Just bought a P-18 and I would like to put and electric trolling motor on it to move around and exit the dock area. Based on my research a 2 hp should be good enough. Has anyone ever tried this approach?
I have used a Minn Kota 50 lb thrust with a 42 inch shaft on my P165 and it moved it very well. It weights in at 750 lbs plus misc onboard, I guess 1000 lbs total. Minn Kota claims you will need 2 lbs thrust per 100 lbs of weight. I only had about 1/4 mile from the dock to open water and it took about 20 minutes each way. The 100 amp hour marine battery was supposed to last 1.5 hours with the motor on the highest setting. I also used a 20 watt solar panel to maintain the battery. It makes a pretty inexpensive package that works quite well compared to the $3000 Torquetta"s
{spelling}.
Rich
The Epropulsion Spirit 1.0+ cost me $2559 before sales tax this July. Epropulsion rates the Spirit as equivalent to a 3hp gas outboard, and I agree with them, having previous had a 5hp gas outboard. Spirit has 1hr 15 min at full throttle which has little use on my boat. On my 19ft Mariner I get 4.5kts at half throttle (checked with my GPS) with 2.5hrs run time. Normally use 300-400 watts for motoring at 3.5-4.0 kts, giving a range of 12+nm and 3.5-4hrs run time. Perfect fit for my Mariner, all the power I need with a reasonable range. Does cost though, more than half the value of the boat.
But the motor got me out of the doghouse with the wife, who was complaining I never used the sailboat. She was right, I had a hard-learned anxiety about whether or not that gas outboard would start when I wanted/needed it to. I started out with range anxiety with the Spirit, but a 3 day cruise from Niantic, CT to Mystic CT and back proved it had enough power to handle the 3-4 knot tidal currents against me at the railroad bridge on the Niantic River, and still had enough range to power 6 miles in the Niantic and Mystic Rivers, with 50% battery left at the end of each day. Similar results here in NC motoring 6.2 miles from the launch ramp to home dock in 1hr 29 min. Recharged battery each evening.
Fred W
Stuart Mariner 19 #4133 Sweet P
Yeopim Creek, Albemarle Sound, NC
Quote from: Grambo the Gray on Sep 04, 2023, 03:21 PMJust bought a P-18 and I would like to put and electric trolling motor on it to move around and exit the dock area. Based on my research a 2 hp should be good enough. Has anyone ever tried this approach?
Just based on what I've heard other people say, a 2 hp outboard should be enough to get a P18 up to hull speed.
But trolling motors aren't designed for speed and they are usually sized in terms of pounds of thrust rather than horsepower. They are meant for moving boats slowly. So you'd need a fairly large trolling motor to get the equivalent of 2 HP and you're probably need a 36 volt system or 3 twelve volt batteries.
But if all you need it for is moving around and exiting a dock area, you don't need to move at hull speed and a trolling motor will likely serve you well. They're very reliable and require little maintenance. If your boat is in a slip or on a mooring, install a solar panel to keep the battery charged and life will be easy. :)
My boat is on an electric only lake. Sailboats are limited to 22 ft in size and everyone (myself included) uses trolling motors if they have motors at all.
But we do not need to worry about tides or currents. That can make a big difference.
I've had a 40 lb thrust Minn Kota on my P-18 for about 3 seasons and I'd describe it as adequate. When I was trying to tow another boat against a heavy wind a few weeks ago I could barely make any headway with it.
Even though those were unusual circumstances, I still decided it was time to upgrade to a 50 lb thrust motor. 55 lb is about the limit for a 12 volt system.
If you're going to be motoring long distances out in open water, I'd not recommend a trolling motor. But for what I use a motor for and for what you're describing, they work really well.
You start them by twisting the tiller handle. Twist the other way and you're in reverse. No spinning the motor around. No reaching back for a lever. No annoying engine drone grinding on your nerves or making conversation difficult.
Quote from: pgandw on Sep 04, 2023, 07:44 PMThe Epropulsion Spirit 1.0+ cost me $2559 before sales tax this July. Epropulsion rates the Spirit as equivalent to a 3hp gas outboard, and I agree with them, having previous had a 5hp gas outboard. Spirit has 1hr 15 min at full throttle which has little use on my boat. On my 19ft Mariner I get 4.5kts at half throttle (checked with my GPS) with 2.5hrs run time. Normally use 300-400 watts for motoring at 3.5-4.0 kts, giving a range of 12+nm and 3.5-4hrs run time. Perfect fit for my Mariner, all the power I need with a reasonable range. Does cost though, more than half the value of the boat.
