Charging TM Battery with Outboard

[fissure_man]

Does anyone use their outboard engine to charge their trolling motor battery(s)?

If yes, how do you have it set up?

Pros/Cons?  This seems like a no-brainer to me if it can be done without risking leaving your cranking battery uncharged.  I guess a possible downside would be potentially hurting your deep cycles with too high a charge rate.

I’m running a 12V 55 lb thrust motor, and over the course of a day I can easily run the battery down to the point of reduced performance on a windy day or when chopping through weeds.  I’m sure having an old battery isn’t helping me, but still. 

If I’m camping out with nowhere to plug in, charging my TM battery from the alternator would be sure be nice.  I’ve been known to swap batteries and pull-start my outboard to achieve the same thing.  A switch at the console would be much easier

Any thoughts?

[fissure_man]

Looking into this a bit more, I see there are some aftermarket systems available to achieve this.  Has anyone tried them?

[iabass8]

There's a new product from Minnkota that does what you're asking. I've never heard of anybody doing this or even wanting to do it due to how long good deep cycle batteries last and having a 24v or 36v system. I'm sure somebody has done it. However, if your TM is capable of running a 24v system, your battery issues will go away will likely go away...

[riverbasser]

never thought of this but seems like you could make something pretty easy with a starter solenoid or some refer to it as a starter relay. Just put it inline on the hot wire between both batteries and run an igniter wire with a switch in the dash.

[fissure_man]

On ‎7‎/‎12‎/‎2016 at 5:51 PM, riverbasser said:

never thought of this but seems like you could make something pretty easy with a starter solenoid or some refer to it as a starter relay. Just put it inline on the hot wire between both batteries and run an igniter wire with a switch in the dash.

Yep, for a 12 V system it seems like it should be pretty straightforward... which makes me wonder why hardly anyone does it...?

On ‎7‎/‎12‎/‎2016 at 5:23 PM, iabass8 said:

There's a new product from Minnkota that does what you're asking. I've never heard of anybody doing this or even wanting to do it due to how long good deep cycle batteries last and having a 24v or 36v system. I'm sure somebody has done it. However, if your TM is capable of running a 24v system, your battery issues will go away will likely go away...

Fair enough, but for a small boat 1 or 2 extra batteries is a lot of weight and compartment space.  I'm surprised there aren't more 12 V users who've tried something like this.

Thanks for the replies. 

[Scorchx1245]

I use to run a manual switch on my old boat, when I start the motor open the battery compartment and flip a switch that linked both bstteries. Course this was a 454 I/O.....

[Wayne P.]

Yandia Trollbridge has had that system on the market for many years.

[desmobob]

I do it.  I have a light aluminum boat (Tracker Pro170) with a 12V trolling motor and sometimes fish for a l-o-n-g time.  I bought a Minn-Kota "Alternator" device that directs your outboard's alternator output to the trolling motor battery as soon as the cranking battery is at full charge.  It is kind of bulky and heavy, and a bit of a chore to wire up, but it works well to help keep my single trolling motor battery going all day and into the night.

Tight lines,

Bob