Best trolling motor

[upnorth61]

I have an older 17 foot fiberglass fish and ski with a 115 Mercury Tower of Power. The motor has died a couple times while out on the lake and I'm wondering what size trolling motor would be good to get back to the landing should it happen again. Thanks!!!
 

[leech~~]

1 hour ago, upnorth61 said:

I have an older 17 foot fiberglass fish and ski with a 115 Mercury Tower of Power. The motor has died a couple times while out on the lake and I'm wondering what size trolling motor would be good to get back to the landing should it happen again. Thanks!!!
 

Welcome to the forum.

Pretty heavy boat.  Are you looking for a gas of elc trolling motor?  

[BobT]

On 4/3/2022 at 5:51 PM, upnorth61 said:

I have an older 17 foot fiberglass fish and ski with a 115 Mercury Tower of Power. The motor has died a couple times while out on the lake and I'm wondering what size trolling motor would be good to get back to the landing should it happen again. Thanks!!!
 

Unfortunately, that's kind of a loaded question. It depends on how far you'd have to go for starters. Your thread title asks about trolling motors and as Leech has already asked, are you talking electric or gas? An electric trolling motor will require a pretty substantial battery pack if it is going to get you any distance and unless you go with Lithium that will add quite a bit of weight too. There are also electric outboard motors that are designed for things like sailboats, dingies, etc.

 

I found one called a Spirit 1.0 Plus that is rated for the equivalent of approximately 3hp. Coupled with a 1275Wh lithium battery (approximately 20 lbs.) they say it could drive a 12' aluminum boat with one person and one battery (no other gear) at a speed of about 6,2 mph for up to 7.8 miles. Add other factors like boat weight, outboard motor weight, gasoline weight, weight of passengers, gear, fuel for your gas outboard, live well full or empty, electronics, ambient temperature, and so forth your range would be considerably less. Here's a link if you're interested. https://www.epropulsion.com/spirit-1/

 

Just for fun let's consider a 36v 101 lb. Minn Kota motor using three fully charged 105ah wet cell deep cycle batteries. According to Minn Kota specs, this motor will draw about 46A at full power and I would expect it might move your loaded boat up to about 2-3 mph. Side note - more thrust does not equate to more speed. More thrust is required depending on load so a heavier boat requires more thrust to move it through the water. Boat speed comes from prop pitch, prop diameter, and prop speed. 

 

We can estimate that you might get 2.28 hours of run time from a fully charged 105ah battery. Basically take the ah rating divided by the current draw so 105 / 46 = 2.28. Note, this would be in a perfect world with a 100% efficiency result. Actual run time will be reduced due to motor inefficiencies, prop slip, and so forth.

 

Assuming it would move the boat at 3mph and at 100% efficiency you might get a little over 6-3/4 miles with no wind. Any wind from any direction except behind you will reduce this a lot. And, of course, how heavily your boat is loaded down will affect this considerably too.

Edited April 6, 2022 by BobT

[gim]

Most people don't buy an electric trolling motor with the intention of using it as a backup source of power when their main outboard dies.  That's not the purpose.

 

I've had to do it once many years ago.  Took me almost 2 hours to get in on a relatively small lake.

 

My advice to you is get a more reliable outboard and make sure it starts and runs properly every time you expect to use it.

Edited April 7, 2022 by gimruis

[BobT]

8 hours ago, gimruis said:

Most people don't buy an electric trolling motor with the intention of using it as a backup source of power when their main outboard dies.  That's not the purpose.

 

I've had to do it once many years ago.  Took me almost 2 hours to get in on a relatively small lake.

 

My advice to you is get a more reliable outboard and make sure it starts and runs properly every time you expect to use it.

Could consider a gas kicker if it's a concern but I agree, I would not consider an electric as a backup. I too have done it though on a small 650 acre lake and in my case I had to go against the wind so it took a little while with my Sylvan 1600 Adventurer and my 55lb electric. My brother-in-law had some issues with his Lund Mr. Pike with a 115 Yami and had to rely on his 80lb Minn Kota electric to go about 2 miles and this was after using it quite a bit throughout the day so it was touch and go. Got back to the launch only to discover it was just a loose battery clamp on his starter battery. It happens.

Edited April 7, 2022 by BobT