electric trolling motor question

[Raider Ronnie]

Anyone using one either salt or fresh water with battery knowledge ?
Wondering as to battery suggestions.
I assume deep cycle but battery size (group 24, 27, 31, 8d)
My main question is (depending on which battery) how much usage/running time I should expect with a 3hp motor on a 12ft aluminum ?
My son Matty & I went out on one of our lakes in Wrentham last evening.
Used the gas outboard to get out to some spots then the 3hp electric to move around slow and battery went dead 20-30 minutes of use (fully charged the deep cycle the day before but admittedly the battery is a few years old)
Thanks in advance.

Also.
Matty caught a handful of large mouth and I just sat back and smiled.
Nice change of pace from the salt !

[Rockfish9]

Originally Posted by Raider Ronnie

Anyone using one either salt or fresh water with battery knowledge ?
Wondering as to battery suggestions.
I assume deep cycle but battery size (group 24, 27, 31, 8d)
My main question is (depending on which battery) how much usage/running time I should expect with a 3hp motor on a 12ft aluminum ?
My son Matty & I went out on one of our lakes in Wrentham last evening.
Used the gas outboard to get out to some spots then the 3hp electric to move around slow and battery went dead 20-30 minutes of use (fully charged the deep cycle the day before but admittedly the battery is a few years old)
Thanks in advance.

Also.
Matty caught a handful of large mouth and I just sat back and smiled.
Nice change of pace from the salt !

use the biggest battery you feel like lugging... my electric gets more use than my outboard... I normally get 10-12 hours from a group 31 on a Motor guide 55lb thrust pushing a 2200 lb boat... I use an on board smart charger and plug in every night.. I tend to change batteries every 3 years weather they need it or not..

[BigBo]

Ronnie, most electric motors are rated in lbs of thrust instead of hp. If possible, try to determine the amperage required at full throttle. For example, I have a 55lb thrust motor that draws @5 amps at low and 40-45 amps at full throttle. So now take a look at your battery and instead of looking at the group number, look at the AH (amp/hour) rating.
So if I have a battery that is rated for 45AH, that battery will only last one hour with my motor at full throttle. The trade off is that the higher the rating, the heavier the battery becomes (more lead plates) and as you probably already know, the price goes up.
The other problem is that lead cell AGM batteries, while a good bang for the buck, do not drain linearly. They get to a certain level and they go dead very quickly. And can only be recharged a given number of cycles.
There are other alternatives, but they get very expensive and when you're talking about getting out on the pond with the boy in a 12' tinnie, are hard to justify.
So, just look into a higher AH rating in a lead cell and go have fun with the boy.

[Raider Ronnie]

Originally Posted by BigBo

Ronnie, most electric motors are rated in lbs of thrust instead of hp. If possible, try to determine the amperage required at full throttle. For example, I have a 55lb thrust motor that draws @5 amps at low and 40-45 amps at full throttle. So now take a look at your battery and instead of looking at the group number, look at the AH (amp/hour) rating.
So if I have a battery that is rated for 45AH, that battery will only last one hour with my motor at full throttle. The trade off is that the higher the rating, the heavier the battery becomes (more lead plates) and as you probably already know, the price goes up.
The other problem is that lead cell AGM batteries, while a good bang for the buck, do not drain linearly. They get to a certain level and they go dead very quickly. And can only be recharged a given number of cycles.
There are other alternatives, but they get very expensive and when you're talking about getting out on the pond with the boy in a 12' tinnie, are hard to justify.
So, just look into a higher AH rating in a lead cell and go have fun with the boy.

What I have is a Mincota 3 hp
3hp is actually the model name.
To the best of my knowledge it's a 55 lb thrust motor.
Posted from my iPhone/Mobile device

[nautibuoys]

I have one of those 3 HP electric motors and per MK, they were top of the line at their time. It's roughly a 50lb thrust motor. They also said the HP stood for High Power, not horsepower. However, it has the digital maximizer in it and with my Group 27 deep cycle battery I can push my 15' square back canoe with 2 big guys around all day and only be down less than half a battery.
Posted from my iPhone/Mobile device

[Raider Ronnie]

Originally Posted by nautibuoys

I have one of those 3 HP electric motors and per MK, they were top of the line at their time. It's roughly a 50lb thrust motor. They also said the HP stood for High Power, not horsepower. However, it has the digital maximizer in it and with my Group 27 deep cycle battery I can push my 15' square back canoe with 2 big guys around all day and only be down less than half a battery.
Posted from my iPhone/Mobile device

Thanks.
That's the info I was looking for.
Going to buy a new group 31 deep cycle.
Posted from my iPhone/Mobile device