Charge Your Trolling Motor Battery from Your Outboard Motor

If you are using a traditional battery insulator, it will require to make modifications on the electrical wiring of the outboard for you to get into alternator output.

So, for it to be successful, it needs extra cables to the boat engine but will void the warranty. Battery isolators, on the other hand, they have an inbuilt voltage drop such that your trolling battery and starter battery doesn’t get a full charge.

How You Should Connect

If you want to connect the trolling battery to the outboard motor, you need to use a combiner that will connect between the trolling battery and the starting battery.

If the outboard engine will be running, its the role of the combiner to share charging output together with your trolling battery.

In case your engine is OFF, you will find that trolling battery separate with starting battery so you don’t expect it to accidentally discharge. If you still confuse follow steps and change your trolling motor battery easily.

So, a trolling battery will not have the switches that you have to worry about because it’s completely automatic. So, because there is no voltage drop, all the batteries will have a full charge.

Moreover, there is no heat sink that will get hot or diodes to burn out. Due to its ability to be waterproof, it can work properly in an open boat.

While installing the connections, they are easy with simple steps.

It’s essential to know that there will be no power the moment the engine isn’t charging. So, no power draw for the battery while combining.

You also need to know that one can disconnect this trolling motor battery while the engine of the boat is still running without risking to damage the alternator. When overloaded, electronic thermal shut down will re-start because it’s automated. Open the following link to find the best 20hp outboard battery that you can order online. 


Start by mounting the combiner 100 into a convenient position. It could be 2 feet from the starting battery. However, the combo has to be waterproof and therefore doesn’t need you to cover – its submersible.

However, it’s not essential but try to make the LED indicators of the combiner to be visible. For visibility, it can be a place away from direct sunlight that will also make it cooler.

After setting the combiner, connect the red leads to starting the battery’s positive terminal. For a combiner, the red lead you use doesn’t matter because it works in both directions. However, you have to ensure that the remaining red will not be touching anything not to short out

The other red should be connected to the trolling battery’s positive terminal. When you are done with the red leads, follow the same procedure for negative terminals with black leads.

While making connections to your trolling battery, you’ve to protect from the damages and mostly in the metal boat.

In this connection, you don’t need to use a green wire, so you have to cut it off. You have to ensure that its end doesn’t touch anything and therefore wrap with insulation tape.

While working, the red light isn’t supposed to come on. In case it comes, it means that you’ve overloaded the combiner and will shut down for protection.