Can some one please explain (like you would a 10 year old) what the diffrence is between running a trolling motor on 12 or 24 volts.

And is a 42 lbs motor stronger than a 3hp motor? I have recieved mixed results on this one.

Mil Gracias

TM's up to say 50lb thrust require a 12 volt power supply ( one battery). TM's from say 50lb to 80lb require a 24 volt power supply ( two batteries). I run a 101lb which requires a 36 volt power supply ( three batteries). Need single bank charger for 12v, dual bank for 24v, triple bank for 36v. Some use an extra bank to charge cranking battery. Suggest more power than you need to compensate for wind, xtra weight, etc. Never heard of a 3hp TM. Maybe, a stern mount? Can't help there. I would use a 42lb on a very light boat such as a jon boat. Hope this helps.

David
www.davesguideservice.net

A million thanks David... A friend gave me a Motorguide Brute that has a 12-24 volt switch but it will only work flipped on 24 volts when hooked up to a regular trolling motor battery. Yes the 3hp was a stern mount that I had rigged to use in the front I was just wondering why they would call it a 3hp motor instead of classifing it as a pound rated motor. I am using this 42 lb motor on a 17 foot tracker I think it should be fine.

WOW!! I ran into a similar or related problem this weekend. I hope you don't mind if I add to this post (I may need to add my own).

Why do trolling motor plugs (both male and female) have 3 wires (or does some equipment use all 3 wires)?, when you only use two of them, one for negative and the other for positive? Black is for the negative terminal, but why is there a blue and a red/orange?

My trolling motor is 24volts, and it only has 2 wire running from the motor. A black wire (for negative terminal on battery) and a "red stripe on black" wire which must be for the positive terminal run in series through two 12 volt batteries.

After having all the real problems worked out on my trolling motor, Minnkota had southwest parts and service replaced the 72lb thrust motor with an 80lb thrust head (now the thing can knock me off the boat if it is pointed either to the left or right and I am not paying attention (preparing to throw the net). I decided to move the trolling motor batteries from starboard battery compartment to inside the cuddy, but I left the previous wiring that runs up to the trolling motor plug on the bow. I purchase 7' of 4 gauge wire from "Boater's World", and solder (followed by liquid tape and shrink tube...the proper way to rig wire that is to be used in saltwater ) this to a new plug, and ran this through and into the cuddy to the batteries. Until Saturday night, I had not been able to get my trolling motor to work, and I thought it could have been the batteries (so I purchased new batteries). It turns out that AlStar Marine wired up everything to use the 12Volt plug.

The instructions from my new ATTWOOD plug indicate that for 24volt, use the blue wire (there is a black, orange, and blue wire). Other than not using liquid tape or shrink tube for waterproofing, I don't know of a problem with this, unless there is a need for the 12volt receptor on the plug. I recall seeing trolling motors indicating 12/24volts maybe it only uses 12 volts during non high demand periods (which might make the batteries last longer). Why would they provide 3 wires. What type of plug is used for 36Volt trolling motors (one with 4 wires??).

12 volts at 40 amps equals 24volts at 20 amps equals 36 volts at about 13 amps. Your trolling motor works more efficiently at the higher power requirements if it is running higher voltages.

Trolling motor plugs typically use more than two prongs because although a single voltage trolling motor needs two wires, some use two voltages like a 12/24 or 24/36 volt trolling motor. They require three wires. One negative and one positive for each of the positive voltages. A four pronged plug can also allow the user to charge batteries from the front of the boat using the trolling motor plug. That was more common earlier and is not used much anymore. It was also less efficient and was somewhat problematic.