But the motor got me out of the doghouse with the wife, who was complaining I never used the sailboat. She was right, I had a hard-learned anxiety about whether or not that gas outboard would start when I wanted/needed it to. I started out with range anxiety with the Spirit, but a 3 day cruise from Niantic, CT to Mystic CT and back proved it had enough power to handle the 3-4 knot tidal currents against me at the railroad bridge on the Niantic River, and still had enough range to power 6 miles in the Niantic and Mystic Rivers, with 50% battery left at the end of each day. Similar results here in NC motoring 6.2 miles from the launch ramp to home dock in 1hr 29 min. Recharged battery each evening.
Fred W
Stuart Mariner 19 #4133 Sweet P
Yeopim Creek, Albemarle Sound, NC
If I had more demanding needs of an outboard (and had more money), I'd be tempted by the ePropulsion. I've heard those can be re-charged (at least a little) by the boat spinning the prop as you move through the water. Is that true?
I agree with you on the fussiness of gas motors. They can be very reliable if well maintained and you use them often enough to know their individual quirks, - which they all seem to have or develop over time. :)
This past Spring I went sailing in Croatia with a large group of people on 4 boats. One decision we had to make was whether or not we wanted to pay a little extra money to have outboards on our tenders. Even though we'd never going more than a short distance in them, I was outvoted and we all got them.
My experience with those abused outboards on charter boat tenders has not been good and Croatia was no exception. 3 of the 4 little Suzukis experienced serious problems starting and two were practically worthless. Not only did it take forever to get them started and they'd stall within 5 minutes. Not worth the hassle.
I think Tom gave you some great info, and agree that a 50-55lb thrust 12 volt system might be a great choice. Gas engines are great work horses, but require feeding and care.
Quote from: tjspiel on Sep 04, 2023, 09:14 PMI've heard those can be re-charged (at least a little) by the boat spinning the prop as you move through the water. Is that true?
The Spirit 1.0 Plus EVO does have hydrogeneration, the 1.0 Plus doesn't. It starts at 4 kts (50W), and isn't really significant until around 6 kts (140W). At 10 kts (360W), the hydrogeneration cuts off to protect the system. So, if you can sail for extended stretches at 6+ kts it could be useful, if the drag from the system is acceptable.
The British dealer Nestaway does a good job comparing the Torqeedo 1103 and Spirit models. They sell both. Scroll down for their thoughts on the EVO hydrogeneration.
https://nestawayboats.com/shop/epropulsion-spirit-plus-1kw-electric-outboard/
Hello Grambo. I recently upgraded my P165 to a Newport Vessels 86lb thrust trolling motor ($250) and a 100ah 24v LiFPO4 battery ($630). After a outing this spring, I had decided that my 12V, 62lb thrust motor just wasnt cutting it. The new system is working out for me well so far, can get close to 4knots in calm flat water, and can still make a little headway against wind and significant waves as I found out last sunday. Still, not what id want to count on for main propulsion if I was out in the ocean though.
One annoyance with these trolling motors is that they're made to push a heavy load slowly, so going overboard on lbs-thrust gives only minimal speed increases in lighter, efficient hull designs like these sailboats. I measured the current draw when at speed and it was only about 2/3 of what the motors max rated current draw was listed at, implying I was leaving a lot of power on the table. I wish the companies would offer higher-pitch propellers for them for usages like ours.
Quote from: Grambo the Gray on Sep 04, 2023, 03:21 PMJust bought a P-18 and I would like to put and electric trolling motor on it to move around and exit the dock area. Based on my research a 2 hp should be good enough. Has anyone ever tried this approach?
