Electric Dinghy Outboard Motors

[Ken E.]

Is anyone using an electric outboard on their dingy, one equivalent to about a 10 hp gas outboard? Interested in general observations...holding a charge, cost, general operation of it. And charging it while at anchor.

 

[MV Moira]

I was looking at doing so, until I looked at the weight of the batteries.

 

[Mac2]

Just confirming: Do you need to get on a plane? What dinghy/weight are you using?

 

[MV Moira]

Just confirming: Do you need to get on a plane? What dinghy/weight are you using?

Assuming that you're responding to me? I was looking at a 10hp-equivalent Torqeedo engine. There are choices with batteries, but the one I was looking at seems to weigh about 50# each and if I read the spec right, you need two. I was looking at a tip-up (Weaver) davit system, and didn't relish having to wrestle with that weight to unload the batteries from the dink every time I used it. Another davit system would have other trade-offs and come to different conclusions.

Edit: A look at the curent Torqeedo line for what they call their 6.0 Cruise recommends 1 x "48-5000" at roughly 80#.

 

[Ken E.]

For me (OP), it would be an 11' hard dinghy, weight unknown. But I need at least the power of 9.9 hp gas outboard, so the dinghy would plane. And I slso have a Weaver flip-up dinghy system. Loading batteries in and out isn't attractive.

 

[Mac2]

Replying to both above: I went through the same process. Ultimately I opted for two dinghies. A 10 foot inflatable with the epropulsion for 90% of my shore trips and a 15.5 foot aluminum boat for fishing and longer trips. If you do go with an electric outboard, make sure it’s a established brand. I’ve noticed the startups are starting to go out of business.

 

[Mambo42]

I had a Honda 15 Hp outboard, but changed 2 years ago to a Mercury Avator 7.5. This is not exactly 10 Hp, but I also figured I don't need that much power. Water skiing is impossible when you are with just 2 onboard, so why would I want to go fast ?
We need to get to shore 3 or 4 times a day to take the dogs out for a walk and this Mercury does that very well. It is silent, but most of all it is light. My wife can lift this engine up when we reach the shore, she could not do that with the heavy Honda engine (did not have electric raise on the engine).
One of the main decision points was that we don't need gasoline onboard. Fuel stations are usually (in the Med) not near beaches or ports. I would always need a lot of gasoline onboard or I would need to walk a couple of miles with jerrycans.........not really my idea of exercise on a hot day.
This Mercury has a 1 Kwh battery and I can charge that via our solar panels. Normally we can do 3 or 4 days with one battery load, after all, we are not that far away from the shore (max half a mile I would say).
In all I am happy with this outboard, but there are a few items that need further engineering. It is not that the engine fails, but it could have been done more simple, more thought of.
Will I ever change back to a gasoline outboard ?
Absolutely never, for us and electric outboard is the ideal engine.
If I would be 20 years younger and have more people onboard I would like to have an outboard that would make it possible to go water skiing again, but I think I have passed that age. In my mind I can still do it, but my body does not agree with me.

 

[MV Moira]

I envy your outcome and agree with your tradeoffs in general. After all, we're coming to this decision from an 8' hardshell dink with a 2hp outboard! Assuming that your motor has an external battery, what is its weight?

 

[Mambo42]

The engine is basically separated in 3 parts.
The complete engine (battery, engine and mounting) is about 25 kg.
The battery alone is a little less than 10 kg.
The engine without the mounting is about 12 kg
The mounting itself (which stays on the dinghy) is about 3 kg.
My wife can easily tilt the engine with the battery inside, so when she gets to shore she has no problem keeping the prop off the rocks or sea bed.

We were looking as well at Torqeedo and E-propulsion, but for us the deciding factor was the ease with which we could tilt the engine. Both Torqeedo and E-propulsion have a bit of a flimsy battery connection, which we did not like.

 

[DDW]

The "10 HP equivalent" motors are 6KW claimed input. To make that plane, the dinghy and its occupants need to be pretty light. Here is a Youtube video demonstrating this. A little hard to watch because of the delivery style, but he tries both a 9.5' RIB and a 10.5 solid RIB. Planes with one aboard, maybe with two.

