Charging 24v trolling batteries from outboard

Have 2001 fishing pontoon with 115HP Merc. What is best method to charge starting battery and two 12V deep cycle connected for 24 volt trolling motor. If I install an isolator (which one?) is it necessary to disconnect the + to - between the two deep cycle batteries while running the engine?

Re: Charging 24v trolling batteries from outboard

Some one will chime in with more knowledge than me, but it is is my understanding, the best way to wire it is to not hook up your trolling motor batteries to your engine does not enough to properly charge them.Charge them with a good slow charger.I've been around alot of tournoment bass boats and have never seen it done any other way.Some one else may give you the science behind it.<br /><br /><br /> Jim

Re: Charging 24v trolling batteries from outboard

It can be done. First, you have to know the difference between series and parallel. Series is positive to negative, which is adds voltage. This is how you get 24V from two 12V for your trolling motor. Parallel is positive to positive, and negative to negative. <br /><br />If you have them all hooked in parallel, you can charge the whole bank at once. I recommend isolators to avoid any danger from differing voltages.<br /><br />Now, on that note, your motor is not the best way to charge a deep cycle battery. They like to be slow charged a certain way for maximum efficiency and life. So, yes it is possible to charge all three batteries from your motor, but it's not the "best" way.<br /><br />I can't give you specifics on how much it will affect your battery life. It may be nearly insignificant, or it may have a severe impact. But rest assured, it WILL have an impact.