Torqeedo, EPropulsion, Temo.... Plus probably more choices for electric boat motors. Torqueedo Travel user for the past 6 seasons. Overkill for my needs. Just to get in and out of the marina. Temo has an interesting 450 watt motor. Looks like a stick with a prop at the end. Transom quick attach mounting plate turns it into a more "proper" motor. Light at ~5kg total mass. Not a boatload of thrust. In one video review it was able to push a dinghy at ~2kts is gentle choppy seas. They have a model that caught my interest that is in the same class as the Travel and Spirit. The features I liked about it was a height adjustable shaft. No need to choose between a long or short shaft. The motor in the kicked up position can be rotated 180 degrees for easy removal from within the cockpit. Even with the battery and tiller removed from the Travel it is a pita to remove in anything but calm seas.
A seasonal resident trailer sailor just purchased a EPropulsion electric. His boat has a motor well. Originally was looking at the Torqeedo Cruise, but the EPro Spirit meets his needs. Plenty of power to move his +20 footer in and out of the marina. He was using a MKota trolling motor, but got tired of dealing with a lead acid battery and the very limited capacity.
In addition to news of new developments in marine electric propulsion in general, Plugboats puts out some guides that might be useful, especially the Less than 5kW and Trolling Motor versions.
https://plugboats.com/category/plugboats-guides/
They don't seem to include the Temo. In the Trolling Motor guide they do mention that they didn't include bow-mounted motors, but rather focused on transom-mounted ones used primarily for propulsion. The long-tail Temo design might have fallen in the "others" category. Interesting design!
Quote from: noelH on Sep 12, 2023, 11:52 AMTemo has an interesting 450 watt motor. Looks like a stick with a prop at the end. Transom quick attach mounting plate turns it into a more "proper" motor. Light at ~5kg total mass. Not a boatload of thrust. In one video review it was able to push a dinghy at ~2kts is gentle choppy seas. They have a model that caught my interest that is in the same class as the Travel and Spirit. The features I liked about it was a height adjustable shaft. No need to choose between a long or short shaft. The motor in the kicked up position can be rotated 180 degrees for easy removal from within the cockpit. Even with the battery and tiller removed from the Travel it is a pita to remove in anything but calm seas.
Temo is interesting but not sure it's practical for a sailboat. One thing you might want a motor for is to keep you headed into the wind as you raise/lower sails. The Temo is trigger operated, - once you let go to move forward, it stops.
The Temo 1000 would be more suitable for those of us who are motor dependent to hoist and lower sail. On light wind days I usually just more or less point the bow into the wind and rapidly as possible hoist the sail. Only dealing with ~80 sq foot main. Easily raised from the cockpit.
Figure if Lin and Larry Pardey sailed couple time around the world without a motor there must be something I haven't figured out in hoisting and dropping a sail without a motor in stronger winds and choppy seas. Did have to drop the sail once in strong winds without motor aid. No option. Straight-line wind of +50kts coming my way. Just turned Vela hard into the wind after dropping the jib and quickly dropped the main. Got the last sail tie on and just hooked in before a barepole knockdown.
Torqeedo has a new Travel model out the 9??. Little less money the Travel 1103C. Same battery. I think it is marketed as equivalent to 2.5hp ICE.
Switching the battery of the Temo 1000 looks to be significantly easier than either the Travel or Spirit. Especially under lumpy conditions. Those waterproof connections on the Travel and Spirit are to be too easy to cross thread. I know on the Travel careful threading even on land is required.
Temo tiller doesn't give you the data that the Travel and Spirit does. Looks like there is an indicator for low capacity, but no SOG, watts, estimate range....But I like how the tiller folds into the shaft. I find the Travel's tiller to be at times in the way. Vela has only a 5ft cockpit. Really only 4 functional linear feet with the rudder tiller and the motor tiller taking up space. Space under the rudder tiller is where I stick my cooler. So not really wasted space.
Torqeedo battery life seems to be as advertised. Better be considering the $$$$s. My rarely used backup battery is 6 seasons old. Basically like new capacity. Have yet to notice any diminished capacity on the primary battery based on range relative to SOG. Eventually probably just replace the motor and shaft with a1103C unit if sold as a stand alone. One thing to consider when purchasing a motor. The back compatibility of older models. Checked with Torqeedo. They emailed me that the 1003 tiller unit and battery can be used on a 1103. The new 9?? uses the same batteries. Not sure about the tiller unit.
One thing that makes me skittish about buying a Torqeedo or ePropulsion is the lifespan. I don't think you can count on a battery lasting more than 10 years (even if unused) or that 10 years from now you'll be able to even get a battery for a 10 year old model. Can you even buy a battery for an old Torqeedo 503 from 2016 for example?