I don't see what the issue is with Weaver davits, just strap the batteries down and tilt them. You aren't going to use flooded cells after all.

I've been using an eProp 1KW for 5 years now, it definitely will not plane but for putting around the anchorage or getting to the shore or the pier it is great. So much more convenient than gas, and much quieter. Just bought a new boat which came with a 20 hp outboard dinghy and I promptly sold the dinghy. Using it for a month confirmed that for our use, an electric is better.

 

[Marco Flamingo]

We went with smaller and smaller gas outboards until we finally settled on electric. No need for speed. No need for gas. More important for us is no need for noise. We have found that for viewing wildlife, if you point right at it and go slow, the animal (bear, deer, seal, bird, mink, hippie, etc.) has a hard time registering that you are getting closer. We have easily gotten really close to a grizzly. My safe viewing range is determined by water depth on approach. If I can see the bottom, then it might be able to bound towards me. If it has to resort to swimming, I can 180 and outpace it with my wimpy electric. That's the theory.

Newport makes basic electric "trolling" motors for saltwater in the under-$200 range (Walmart has one that's getting good reviews at under $100). That and a 120Ah lithium battery (another $200) provides an hour of WOT to our viewing destination, 3 hours of poking around, and an hour of WOT on the way back to the boat. WOT is only a little over 4 knots, but we are retired. And 5 hours in the dinghy is as much as my butt can take.

We have several ways of charging back up (plus a second standby LFP battery). Since our electric motor is small, and the LFP battery is <30#, we leave both in the dinghy and raise with the Weaver system. It doubles as our less-than-20-seconds-to-launch life raft.

I'm not burdened with the task of getting a pet ashore to ****, but I assume electric would do the job. Emergency defecations is reason #13 as to why we don't have pets aboard. Seems an odd factor for making a dinghy power decision.

 

[DDW]

We have easily gotten really close to a grizzly. My safe viewing range is determined by water depth on approach. If I can see the bottom, then it might be able to bound towards me. If it has to resort to swimming, I can 180 and outpace it with my wimpy electric. That's the theory.

I spent an afternoon watching a grizzly and her three cubs running down salmon trapped by the tide in a shallow lagoon. Probably 2 feet of water. With the 20 HP gas *maybe* I could outrun the grizz. With the 1KW electric? Not a chance in Hell. They are amazingly fast.

 

[Bmarler]

I’m using a torqeedo, but a small one. It pushes the dink at 5 knots or so. I’d never go back to gas, the electric is so easy to live with. I sold my rendova with a 40 hp and never looked back. The battery lives on top of the thing and comes off in seconds to hand to my wife. It’s easy to stow as well. Does about 95% of what you want a dink to do, just isnt good for the long excursions I did with the rendova. I can live with that. No maintenance either, charges off the inverter.

 

[whistlerxc]

I have an E-propulsion electric- smaller one on an 8 foot hard dingy. I would not go back to gas, but I understand that my need for dingy power is not what the OP is after and besides, others have already explained their philosophy which is similar to mine. I just wanted to add that since the battery comes off the leg, by separating the two when loading and unloading, the individual weights are both less than a complete gas motor so I have found my electric motor actually easier to move around.

 

[Marco Flamingo]

They are amazingly fast.

There is a Youtube video of a grizzly chasing down a bull elk. That's why we stay in deep water. Saw one swimming across the Yukon river and we got quite close. They swim slow. Not that our electric is particularly fast, but the plan is for a head start.

 

[DDW]

The do swim slowly, I could probably outrun one swimming with my electric. But in shallow water they run, they don't swim.

I've considered a 6KW electric on a light dinghy for those few situations when I want to go more than a mile or two. If you limit the run time, you can keep the weight of the engine package to about 110 - 120 lbs. That is a substantial increase over a 1KW motor at about 45 lbs including battery. So beaching and shipping the dinghy become that much harder.

