How Long Can You Safely Run A Trolling Motor On High Speed??

[The Rooster]

I just got a new Minn Kota Edge 55 trolling motor and I'm wondering how long it can safely run on high speed before it damages the motor?? Recently I spun a prop hub on the water on my outboard and had to rely on the trolling motor to get headed back to the ramp, so you can imagine we ran it on high for as long as we could after that. Can this overheat the motor doing this??

I know I'm going to regret telling this story but here goes. Maybe you all will get a kick out of it.

I knew that outboard motor was having some difficulty shifting into gear when I bought the boat. It slowly got worse over time. Thought it was just a gear dog going out and would need a rebuild in the lower unit eventually. I just kept using it though since I never stray far from the ramp most times anyway. Figured trolling power would get me home if needed. I had a Minn Kota Power Drive 55 trolling motor and it is supposed to maximize run time from the battery so I never worried because I had a good, strong motor that was really efficient, a spare prop, and tools to change it if needed. Always thought the battery would be my only concern after maybe 8 hours of fishing and then having problems so I have two onboard just in case. This way all my bases are covered........or so I thought.

So one day the outboard finally gives out and we're on electric only. We start trolling back, about a mile or more. On the way back to the ramp after losing outboard power the trolling motor suddenly took a dump on us as well and we had to paddle for about an hour before we finally made it. The battery was still up so that wasn't it. After we got back to the ramp we looked at the motor. We think it was the result of having the prop shaft bent when we got stuck in some shallow water while retrieving a lure. It now wobbles when turned by hand, and only will turn a half turn now on its own, and then just stops and hums loudly. What was strange is that it ran fine for a long time after we got it unstuck, and then suddenly just crapped out in 30 feet of open water later after we ran it for 30 minutes straight. I believe the problem is related to the shaft being bent but since it ran so long after that it makes me wonder.

Anyway, now the boat is at the marine shop getting repairs and I got a new trolling motor waiting here at home when it gets back. I want to avoid any problems. Normally I don't run the electric motor for long periods of time but I'd like to know I could if needed. As for repeating what happened to the last motor, I think from now on I'll consider a $500 plus motor more valuable than a $5 bait and just break off. It's funny (not really), but this is exactly the same thing I was just saying to my son-in-law as I was retrieving his bait from the stump in shallow water and that's when we suddenly got stuck in its roots. I think that's when we bent the prop shaft right then. I would have thought the prop would have broke first, but apparently not.

[moguy1973]

I wouldn't think it'd hurt it one bit. The motor is down in the water so it's being cooled the whole time while running.

[FourCorners]

I think your motor would be fine. If you want your batteries to last, I'd try not to discharge them past 60%. Do you have the batteries in parallel?

[The Rooster]

No, the batteries are actually running separated. I keep one for starting the outboard, the trim motor, and electronics, and the other is just for the trolling motor but I do have the bilge pump on it too, but it's nearly never used so it's trolling motor only really. I probably should parallel them but they are not the same age so I figure one is weaker than the other and I believe that paralleling unequal batteries will drag the stronger one down. So I've been told. I also have a two bank onboard charger, a Guest brand with dual 5 amp banks. I think I remember that I could put both banks on one battery but I can't be sure now, and can't find the manual to check, so I just leave the batteries separated so each bank charges one battery. If I parallel them then that would also parallel the charger banks. I think that's ok though, but I want to make sure before doing it.

[BKeith]

The trolling motor will run on max a hellavalot longer than the batteries in the boat are going to last. You give me the impression this is a 12 volt TM. On a very good, fully charged group 29 battery that's 120 Amp hour, about the most you are going to get out of the battery with the TM on high is a little over 1 hr to 1 1/2 hours max. Running a smaller battery like a group 27 is going to cut that time back even more, and if running a group 24, you may probably won't get an hour. Remember, I said a like new, fully charged battery, not one you've been abusing for a while or have already run the TM a lot before that.

The maximizer circuit greatly extends run time when using the TM on the slower speed settings, as you increase the TM speed, it becomes less efficient, up to the point it's on high and then it's basically doing nothing to help increase run time.

As for the bent prop shaft on the motor, take the prop off, put a steel nut on it, turn the shaft so the bend is facing up and give it a firm tap with a hammer to bend it back down some. Spin the shaft and see how much it wobbles. Keep doing this until most, or all the wobbles is gone. After a few licks with the hammer you will get a feel for how hard you have to hit it to bend it back a little at the time. I've done a dozen of them over the years, and stuch the whole TM in the fork of a tree to straighten the vertical shaft a number of times.

It the TM just suddenly stoped like you turned the switch off, I will bet you tripped the circuit breaker. That TM needs a 50 amp breaker to run it very long on high.

If you start connecting your cranking battery in parallel with the TM battery, you are asking for trouble. You will not be a happy fisherman the first time you are back in the middle of nowhere and go to start the motor, just to find you've run the battery down to far for it to crank the motor over.

[The Rooster]

That's one reason I keep them separated also. I don't want a dead cranking battery.

The circuit breaker is auto resetting, but it never tripped. The motor just whines loudly but won't turn. I tried the hammer trick but had no luck. I will see about ordering a replacement armature but I'll sell it after that. Got a new motor now.

[Jig Man]

Rooster you are correct in keeping the batteries seperate.

I run my trolling motor on what ever speed it takes to do the job. Sometimes in current or wind I'll have it cranked up for hours and hours at a time. It has been my experience that you can't harm a good trolling motor by run time. Like stated, the battery will give out before the trolling motor even starts to be over worked.

[cody161]

I have ran a 45lb thrust trolling motor on high for well over 1 hour without running the battery all the way down. The battery was a 29 and it wasn't brand new either. I broke a steering cable roughly 4.5 miles away from the ramp...It wasn't a fun day.