Personally I like to purchase big ticket items on the used market and in the case of these electrics they'd have a limited lifespan left.
So I'll probably be sticking with trolling motors until there's a 3rd party replacement option for electric outboard batteries or they otherwise get much less expensive.
Or what may happen is that eventually I'll get to a point where I've only got 10 or so years left of sailing in me so what the hell. :)
A cable to use an external battery for both the Epropulsion Spirit and Spirit EVO is available. Needs a 48V battery - drop-in LiFePO 48V batteries are now also available. But 25AH at 48V (slightly smaller than the stock battery) still isn't cheap.
The Spirit battery is rated at 80% after 500 charge/discharge cycles. Using the battery 50 weeks per year, you would reach 80% capacity in 10 years. And the battery floats. Your gas outboard is going to need a lot more maintenance than battery replacement in 10 years.
Still your choice. If a trolling motor suffices, then don't go bigger.
Fred W
Don't get me wrong, I really like the idea of an electric motor and would prefer it to gas. But a lithium battery degrades with time as well as charge cycles. It may be next to worthless in 10 years no matter how little you use it. And at that point, is the motor even worth keeping or are you better off getting a new one?
A small gas engine can be fussy for sure but if you take care of them they can last for decades without much in the way of maintenance costs. I've had a snow blower for a long, long time and once I learned not put ethanol in it I've really had no trouble with it.
But eventually gas motors will be a thing of the past. There's little doubt in my mind of that.
There's a trip planned to Lake Pepin (wide spot in the Mississippi) for the second week of October. And I was looking for outboards for that since a trolling motor won't cut it. Would have probably bought a used gas engine for it because I just can't justify the cost of an electric. But as it turns out I'm going to be out of state on the same weekend so I don't need to worry about it, - at least until next year.
Quote from: tjspiel on Sep 15, 2023, 10:14 AMDon't get me wrong, I really like the idea of an electric motor and would prefer it to gas. But a lithium battery degrades with time as well as charge cycles. It may be next to worthless in 10 years
We Looked at the new Subaru all electric vehicle - very nice, but the Salesman said the batteries will last 10 years then need replacement. We tend to keep our cars a very long time and could not justify the initial price tag, and then down the road thousands more.
Quote from: Brian N. on Sep 15, 2023, 10:49 AMQuote from: tjspiel on Sep 15, 2023, 10:14 AMDon't get me wrong, I really like the idea of an electric motor and would prefer it to gas. But a lithium battery degrades with time as well as charge cycles. It may be next to worthless in 10 years
We Looked at the new Subaru all electric vehicle - very nice, but the Salesman said the batteries will last 10 years then need replacement. We tend to keep our cars a very long time and could not justify the initial price tag, and then down the road thousands more.
The discontinued 503 uses the same battery as my backup 500 watt for the 1003. Which also is the same for the 1103, 903, and 603. Same for the tiller control unit. Right now it's one reason why I will probably stick with Torqeedo v. Temo or EPropulsion.
Regarding ICE. Have an old Jonsered chainsaw that is no longer supported by the manufacture in terms of spare parts. Good local chainsaw shop that stocks hopefully compatible parts. But getting sketchy. So last year purchased a backup chainsaw. Went electric. EGO Power+18". Bit underpowered vs. the Jonsered, but convenient and no fuss. Just hope they have follow Torqeedo regarding back compatible battery.
As long as parts are available anything can be maintained for a long time. Unfortunately in our throw away world. Becoming more difficult to source parts. Back in the late 70's I use to work for a bicycle store. Parts department and sales/assembly and very occasionally the repair shop. For any component we had the individual parts to rebuild. Now a days you replace the whole part. Or "upgrade".
The Torqeedo Travel series is not maintenance free. Manual notes every 700 hrs or 5 years the motor seals should be replaced. But relative to an ICE. End of season maintenance is hang it on the rack and charge up the battery.
Weird thing about the Torqeedo battery is they recommend charging to full for long term storage vs. most other Li based batteries sitting at a slight discharged storage level. My EGO battery has some sort of BMS that self discharges to it's ideal storage level if not used for a period of time. The Torqeedo is LiNMC chemistry and so far for longterm storage (6 months) maintains 100% capacity if stored under cooler conditions.
