TheSamba.com :: View topic - Anyone have experience with electric boat motors?

Sat May 29, 2021 8:26 pm

OK I'm not a boat guy, but my elderly father has a small sail boat ( Sunfish??) and needs a battery powered. light weight trolling motor. Is there something with a Ryobi style 24V or better battery pack that attaches directly to the unit ( maybe like a weed-whacker?). He just needs it to scoot back to the ramp.

Sun May 30, 2021 3:00 am

Could replace the weed whacker cutter head with a prop?

Sun May 30, 2021 3:35 am

xoo00oox wrote: What motor did you have and what size boat? I don’t need more than a few hours of use.

We tried the Minnkota on the Cape but we couldn’t make the charging amd storage work for our daily needs to go ashore.

Fundamental problem. The weight you save in the Motor is given back in the battery.

One kg of gas ( about a liter) has 50 MJ energy.

One kg of Li battery 0.5 MJ energy.

You’ve just swapped weight from motor to energy source.

Minnkota...just buy another $500 battery pack and shore charge them..

Me. $500/ 150 gallons of gas takes me back and forth on the Cape for 75 years

Not to mention when the tide ran the Gut at full ebb, the MK could only just move the boat at about 0.5 knots

Sun May 30, 2021 4:01 am

Manfred58sc wrote: OK I'm not a boat guy, but my elderly father has a small sail boat ( Sunfish??) and needs a battery powered. light weight trolling motor. Is there something with a Ryobi style 24V or better battery pack that attaches directly to the unit ( maybe like a weed-whacker?). He just needs it to scoot back to the ramp.
https://www.torqeedo.com/

Sun May 30, 2021 6:46 am

This is where most of these solutions fail.

Prudent mariner manages fuel with 1/3 out, 1/3 return, 1/3 reserve.

That gives you a 20 minute range of operation from your base.

I’ve had to shoot out into the Bay to recover a Turnabout that got sucked out to sea, with an electric I would be the sailor sitting on my thumb when my green motor gave me the finger.

Sun May 30, 2021 4:32 pm

Thanks Q-dog, that is what I'm looking for.

Mon May 31, 2021 6:52 am

A Sunfish is such a tiny little thing. Barely room for a person. Not sure I have ever seen a motor on one. Probably pay more for the Torqeedo than for the boat. :lol:

Mon May 31, 2021 6:57 am

He used to tough it out w/sails but now he is 75 and wants a bit more control. The money is not really the issue, its about him getting out on the lake while he still can. Sunfish can handle 2 people. I don't like boats , I'll hang at shore till he needs to load on the trailer.

Tue Jun 29, 2021 7:45 am

getting closer...

I made a cutwater for the front

wet sanded and buffed the top and sides..

Tue Jun 29, 2021 7:55 am

thats fricken AWESOME!!! as for the electrick boat motors I have a "long shaft" "Johnson"" wounder troll".....that I tried to sell a few years back...on craigs list & the thirsty nipple...( thrifty nickel).all the calls I got were from old women wanting to trade antiques for it :shock: my wife had to explain it to me :shock: :roll: yes Ive lived a sheltered life at the race track and machine shop... But Im learning!!!( I think)

Tue Jun 29, 2021 8:07 am

Thanks Mark Tucker,

I had to look up what the "wondertroll" was, that is a strange looking motor. That's funny about the older women! I guess a long-shaft Johnson is worth trading their antiques for.

Tue Jul 06, 2021 6:06 am

Almost exactly 5 months after I started building the boat I was able to take it out for a ride.

Tue Jul 06, 2021 7:31 am

That looks great! Nice job! Congratulations! How much battery in it? Does it perform about how you expected?

Tue Jul 06, 2021 7:51 am

Q-Dog wrote: That looks great! Nice job! Congratulations! How much battery in it? Does it perform about how you expected?

