I have always want all the thrust I could get. That being said I run a 24. because I only have room for 3 batteries. If you are sure you will keep the same boat the 12v will work great and with 2 batteries it should run a long time.
I'm just full of questions lately...trying to make some decisions. I have a Tracker PT 165 with a 24V 70lb. Minn Kota Maxxum trolling motor. I want to upgrade to the Terrova. With a boat this small, I don't think I need 70 - 80 lb. thrust but if I go with 55 lb. thrust it puts me down to a 12 volt unit. My batteries are now wired in series to give me 24 volts but only ~ 120 amp hours. If I go with the 12 volt unit, I would re-wire the batteries in parallel which would stay 12 volts but give me ~240 amp hours. Which is better? It would seem to me that more amp hours would be better for battery life and I would still have the power I need at 55 lbs. thrust.
I have always want all the thrust I could get. That being said I run a 24. because I only have room for 3 batteries. If you are sure you will keep the same boat the 12v will work great and with 2 batteries it should run a long time.
I have similar boat with a very old 98 model 55 lb thrust original trolling motor. If I upgrade I would like to go 80lb thrust 24V but I need to revamp by battery storage and figure out how to get a plate on under the floor to hold both batteries.
55 lb on my boat in the wind is not much fun
I have a 175 Tracker and installed a 24 volt 70 lb Powerdrive and it works great,much better then the 12 volt 45 lb motor it came with.
Go with the 24 volt
I have 12 volt 55 hooked to 2 batteries on 17 ft Wareagle. Works great for spider rigging and never had a problem in the wind or longevity. But if you want to long line or pull cranks for a long period of time go with the 80. Less amp hr's is fine in your comparison because the 24 is a more efficient motor than the 12.
Changed out my 12 volt to a 24volt on my new Alumacraft 16.5, mainly because I had a Motorguide XI5 from another boat, would not go back to 12 volt system.
IIRC it's only 10% more to go with the 80lb. That not much more to prevent any regret on a large purchase.
Eric
The thing is the 24 volt motor is more powerful so you spend less time to travel a given distance. So your not on the pedal as much,or your using a lower speed than the less powerful motor. So all things considered the actual power consumed in amp hours probably works out to about the same. If you ran some really definitive test it may be under certain conditions the 12 volt motor on two batteries may have a little longer life or vice versus. It takes so much THRUST to do what you need to do regardless of voltage. I have a dual voltage trolling motor on one of my boats you can switch from 12 to 24 volt. And then you have 5 speeds on each voltage. If I put it on speed 5 on 12 volt I go slower than on speed 5 on 24 volt. So traveling a given distance I am using about the same amp hours I am estimating.
Can you get by with a 55 lb...yes. Will there be times you wish you had the bigger motor...yes.
To me it's all about how tight your budget is or how much spending the extra money will bother you. If it's not a strain or your not going to have buyers remorse about spending the extra money I would definitely buy the bigger.
No matter what we have we generally find a way to adapt our fishing to work. If I did not try to fish in the wind holding position I could always use a troller 40 percent or more smaller.
Now this longline trolling and pulling cranks and stuff...thats a different thing. More thought required on exactly how many hours you need a given thrust for.
Boy that was long wasn't it. Oh well I wasn't doing anything else . I never thought I would type this much. Heck I never thought I would type at all in my life. I took typing in High School just to be around the girls. I kinda only speedy hunt and peck though.
I think I second most of the thoughts here and would recommend you sticking with the 24V system. More power is always better.
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