The motor is about 65 lbs and the battery is whatever you want it to be. You can have a couple of batteries and only put in the second one when you are embarking on an expedition somewhere. Since you can run it as slowly as you like, something like a 1KWH battery would give you 10 minutes of 12 knot operation and 2 hours at 4 knots, would not weigh much. They tend to be 48V or higher though, so the battery choices in small sizes are limited.

 

[whistlerxc]

Just a quick note, some electric outboards use only their proprietary batteries so you can only use their batteries to extend the range without a re-charge and only in the sizes they sell. This might make a difference or might not- but with new technologies- (lighter batteries with more power) that specific battery companies are putting out, it is nice to be able to add additional power from another source.

 

[READY]

@Marco Flamingo I suggest you invest in a zoom lens and/or binoculars. I would hate for your dinghy motor battery run out during your dinghy race with that bear

 

[Takoradi]

Is anyone using an electric outboard on their dingy, one equivalent to about a 10 hp gas outboard? Interested in general observations...holding a charge, cost, general operation of it. And charging it while at anchor.

View attachment 169465We use our dinghy for short runs in calm water but a small 28lb trolling motor and a 100ah battery (<24lbs) move us along just fine. Couldn’t cost justify the higher performing heavier Torqueedos and their kin for how we use it. Added benefit is my wife is comfortable driving it.

Is anyone using an electric outboard on their dingy, one equivalent to about a 10 hp gas outboard? Interested in general observations...holding a charge, cost, general operation of it. And charging it while at anchor.

 

[oak_box]

Below are some observations I made while playing with several electric motors on my West Marine RIB 310 (10'2" long, 5' wide, 114 pounds). Much of the data collected below was with the RIB and two adults, in calm water (in our protected marina area).

SUMMARY:
Motor: Voltage: Max Speed: Max Power: Cost:
Torqeedo 2T 24V 4.8 knots 1200W** ~$4000
Hangkai 48/"5hp" 48V 3.8 knots 1000W ~$330
Minkota 35# 12V 2.3 knots 410W ~$150-170?
Newport 55# 12V 2-3 knots 550W ~$200

COMMENTS:

By far, we saw the best performance, speed, and torque from the Torqeedo. It might have done better, but I was limited by the battery cables and battery power. (The Torqeedo 2T is rated for 2400W max, but my setup could only hit 1200W.) If you want to go 5mph, the Torqeedo was the only thing I tested that would get me close to that. I have no experience with Epropulsion or other good candidates.

The Hangkai motors were something I had to try... They run about a tenth of the cost of similarly rated motors. However, they are EXTREMELY noisy, and don't inspire a tremendous amount of confidence. 48V batteries are also expensive and harder to find. The motor turns a small 3 blade prop that just isn't going to get you to 5mph. It's a much cheaper solution, but for the money, I'm much happier with the Newport (see below).

For completeness, I tested the dinghy with a 35 pound Minn-Kota trolling motor. These will run a LONG, LONG time on a good 12V Lithium (LFP / LiFeP0) battery. The most awkward thing about using a trolling motor on a dinghy is that MOST trolling motors have REALLY LONG shafts. They work, but it's a little annoying.

What I settled on for my dinghy is the Newport 55 pound 12V "Canoe Style" trolling motor. It's CHEAP (~$200) - if it dies, you won't cry. It's LIGHT. Easy for anyone to pick up. It's 12V - which means you can easily get a lithium 12V battery that is very light, and at 100AH, will run the motor at top speed for about 2 hours. No-name 100AH lithium 12V batteries are under $200 on Amazon. I like having a second one as backup if we're going to go very far.

Note: I somewhere recorded 3 knots with the Newport. On an actual ride to dinner one evening, we recorded 2.2 knots in the "real world". Your mileage may vary...

The best thing about the Newport combination is that the motor and the battery are both light enough that they can be easily handled, even by the admiral. They're also cheap enough to be reasonably "disposable" if something bad happens.

The biggest downside is the lack of speed. I did order an after market prop for the motor - but even with that, I don't expect much improvement. Maybe enough to measure, but certainly not more than a half knot of speed difference.

