Powering a 24V trolling motor from mains

george92

Recruit
Joined
Jan 10, 2019
Messages
1
Hi all,

This may be a bit of a strange request, but I want to power a 24V 100ft/lb (max amp draw 55A) trolling motor from mains rather than from batteries. I am experimenting 3d printed propeller designs for a university project, so the motor will only be used indoors.

I could just use two 12V leisure batteries in series, but this seems pointless if I'm not going to take the motor out on water. I was thinking it might be cheaper just to run it from a power supply. Or would it be possible to power it directly from a 24V battery charger? If anyone has ever tried this, any tips would be greatly appreciated. Thanks!
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,592
First things first. Welcome to iboats, we like new members...:welcome:

Your project sounds interesting for sure. It sounds like you are needing a heavy current power supply capable of supplying at least 55 amps. 65 would be a better choice to give you a little inrush current protection.

Why you want to do is build one using a variable LM317 regulator. I say variable so you can test how the prop would work with a battery draining situation as well. However you will need a very large transformer to get that high of current outputs.

You could gang a few transformers together to get that need, but then you equally have to use a lot of parelle power transistor to allow that current as well.

Can that be done? Yes it can. But it is going to take some clever designs to get you there. Maybe a transformer out of a MIG or TIG or even a Stick welder would give you that transformer option. But then you need some heavy duty rectifiers as well. The LM317 is the heart of the circuit to control the power transistors. Could even use MOSFETs as well.

I would think the two 12 volt trolling motor batteries would be the easier setup. Just keep them charged and it should be the easiest workable setup unless you want to build a high current 24 volt power supply. JMHO
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,751
Hi all,

This may be a bit of a strange request, but I want to power a 24V 100ft/lb (max amp draw 55A) trolling motor from mains rather than from batteries. I am experimenting 3d printed propeller designs for a university project, so the motor will only be used indoors.

I could just use two 12V leisure batteries in series, but this seems pointless if I'm not going to take the motor out on water. I was thinking it might be cheaper just to run it from a power supply. Or would it be possible to power it directly from a 24V battery charger? If anyone has ever tried this, any tips would be greatly appreciated. Thanks!

What is the planned duty cycle?
Do you plan to run the motor constant for several hours or 1 to 2 hours and stop?

If constant, build a 55 amp + power supply
If for 1 or 2 hours then use bats and a smaller charger
 

DouglasW

Petty Officer 1st Class
Joined
Apr 20, 2018
Messages
269
Yeah, 2-12v batteries with a charger to keep them up is the best bang for the buck. If you really want a power supply, a used HP Agilent/Keytech 6032A might do it for about $500.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,546
two batteries with a good charger is about half the cost as a 65 amp or more power supply with a bank of capacitors (you need a power supply with the capacitors for the in-rush current)

the batteries and charger can also be scrounged up used if needed and your in it for only about $50
 
Top