can ever fully charge them. The alternator just doesn't put out that many amps.

The alternator on my 60hp will keep a few lights running and give a bit of a charge to the starting battery. Everything else runs off the deep clycles batteries. As soon as I unhook my trailer I hook up the onboard charger to recharge everything for the next trip.

Your thread title clearly excludes me, but I'll chime in anyway. Would a little generator be of use here? Something quiet like the little Hondas that are on the market? The nice ones are not cheap, but you have a boat so you are used to that already, right?

Now, hopefully more of the smart guys will chime in as you originally requested.

That has crossed my mind,,,, and I have two gen-sets I could put on-board. A 1000 watt 2 cycle or a 2700 watt 4 cycle. My first concern is running sensitive electronics on them. I know Honda has that part figured out, and makes the cleanest power units pretty much anywhere. But neither of mine are Hondas and I just hesitate to use them. Is there a device I can run between the generator and battery charger that cleans things up and protects the electronics???

You are going to need something like this:

http://www.starmarinedepot.com/minn-kot ... 60-18.html

How long do you motor between spots decides if this is useful or not. You will still need an onboard charger when you are back at your dock or back home.

Another option is just have an onboard charger powered by a large inverter but that is likely the same cost as this.

Is there room for a second alternator on your I/0? We installed second alternator that's 24v on my Grandpa Lund Baron with a 5.7L I/0 that charges the his 24v bank. We found brackets for the second alternator from a car audio site. Might be possible to find a 36v alternator and make a braket for yours maybe. You can also charge a 36v bank off a 12v source using a lot of heavy duty diodes but I really don't like that method. Before the second alternator my grandps use to charge the 24v bank with a Honda 2000w generator and charger.

If your electronics are running off of the batteries then its not going to matter what the sin wave from a generator looks like.

babock wrote:You are going to need something like this:

http://www.starmarinedepot.com/minn-kot ... 60-18.html

How long do you motor between spots decides if this is useful or not. You will still need an onboard charger when you are back at your dock or back home.

Another option is just have an onboard charger powered by a large inverter but that is likely the same cost as this.

this is a interesting/good solution,,, it would require some motor time for sure, but I put on a trolling plate to slow down the main engine for trolling so that would be the time to charge the batteries. Thanks for the link
I have a nice 3 bank charger for when at the house,,,,,

rancherlee wrote:Is there room for a second alternator on your I/0? We installed second alternator that's 24v on my Grandpa Lund Baron with a 5.7L I/0 that charges the his 24v bank. We found brackets for the second alternator from a car audio site. Might be possible to find a 36v alternator and make a braket for yours maybe. You can also charge a 36v bank off a 12v source using a lot of heavy duty diodes but I really don't like that method. Before the second alternator my grandps use to charge the 24v bank with a Honda 2000w generator and charger.

adding a 36 volt alternator might be possible for me,,,, thanks for the idea,,, will look at it hard

crspang wrote:If your electronics are running off of the batteries then its not going to matter what the sin wave from a generator looks like.

i'm worried about ruining the 3 bank charger I use at home, on a dirty running generator out on the lake,
anyone know how to run a test and see how good or bad my generator runs under load?

Could try an inverter/generator. I have a Champion 3100 watt that runs my led tvs and computer just fine. Affordable and pretty quiet. Got one for emergencies at home and to take camping on the boat to run an ac for my tent.

#2 on the second alternator. Can you run a 12 volt and battery selector switch instead of going 36 volt?