Thank you Q, I'm using a 48v 100ah LifePo4 battery that I put together myself from cells I bought on AliExpress. The battery weighs 75lbs.
It does perform about how I expected it, it gets up on plane and will go about 15mph. It feels quick moving that fast in this little boat.
I really like that it is portable, two people can pretty easily carry the boat if the motor and battery are off of it. I think I may be able to put it inside my Vanagon and shut the door. I haven't tried it yet but according to the tape measure it should work.

Tue Jul 06, 2021 8:23 am

WOW! I've been wondering how progress was going on your boat? You did an amazing job, and that motor pushes it along really well! Well done, sir!

Tue Jul 06, 2021 9:07 am

What do you call 10 coats of lovingly applied spar varnish to a beautyful teak and holly look?

...A good start

:D

Lovely!

:lol:

Tue Jul 06, 2021 9:59 am

xoo00oox wrote: Q-Dog wrote: That looks great! Nice job! Congratulations! How much battery in it? Does it perform about how you expected?

Thank you Q, I'm using a 48v 100ah LifePo4 battery that I put together myself from cells I bought on AliExpress. The battery weighs 75lbs.
It does perform about how I expected it, it gets up on plane and will go about 15mph. It feels quick moving that fast in this little boat.
I really like that it is portable, two people can pretty easily carry the boat if the motor and battery are off of it. I think I may be able to put it inside my Vanagon and shut the door. I haven't tried it yet but according to the tape measure it should work.
I am really impressed with these batteries. I've been running 24 volt, 200ah LiFePo4 on a home battery backup (so same capacity) since December, and I just doubled that this week. I still need to build a shelf for the second set to permanently hang all of them on the wall, but the system has been runing great. 400ah at 24 volts, 155 pounds hanging on the wall. Similar usable capacity in lead acid would weigh over 400 pounds and would have to sit on the floor.

I looked at cells on Aliexpress, but I didn't trust a few of the vendors I found and didn't want to wait 2 months for a boat to cross the ocean. I bought cells and BMS from a solar company in Colorado that had them in stock.

Once again, nice job on the boat. =D>

Tue Jul 06, 2021 11:21 am

Q-Dog wrote: xoo00oox wrote: Q-Dog wrote: That looks great! Nice job! Congratulations! How much battery in it? Does it perform about how you expected?

Thank you Q, I'm using a 48v 100ah LifePo4 battery that I put together myself from cells I bought on AliExpress. The battery weighs 75lbs.
It does perform about how I expected it, it gets up on plane and will go about 15mph. It feels quick moving that fast in this little boat.
I really like that it is portable, two people can pretty easily carry the boat if the motor and battery are off of it. I think I may be able to put it inside my Vanagon and shut the door. I haven't tried it yet but according to the tape measure it should work.
I am really impressed with these batteries. I've been running 24 volt, 200ah LiFePo4 on a home battery backup (so same capacity) since December, and I just doubled that this week. I still need to build a shelf for the second set to permanently hang all of them on the wall, but the system has been runing great. 400ah at 24 volts, 155 pounds hanging on the wall. Similar usable capacity in lead acid would weigh over 400 pounds and would have to sit on the floor.

I looked at cells on Aliexpress, but I didn't trust a few of the vendors I found and didn't want to wait 2 months for a boat to cross the ocean. I bought cells and BMS from a solar company in Colorado that had them in stock.

Once again, nice job on the boat. =D>

Thanks! These modern batteries make a huge difference compared to lead-acids. A typical 12v 100ah lead acid weighs about 70lbs so four of them to make 48v 100ah would be 280lbs! This boat would not plane and would only go about 7mph. It took about 3 months for my cells to be shipped to me.

Big Bull Shooter- thanks! It's been a rewarding project, fun to be able put it in the lake and use it after working on it for hundreds of hours.

Abcate- You're right! Takes a lot to keep these wooden boats sparkly! I'm glad it's a small boat.

Tue Jul 06, 2021 6:01 pm

Tue Jul 06, 2021 6:59 pm

andrew you're such a letdown.

i figured you'd have 1.8t'd this thing :D

great work as always. that boat is killer! kid looks pretty happy too!