Electric motor hp for P-18

[Brian N.]

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

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.

[noelH]

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

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".

[noelH]

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.

[pgandw]

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?

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

[tjspiel]

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.

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.

[tjspiel]

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

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.

[tjspiel]

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

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.

[noelH]

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. 

[Grambo the Gray]

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.

[pgandw]

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

[Brian S]

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?

[Straander]

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.

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!

[Straander]

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?

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.

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