If you're retired, and have all the time in the world (and no bears or alligators chasing you), then maybe 2-2.5 knots is ok. You will never get to 5mph / 5 knots - the prop is just too small and doesn't have the pitch to do it. The physics just don't work. But if you don't mind going SLOW, the Newport is light, cheap, well built, and seems to be reliable.

 

[Marco Flamingo]

I'm now going on 5 years with my Newport 36 in saltwater. There is rust on the motor casing, but still runs fine. 5 years is a reasonable life and I should just buy another one and drop the old one off at Goodwill. Think of it as routine maintenance.

I don't know if I've ever looked at the phone to see speed. I'm lucky where I boat that there are too many other things to look at.

 

[amxr39]

One consideration is running against a current and still being able to get back to your starting point. Anybody comments on that?

 

[mvweebles]

Replying to both above: I went through the same process. Ultimately I opted for two dinghies. A 10 foot inflatable with the epropulsion for 90% of my shore trips and a 15.5 foot aluminum boat for fishing and longer trips. If you do go with an electric outboard, make sure it’s a established brand. I’ve noticed the startups are starting to go out of business.

I agree. Two dinghies is a very good solution. I'll add that a smaller dink and OB is much easier to drag up a beach and less likely to be stolen. The new SUP inflators make inflating and deflating super easy so storage of a small sink is possible even on my relatively small 36-footer

Peter

 

[skyhawk]

and less likely to be stolen

that was going to be my question as I read the thread....Seems like that when tied up to some dingy dock down in the islands, some of these electrics might catch a little more attention, and might also seem a little more portable.
but on the other hand, maybe a nice new small gas engine might be more appealing to the Ne'er-do-well since it's more universally serviceable.

I can imagine that @Takoradi 's trolling motor would work fine for most dingy usage, and I love the beauty in it's simplicity. What I see on my cruising daydream though is using the dingy for longer distance exploration around the anchorage and even beyond.
So yeah, two dingy's seems like a great idea...or maybe more accurately a dingy + a tender... if your boat is big enough for that.

 

[mvweebles]

that was going to be my question as I read the thread....Seems like that when tied up to some dingy dock down in the islands, some of these electrics might catch a little more attention, and might also seem a little more portable.
but on the other hand, maybe a nice new small gas engine might be more appealing to the Ne'er-do-well since it's more universally serviceable.

I can imagine that @Takoradi 's trolling motor would work fine for most dingy usage, and I love the beauty in it's simplicity. What I see on my cruising daydream though is using the dingy for longer distance exploration around the anchorage and even beyond.
So yeah, two dingy's seems like a great idea...or maybe more accurately a dingy + a tender... if your boat is big enough for that.

I doubt anyone would bother stealing an electric OB or a small OB. In lessor developed countries, a guy can make a living with a 15-20 hp outboard. When dinghys are stolen and then found, very common for the transom to be chopped out of the dinghy just to get the OB off of ASAP.

Peter.

 

[Mac2]

I bought the backpack made for the epropulsion battery just for the reason of fearing theft. Those floating batteries go for around $800.

 

[Mambo42]

I don't worry too much about someone stealing by electric outboard or just the battery. The battery is completely useless if you don't have the engine or the charger. You really need both for this battery to be useful to you.
If they want to steal the engine, that is possible, but then what are you going to do without the charger ? And even if you have the charger......if you don't have enough power onboard to recharge the battery........what is the purpose of that electric outboard ?

Normally what gets stolen a lot are the dinghy's and the engines are already on them. Who steals them in the Med ? The people who cannot afford a new dinghy so they steal a dinghy when they are about to leave the anchorage and yes.........they are blow boaters.
But if there is one thing they cannot use it is an electric outboard, so I basically don't worry too much.

 

[Delta Riverat]

I went with a Newport NT300 and a couple of LITime 36 volt 55AH batteries. Me thinks they will work well with the inflatable dingy but the boat and the batteries are still in the garage and the motor is in a fly bridge locker.