Hi,

I would like to add a trolling motor to my kayak. Newport vessels offers a 36lbs and a 55lbs options and the price difference is not a concern...  I would like to use it with a 50ah lithium battery to save weight (rigging is a pain always). The kayak is an old town 106 PDL and has a full capacity of 500lbs. Assuming that I'm fully loaded (to be safe as I'm not that fat) what thrust would you recommend?? If Jeremy Clarkson taught me anything was that more power is better but I don't know if it applies in this situation. Are there any other considerations that I'm missing???

 

thanks for the help. 

 

 

If price isn't a concern, I'd probably go with the 55lb.  However, it will eat that 50ah battery quicker at high speeds than the 36lb version.  But you'll have more thrust should you ever need it, and you won't have to worry about wishing you had more. 

 

Realistically, 30lbs of thrust is plenty for most any kayak in most any situation.  kayaks are small and lightweight.  And the general rule of thumb is 2lbs of thrust for every 100lbs of weight.  So a 30lb trolling motor should be sufficient for a 1,500lb kayak, which is bigger than anyone uses.  The speed limit of a kayak usually has more to do with the hull design than the size of the trolling motor.  So you rarely gain speed by going bigger.  Or if you do, it's a tenth of a mph or so.  

 

So the main advantage is just knowing that an upgrade won't do you any good.  Plus it won't bog down in the weeds or current as easily.  If you want more speed, I'd look into an electronic outboard, like a Torqeedo.  They're basically trolling motors, but they're designed to operate at much higher speeds.  Around 3.5-5mph would be the max I'd expect from a trolling motor.  But a Torqeedo might get you double that, depending on the model you get.  

Newport is taking a chunk out of Torqueedo business!  i am seeing them more than i see the torqueedos these days.  all the guys i talk to run the smaller motor on a bigger 100aH battery for all day power.  i considered it, but watching my friends dick with the extra hardware, is flattening my enthusiasm for it all.  

If you won't be pulling skiers (?) the 36 lb will do fine. My dad had a 17' aluminium bass boat when I was a kid and it had a 28 lb. thrust bow mount trolling motor because my dad was a notorious cheapskate regarding fishing equipment. It was fine until the wind kicked up, but I'm sure that boat weighed north of 700 lbs.

I ran a 45lb thrust with a 35ah battery on my last kayak and could fish all day as long as I stayed off the highest setting.

55lb seems a little excessive for a kayak and a noticeable weight difference vs the 36lb.

 

In my mind, 36lb thrust paired with a 50 ah battery would be ideal.

Also be aware that running the motor on high for long periods is not recommended, wiring gets hot.

Gera,

     I run a Torqueedo 1103AC on my Hobie PA14.  The PA14 is the tank/semitruck of the kayak world especially after I load mine up.

    The 1103AC is rated at 155lbs of thrust. It's supposed to be the equivalent of a 3hp motor. I very seldom run it at full throttle. I can do about 6.5 mph wide open carrying a tournament load. Including me, batteries for live scope, 93SV and trolling motor, and too much gear and tackle to mention. I'm probably pushing 500 lbs. If I back off the throttle and run about 5mph I am running about half power. 1100 watts is full throttle.  At 450-500 watts I'm cruising at high 4's to 5mph.  

     I really like the Newport motors. They do a lot look like a Torqueedo knock off,  I'd check the weight difference between the two (36lb and 55lb thrust).  If it is minimal I'd go with the higher thrust motor.  Having more power IMHO is not a bad thing to have.

     One of the reasons I went with Torqueedo was because it included the battery in the motor purchase. It was a complete system with remote throttle control unit (it displays battery percentage remaining, speed, calculated range remaining and power usage).  battery ( 29volt / 31amp hour), battery charger and motor.  Newport wasn't in business yet when I bought or I might have very well went that way. 

     Go as high as you comfortable can battery amp hour wise. 50+amp hour would be fine for most day trips unless your looking to make long runs at higher speeds.  You could get two 50 amp hour batteries and have a back up battery.   A lot depends on how long your going to fish, how far you want to travel on the water. Do you want something that might be able to go a couple of days or trips between charges? Maybe do some remote overnight camping? Are you going to run a fish finder, navigation lights, power anything else off of the same battery?

     There is a lot of advantages to having a sweet electric motor set-up on a kayak that makes it so much more fun and versatile.

     I don't think you can go wrong either way 36lb or 55lb thrust. 36lb won't eat the battery as fast at full throttle as a 55lb will. A 55lb will use less effort to get the same job done and have power in reserve if needed. 

     The competition is really heating up in the lithium battery market. More companies making batteries, technological improvements and prices are coming down. Check for warranty. I have Dakota Lithium 23 amp hour for my live scope box and they say 11 year warranty on it. I've got a FPV 17 amp hour for the 93SV unit with a one year warranty.  The Torqueedo is two years, 

Good luck in your hunt!

Fishingmickey

Not quite the same but I run a 55 MK on a Bass Raider with a 100Ah lithium, I fish for about 6 hrs at a clip, mostly slow trolling or stopped, maybe 1 trip around a 200 acre pond. I use less then 10%, or 10ah worth of juice. In hind sight I could have easily gotten away with a 50ah battery and saved half the $ and weight.. Your kayak is a lot more aerodynamic then my tub.

7 minutes ago, padlin said:

 Your kayak is a lot more aerodynamic then my tub.

Lol, true but those Raiders are as stable as a Bass boat.

Which is good as one nears 70.

Go with the highest thrust your bnoat and budget can handle.  Yes it will burn more battery at full throttle but you also won't have to use as much throttle to maintain the same speed as you would with a lower thrust version.  

 

the basic formula to figure out approximately what you will want/need is AH/amp draw=hours run time.

 

The other thing to consider is if you are going lithium you will have a longer run time as they will hold voltage for more of hte battery capacity than a standard battery will.  You'll pay for that added run time and massive weight savings though.  

 

i currently run a newport NK180s and have had it about a year and i run 30ah and it has only burned out when I was intentionally trying to burn it down to see how far it would go.  A little less throttle goes a long ways with battery life and the speed decrease is pretty minimal.

Thank you everybody for the great feedback, I think I'll go for the 55# thrust. as many of you express, its better to have the extra power than miss it. I really hate it when I buy something that falls short of what I require. 

torquedoos are awesome, but it seems that in order to install one on my kayak it needs to be a permanent installation. I like to keep the flexibility to use the pedal drive with out heavy modifications. 

I'm still considering buying bixpy for this reason, they are light and easy to carry/remove. that tech looks very convenient.

 

Battery life is my only concern, I want to repuchase a lithium 50ah battery because of weight. I set my kayak on the roof of my grand cherokee and plant to secure the battery inside the hull. so every pound shaved of weight is welcomed.