I think it was a YTube video at a boat expo and ePropulsion or Temo. One tank the electric motor. Other tank a new mode 4 stroke ICE. Both running for a set period of time. The ICE motor tank was foul vs. clear EPropulsion tank. Maybe a reason why some lakes ban ICE in addition to the noise? The stench and film at the Marina ramp some days is disgusting. But L. Superior is big BS excuse. Just like Ashland WI dumping storm and raw sewage overflow into the Bay.
QuoteDon't get me wrong, I really like the idea of an electric motor and would prefer it to gas. But a lithium battery degrades with time as well as charge cycles. It may be next to worthless in 10 years no matter how little you use it. And at that point, is the motor even worth keeping or are you better off getting a new one?
Battleborn advertises their LiFePO batteries as having lifetimes over 10 years, as do some other LiFePO battery sellers. But the Epropulsion and Torqueedo batteries are not LiFePO, they are a different lithium chemistry. Nobody is advertising a lifetime.
In my case, the electric outboard was necessary to fend off DW pressure to get rid of the boat. She correctly pointed out that because I couldn't reliably start my used 5hp Honda, I wasn't using the sailboat enough. My ability to buy reliable used outboards has been about 50:50. With new outboards, I've never had a problem. When I looked at the cost difference of new gas vs new electric, the electric advantages sucked me in. The only advantage of a new gas outboard over my Spirit is the tripling of the range available IF I use an external 3 gal tank. I decided to live with the 12+ nm range of the Spirit, and gain the quiet, the extra cockpit space, and getting rid of motor starting anxiety.
The great thing is that today we have the choice, depending on our needs/desires.
Fred W
Quote from: noelH on Sep 15, 2023, 02:35 PMI think it was a YTube video at a boat expo and ePropulsion or Temo. One tank the electric motor. Other tank a new mode 4 stroke ICE. Both running for a set period of time. The ICE motor tank was foul vs. clear EPropulsion tank. Maybe a reason why some lakes ban ICE in addition to the noise? The stench and film at the Marina ramp some days is disgusting. But L. Superior is big BS excuse. Just like Ashland WI dumping storm and raw sewage overflow into the Bay.
A couple of years ago we chartered a boat out of Pikes Bay Marina on Lake Superior. Engine quit on the last day less than halfway back to the marina. Tracked the problem down to the fuel line which had hardened and split at the nipple. We cut the end off, stuck it back on and it lasted for a bit before starting to split again.
For the next half hour we (me to be exact) was literally holding the fuel line on until it was hopeless. Fuel was squirting all over, - which ended up in the bilge of course.
Fortunately the wind had come back up so we were able to sail the rest of the way back to the marina, but we had to get towed into the marina itself.
They were freaked out about the fuel in the bilge because they naturally don't want that pumped into the lake. They have to adhere to some pretty strict practices there I guess. So the owner was going to have to get the bilge cleaned up. It's not like there was gallons of fuel in there, - maybe a cup at the most, but I can see where they are coming from.
Quote from: Brian N. on Sep 15, 2023, 10:49 AMQuote from: tjspiel on Sep 15, 2023, 10:14 AMDon't get me wrong, I really like the idea of an electric motor and would prefer it to gas. But a lithium battery degrades with time as well as charge cycles. It may be next to worthless in 10 years
We Looked at the new Subaru all electric vehicle - very nice, but the Salesman said the batteries will last 10 years then need replacement. We tend to keep our cars a very long time and could not justify the initial price tag, and then down the road thousands more.
We have an 11 year old Chevy Volt which is turning the corner on 150,000 miles. We keep our cars a long time too but if it lasts another couple of years, that's good enough in my book. It is a bit of crapshoot because I know the batteries have failed on some Volts at about 10 or 11 years, but I don't if that's typical or not.
What is different about EVs is that the batteries have active thermal management systems on them. They are both heated and cooled as necessary to extend their lives. I doubt the battery packs on the compact outboards from either Torqeedo or ePropulsion have that although it sounds like the larger inboards and outboards from Torqeedo might.
