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Forgive me if this question has been answered already. I tried the search function and didn't have any luck.

I just purchased a 2000 Montauk 17 (Mercury 90 HP 2-cycle) and there is a switch inside the center console that controls the power from the batteries. The switch has an off, one battery and dual battery positions. It is a rather large dial installed on the inside of the front of the CC. The person I bought the boat from told me to turn the switch to off when storing the boat, which I trailer.

What do others do as for setting the switch when the boat is idle or trailered? With it off, can't operate the motor trim or anything else which is a pain. Setting to on might drain the batteries, especially if a CC switch is accidentally hit and turned on.

Also does anyone have or suggest an onboard battery charger for the dual batteries? Shouldn't the batteries charge when running the motor?

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Unless you are running a baitwell or trolling motor, you do not need 2 batteries.

When trailered. Set to OFF.

When you need power, rotate to 1 then when done, rotate to OFF.

The charging of the batteries is dependant on how they are wired with the switch.

Unless you absolutely have to have 2, remove one and replace the switch with a simple ON/OFF switch.

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Thank you. The boat does not have a bait well nor trolling motor and I have no intentions of installing them. Why would the manufacturer ever install that switch anyway? Wondering why it’s purpose.

So there is no need for an onboard charger? I talked to my motor mechanic who is very experienced with 2 cycle motors and he is skeptical about the motor charging the batteries sufficiently. My prior boat was a bass boat with a Mercury 115 hp 2 cycle 20006 and I had an onboard charger for the trolling motor but I’m pretty sure it also charged the ignition battery.

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Is your mech in the profession of selling you something?

80% of Montauk 17 owners run a single Group 24 battery and don't need a charger. Myself included.

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I think he is accustomed to working on freshwater boats and he has never been one to suggest something unless he thought it would be a good idea. He plans to retire at the end of the summer and I can tell he is struggling a bit.

Thank you for your insights and experience with this. It helps.

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You don't need to use a 2 battery switch if you don't have 2 batteries.

You can use a switch that will turn off the only battery you have.
This also has a key for added safety from theft.
https://www.amazon.com/Volt-Battery-D...&psc=1