Is 30lbs of thrust enough?

[woondirch]

Hello,
I'm new to boating, please correct me if need be. My girl and I picked up a 1970 12ft sea king aluminum boat. It has a few leaks, but thanks to the info on this site I'm able to deal with it. My question is : as far as battery life is concerned, should I go with a 45lb thrust, or the much cheaper 30lb thrust motor?
I have an old 2hp clinton, but it needs a bit of work. I would like to get out on the water as soon as possible, while I'm working on the old clinton.
I took the boat out on Canyon Lake, AZ with oars as an experiment and the wind really was a factor.
I would like to buy an electric motor soon, I just do not have any experience of using a 30lb thrust motor. or any motor for that matter. I do like to fish, but it also will be a pleasure boat. (as in enjoying the view)
Is 30lb of thrust enough?

 

[Jay D]

Yes it is enough, especially if you have a gas outboard too. I have a 30 on my 16' and it pushes it fine. Mine would be better for me if mine had a 36" shaft but it works fine.

 

[JeffChastain]

I now have two trolling motors on my boat, but I was just running a 27 lb M-K Turbo on my 14ft shallow v, and really it wasn't enough. running against the wind was difficult at times, and really running at full speed with the wind was too slow for me. Took forever if you're fishing backwater or a bigger lake.

 

[redbug]

bigger is better when it comes to a trollin motor i would o with the 45.. if the wind will be happy you have the extra power

 

[user 6672]

bigger is better when it comes to a trollin motor i would o with the 45.. if the wind will be happy you have the extra power

+1

 

[bcbouy]

i run a 35 on my 14 ft. v. along with a yamaha 15. its good for trolling ,but any electric sucks in heavy wave or strong wind,and will kill the battery fast,and i run dual deep cycle marine 27's.

 

[CodyPomeroy]

I bought a 50lb thrust for my 12'. I figured I could use it when I get a bigger boat. On calm water, with no wind, you could almost ski behind it. I haven't had much trouble with wind, but I fish in a river most of the time and if the river is up it doesn't do well straight into the current. As others have said, get the biggest you can afford.

 

[vahunter]

I have a 15ft with a 32lb and is perfect in most situations but with windy and/or current it does slow it down a good bit. I'm happy with mine but if I had the extra money id get a bigger one. I generally wont do much fishing on a real windy day though. If you plan to use it a lot, be in high current, electric motor only lakes, or even plan to eventually get a bigger boat... Id definitely get the bigger one.

 

[shawnfish]

id go with the 45, if it were dead calm conditions the 30 would be fine. you could go with the 30 and carry 2 batteries so when the wind picks up you'll have a spare when the battery dies. but even with 2 batteries and wind you probally wont get nowhere fast so if speed dont matter you could save some money and go with the 30 and 2 batteries. my .2 cents worth..........

 

[woondirch]

Thank you everybody. This site rocks. I guess the second part of the question would be, What do I have to do to make my electric motor run for 4 or 5 hours?

 

[FuzzyGrub]

I guess the second part of the question would be, What do I have to do to make my electric motor run for 4 or 5 hours?

A DC battery is typically rated at a 25amp draw. Typical ratings are 160-200 minutes. The physically larger size DC will typically have a larger rating. As a general rule for 12V Trolling Motors: for every 1 pound of thrust, uses 1 amp of current. In reality, the amp draw depends on the motor, the boat, and the load.

This will give you a rough order of magnitude. Your milage may vary.

Assuming a 180 minute reserve battery, and constant use:
5lb Thrust: (25A * 180) / 5A : 900 minutes
10lb Thrust: (25A * 180) / 10A : 450 minutes
20lb Thrust: (25A * 180) / 20A : 225 minutes
30lb Thrust: (25A * 180) / 30A : 150 minutes
45lb Thrust: (25A * 180) / 45A : 100 minutes

So it all comes down to how you use the trolling motor. If you are just going to run on constant high setting, you will need multiple batteries to go 4-5 hours. On the other hand, if you are using the lowest setting, one battery is fine.

For electric only power, bringing a 2nd battery is always a good idea. Whenever the 1st starts to feel rundown, time to switch batteries and start heading back.

 

[bcbouy]

or you can run 2 in parallel or series,depending on the motor voltage. also the more amp hrs the battery,the heavier it is,usually.if weight is a concern.

 

[woondirch]

Thanks for the info, I'm trying not to overspend, if you know what I mean.

 

[Sharpix]

From a 12' electric only fisherman.

Get a 55 if you can, better if you prefer those "digital" or "maximizer"models from MK or MG. They save battery at the middle speed ranges by using electronic speed controllers. Minnkota Maxxum have built in battery gauge. Very useful!

The cheaper 5-speed preset models really suck. They use coils to lessen the current for the slower speeds, killing battery, making unecessary heat, blah blah blah.

A solid 55lbs digital model, 12V can serve for most of the tasks, and even have a bigger propeller *more efficient* than 45lbs models.
Spend your money wisely, one buy for many many years.

 

[rusty.hook]

Go with the 45 or 54lb motor. Because the more yall fish on later, the more weight yall are going to add to your boat. I have an alum. 15' G3, semi-v with a center console, lots of tackle, a cooler with four 32oz bottles with frozen water, 2 ol farts that go about 230 each and 2 batteries, 6 gallon gas and I can go all day with mine and still have plenty of juice left. I have a 55 lb hand operated Motor Guide troll motor with the fold out mounting bracket on mine. The key to all this, as soon as I back into my boat stall next to my house, I plug in my on-board 6 amp charger. Keep the batteries charged, that's the key.

 

[shawnfish]

are you running it off the bow or transom? it matters, i think most would agree. when windy or calm your way better off with a bow mount, easier to pull than to push.

 

[woondirch]

Thank you everybody. I had thought I would use a transom mounted motor, but I may reconsider. Pardon the pun but it is an "endless sea" of information. Good times though, I haven't had this much fun tinkering in a long time.

thanks fuzzygrub for the info table, very helpful.

cheers