After driving the Volt for going on 6 years now I'm pretty sold on EVs and our next car will likely be a fully electric, even if the Volt died tomorrow. We typically buy cars that are a few years old but in the case of EVs I might actually consider leasing. If turns out that EV batteries can hold up pretty consistently for 12 to 15 years, I'll be much more comfortable about buying used.
Quote from: pgandw on Sep 15, 2023, 03:01 PMIn my case, the electric outboard was necessary to fend off DW pressure to get rid of the boat. She correctly pointed out that because I couldn't reliably start my used 5hp Honda, I wasn't using the sailboat enough. My ability to buy reliable used outboards has been about 50:50. With new outboards, I've never had a problem. When I looked at the cost difference of new gas vs new electric, the electric advantages sucked me in. The only advantage of a new gas outboard over my Spirit is the tripling of the range available IF I use an external 3 gal tank. I decided to live with the 12+ nm range of the Spirit, and gain the quiet, the extra cockpit space, and getting rid of motor starting anxiety.
The great thing is that today we have the choice, depending on our needs/desires.
Fred W
I get that. The problem for me is that money that I spend on the boat comes out of my mad money and I have only a rare need for a real outboard of any kind. I just can't justify the cost of an electric one though that would be my preference.
At least on the Torqeedo Travel series. No thermal battery maintenance management. Just a monitor that shuts the motor off if battery temp exceeds a certain temperature. Most days sailing the cooler temperatures shouldn't be too much of an issue. IR increases with lower temperature resulting in decreased capacity.
Electric outboards are expensive and the price increases are widening the gap between them and ICE. Honda looks to have kept their prices on the 2.3 relatively stable vs. the electrics. EPropulsion looks to be the better value. But still a good 50% upfront higher costs. The Temo 1000 and Travel 1103C are real expensive.
Thank you all for the great advice. I am seriously thinking about the epropulsion evo for the hydro generation feature. Currently I am prepping to do some driveway sailing so that I can effectively set up the boat when the time comes for a real sail. My new project is to come up with some type of aid to lift the mast. There are many ideas on ytube and I am trying to decide which one would work best. As I learn what I don't know I will be posting more questions thanks in advance.
Just a note - the hydro-generation on the Evo doesn't kick in until 4 knots. And takes 5 knots to get up to about 50 watts of generated power. In my use case, the little power generated at typical speeds on my 19ft Mariner isn't worth dragging the prop in the water.
Fred W
I have always wondered about the propeller shape of trolling motors, and why they are shaped as they are, and what the ramifications of that shape are. I've often thought that since they are marketed to fishermen, they are shaped to move boats slowly and shed weeds. (Haha, having got stuck in weeds on a lee shore in my daggerboard 10' sailing skiff just yesterday! Couldn't pull up the daggerboard without blowing to shore, and the kick up rudder kept, well, kicking up. Kinda sorta sailed out/pushed my way out with an oar.) Looking at propellers of other electric motors such as the Electric Oar and eProp and Torqeedo, the propellers are shaped much differently than trolling motors. Not being any kind of expert on fluid dynamics or propeller design, it's interesting to look at these differences. Given the different use-case scenario of "electric outboards" vs. trolling motors, I expect these "outboard" props to be more optimized for thrust per watt. Indeed, with the longer, higher aspect blade shapes, I think this tracks vs. the short, stubby, curved blades of trolling motors.
Which leads me to a slight YouTube rabbit hole I went down a bit ago, where I found a couple of fishermen replacing the trolling motor propellers with larger diameter, much higher aspect ratio model airplane propellers. Then the guys would compare mainly speed. I didn't find their testing methodology particularly impressive, or their data points or data collection all that rigorous.
I expect one would need to choose a propeller in such a way that it balances thrust/watt and speed/watt to maximize range. But looking at the longer, higher aspect ratio props of model airplanes, you see the same blade shape on the Electric Oar, which is basically a trolling motor, and then the props of Torqeedo and eProp, which are higher aspect but have tips swept to a rounder shape, again I assume to tolerate lower tip pressures due to higher density water than air. I remember discussions by Torqeedo when they were introducing their motors years ago discussing optimized propeller blade shape for electric, and I think the original blade shapes have changed to what they are now (which look more like gas outboard props) but don't hold my memory to that.
