Author Options:

Can two electric trolling motors with different propellers and maximum RPMs be used effectively on the same boat? Answered

I am building a solar powered electric boat. I want to use more than one motor on the transom. I was wondering if using two motors with different maximum RPM, power, and propeller shapes was possible? Would the propeller of the less powerful motor just add drag or would it add power? Obviously this isn't very specific, but I'm really looking for an explanation or proof of concept. Thanks very much in advance community!


A propeller will provide thrust up to the point where the boat is overtaking its ability to push water backward -- after that, it's just drag. So the slower motor is at risk over being overrun by the faster one -- but that depends on all the other variables you mentioned. And unless the difference is a large one, it seems unlikely to become a problem. Of course, as Re-design pointed out, if they're pushing alongside each other you're going to tend to skew. But if the more powerful one is at the bow and the less powerful is at the stern, it might be workable. Try it and report back?

i'll probably forget to report back, but we'll test it and see what happens before the lakes freeze up. thanks for your help!

I honestly never even thought about doing something like this with two motors. I was actually just looking at electric trolling motors for sale to replace the old one on my boat, so maybe I'll think about trying something like this. What other modifications did you make to your boat to make it solar powered?

Sure as long as one of them is continuouslly variable in speed. Or if you put them very close together you the difference in output won't turn the boat too much. One will be doing more work than the other but both will contribute to the load.

great! i'll suggest it to the team. actually i was planning on using three motors, one a six horse in the middle of the transom, and two trolling motors of equal power on either side. thanks a lot!

if u wanted to get really cool, put two on eacb side (sorry im a landlubber i dont know my boating terms) for turning, two on the back, and one in the front.

or just be really cool and put a sail cuz sailings more fun.

as to solving your problem: just put them close together, and bend the thing that turns the boat, but the only problem is that all your force wouldnt be forward, and it would have a weird motion path...