Also still unsure about the assertion by some people that lithium technology batteries should not be used for trolling motors in favor of lead acid technology batteries. I see quite a few YouTubers posting videos using LiFePO4 on trolling motors. The main argument I see against lithium batteries is that they produce a higher voltage for sustained periods of time without a voltage drop off, which could be hard for the trolling motor speed controller to handle. I imagine producing higher heat leading to early failure?
This is a really cool guide. There are many brands there I haven't heard of before.
Good to see some Trolling motors are being made brushless. No idea why Minn-Kota and newport use brushed motors when you can get brushless in everything down to electronics cooling fans.
Quote from: Bruce Mason on Sep 12, 2023, 04:58 PMIn addition to news of new developments in marine electric propulsion in general, Plugboats puts out some guides that might be useful, especially the Less than 5kW and Trolling Motor versions.
https://plugboats.com/category/plugboats-guides/
They don't seem to include the Temo. In the Trolling Motor guide they do mention that they didn't include bow-mounted motors, but rather focused on transom-mounted ones used primarily for propulsion. The long-tail Temo design might have fallen in the "others" category. Interesting design!
Quote from: Brian S on Oct 30, 2023, 10:01 AMI have always wondered about the propeller shape of trolling motors, and why they are shaped as they are, and what the ramifications of that shape are. I've often thought that since they are marketed to fishermen, they are shaped to move boats slowly and shed weeds. (Haha, having got stuck in weeds on a lee shore in my daggerboard 10' sailing skiff just yesterday! Couldn't pull up the daggerboard without blowing to shore, and the kick up rudder kept, well, kicking up. Kinda sorta sailed out/pushed my way out with an oar.) Looking at propellers of other electric motors such as the Electric Oar and eProp and Torqeedo, the propellers are shaped much differently than trolling motors. Not being any kind of expert on fluid dynamics or propeller design, it's interesting to look at these differences. Given the different use-case scenario of "electric outboards" vs. trolling motors, I expect these "outboard" props to be more optimized for thrust per watt. Indeed, with the longer, higher aspect blade shapes, I think this tracks vs. the short, stubby, curved blades of trolling motors.
Which leads me to a slight YouTube rabbit hole I went down a bit ago, where I found a couple of fishermen replacing the trolling motor propellers with larger diameter, much higher aspect ratio model airplane propellers. Then the guys would compare mainly speed. I didn't find their testing methodology particularly impressive, or their data points or data collection all that rigorous.
I expect one would need to choose a propeller in such a way that it balances thrust/watt and speed/watt to maximize range. But looking at the longer, higher aspect ratio props of model airplanes, you see the same blade shape on the Electric Oar, which is basically a trolling motor, and then the props of Torqeedo and eProp, which are higher aspect but have tips swept to a rounder shape, again I assume to tolerate lower tip pressures due to higher density water than air. I remember discussions by Torqeedo when they were introducing their motors years ago discussing optimized propeller blade shape for electric, and I think the original blade shapes have changed to what they are now (which look more like gas outboard props) but don't hold my memory to that.
Also still unsure about the assertion by some people that lithium technology batteries should not be used for trolling motors in favor of lead acid technology batteries. I see quite a few YouTubers posting videos using LiFePO4 on trolling motors. The main argument I see against lithium batteries is that they produce a higher voltage for sustained periods of time without a voltage drop off, which could be hard for the trolling motor speed controller to handle. I imagine producing higher heat leading to early failure?
I have not ever heard about not using Lithium batteries for trolling motors before. Indeed, almost every Lithium battery maker's product pages list Trolling motors as one of the primary applications. I'm not too concerned about excess heat since I've measured my trolling motor's power draw at about 30 amps at cruise, well below the 48A that is listed as the motor's peak draw. Trolling motors are built to push a large mass slowly and since I am speccing in a motor well in excess of whats recommended for my boat's size to get that extra speed, I imagine I am leaving a lot of extra power on the table when I use it.
Indeed I had a conversation with Newport Vessel's support department before asking if they'd consider making a higher angle of attack replacement propeller option for people who's main goal is get the most power out of their motor, but they did not.
Trolling motor and Electric outboard props have always looked to have a similar aspect ratio of blade design to me. At least the 3-bladed trolling motor props.
817UZfKcwXL._AC_SX466_.jpgtorqeedo-spare-propeller-v10-p1100-travel-510x510.jpg