Electric Outboard Motor

[StuM]

Originally Posted by newhaul

The one thing the op didn't say here is what voltage the motor operates at there are already well establishes electric outboards with 48 volt operating power. Electric Outboards | ReGen Hybrid Electric Marine Power and Elco Motor EP-9.9 check their existing bussiness models

Doesn't really matter since we are talking about dedicated engine batteries and Watts.

[GordMay]

Greetings and welcome aboard the CF, Jackson.

➥ Pure Outboard FAQ | Pure Watercraft

[newhaul]

Originally Posted by StuM

Doesn't really matter since we are talking about dedicated engine batteries and Watts.

Actually stu I would think it would matter what voltage to compete with existing tech a 48 volt 9.9 HP electric motor is $4800 USD plus you make your own battery so voltage and battery cost would be something as a consumer I would need to know to estimate the cost difference of different systems as well as charging setups for them

[newhaul]

Originally Posted by GordMay

Greetings and welcome aboard the CF, Jackson.

➥ Pure Outboard FAQ | Pure Watercraft

That's the one discussed over on SN last week

[leftbrainstuff]

3 hrs at full throttle sounds a little ambitious. Or you have a giant battery pack.

You'll need to be price competitive and have a fast recharge capability.

Ability to charge in a day from 200 to 1200W solar will also be a USP.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[Stumble]

Stu,

As always thanks for the catch I have a bad habit of using the wrong terminology and I appreciate the correction.

Again just looking at the numbers, to recharge the 90kwh battery pack you would need to run a 30amp shore power cord at max output for 30 hours, assuming a 100% efficient battery charger to get back to full charge. So every two days you can go out for 3 hours... Not a boat I would want to buy.

[StuM]

Originally Posted by Stumble

Stu,

As always thanks for the catch I have a bad habit of using the wrong terminology and I appreciate the correction.

Again just looking at the numbers, to recharge the 90kwh battery pack you would need to run a 30amp shore power cord at max output for 30 hours, assuming a 100% efficient battery charger to get back to full charge. So every two days you can go out for 3 hours... Not a boat I would want to buy.

I see on their Facebook page that they boast about plugging their trailered boat into fast charge EV stations and "filling up" for free. If you are prepared to disconnect and lug 16 power packs to the nearest station, you could do it in an hour or three* with a DC Level 2 or 3 power point

*Note: no margin of error stipulated - YMMV

[PureWatercraft]

Let me clarify a few points. I started Pure Watercraft, the company that the OP was studying. This project was for a UW entrepreneurship class, and the students came here to this forum to find out what the market thought.

Some of the details they posted were right, and some were not. I want to make sure we leave this forum with the right info, directly from the source.

POWER
Our motor is rated at 20 kW continuous power. That translates directly to 26.8 HP; however, our prop is indeed more efficient than existing props, so it gets more propulsion than a gas motor of the same power. (Reasons: gas outboards run ~ 3000 RPM, while we run ~ 1500 RPM, with larger diameter prop, and we have full torque starting at 0 RPM, while gas motors have very narrow RPM zones in which they reach rated torque. Proof: we consistently outrun boats with 30 HP gas outboards, both from a dead stop and at top continuous speed.)

We will market our outboard at different power levels, because there are distinct markets for them; however, it will be the same motor inside. So if you get the 9.9 HP version, you can run on lakes that limit power to < 10 HP and be legal, but get more propulsion than others with 9.9 HP gas outboards.

RANGE
As Stumble initially pointed out, our outboard does not go full throttle for 3 hours (without an inordinate volume of batteries). With a single battery pack it can go 27 minutes at 12 kW, and with two battery packs it can go 33 minutes at 20 kW.

If you use two battery packs, and go for 3 hours at constant power, using the full usable capacity, you'll be using about 3.7 kW, which is about 5 HP, and the propulsion would be equivalent to about 6-7 HP from a gas outboard. With a low-wake launch, we go about 10 mph at that power. So our range with that hull is about 30 miles with 2 battery packs running at 4 kW.

BATTERY PACKS
Our motor works exclusively with our own battery packs. We focus exclusively on high performance systems; there is no sense in combining our very high power density motor with very low energy density batteries (especially because our voltage would drive an impractical setup of 12V batteries). Our packs can be combined for larger capacity. Using our own packs exclusively allows us to run more safely, as we can ensure affirmative communication between battery pack and motor in every case, and prevent running under adverse battery pack conditions.

Our battery packs have nominal capacity of 6 kWh and usable capacity of about 5.5 kWh. Voltage is 350V, which allows us to achieve much higher power density than other electric outboards (more than double that of the lower-voltage Torqeedos, for example). In prototype, our battery packs weigh 99 lbs, but we expect that the production version should weigh less (maybe 85 lbs?).

For those who compare our energy density to that of LiFePo4, ours is better, because Li-NMC is an inherently more energy dense chemistry. We include a thermal limiting material in our battery packs to ensure they keep at a healthy temperature.

CHARGING
We have two chargers: 120V 1 kW, and 240V 10 kW. The math on charging times is pretty straightforward; if you use 2/3 of a 12 kWh system (two battery packs), then using our 1 kW charger, it will take about 8 hours to nearly fully recharge (there is some additional time at the end to balance the cells). Our packs have a charging speed limit of 1/2 of their capacity per hour (to preserve battery health and cycle life), so even with our 10 kW charger, you could only charge at 6 kW if you were using two of our battery packs. The chargers can each charge multiple boats and battery packs at once.

OUTBOARD MOTOR
It weighs 91.8 lbs in prototype, and should weigh about 15 lbs less in production. The motor is in-line with the 8:1 gear set and the prop, underwater. The noise is extremely low, below that of all other electric outboards we've seen. Its efficiency is very high, partly due to the high voltage, which leads to lower current and lower heat losses.

TOTAL SYSTEM WEIGHT
Our minimum total system weight in prototype is 190 lbs, and in production we expect it to be about 160 lbs. With two battery packs (which is the minimum configuration to get our total rated power of 20 kW), our system weight is 289 lbs in prototype, or expected weight of about 245 lbs in production.

For comparison, an equivalent power gas motor to our minimum configuration is 15 HP. The Honda 15 HP weighs 104 lbs. Add a 33 lb starter battery and filled 3 gallon gas tank (20 lbs) and you get a total system weight of about 157 lbs. So our production system is at virtual weight parity.

An equivalent gas motor to our 2-pack configuration is 30-40 HP. The Honda 30 HP weighs 160 lbs. Add a 33 lb starter battery and filled 6 gallon tank (40 lbs) and you get a total system weight of about 233 lbs. So our production system is about 12 lbs more

In each case, it's important to note that our weight comes mainly from the battery packs, so the transom weight is much less than with a gas outboard.

APPLICATION
It's a great motor for regular use, and for low to moderate range. As some pointed out, lakes are great, because there is a well-known limit to how far you'd need to go. This is not the best motor for going long distances infrequently (unless you place a very high premium on quiet operation or zero emissions, such as on bodies of water that prohibit internal combustion engines). For those who nearly always run at low to moderate range, but have to go a long distance once a year, it might be worth switching to a gas outboard for that one outing, and keeping the vast majority of outings quiet and clean.

Thanks!

Andy Rebele
Founder
Pure Watercraft

[PureWatercraft]

Originally Posted by StuM

I see on their Facebook page that they boast about plugging their trailered boat into fast charge EV stations and "filling up" for free. If you are prepared to disconnect and lug 16 power packs to the nearest station, you could do it in an hour or three* with a DC Level 2 or 3 power point

*Note: no margin of error stipulated - YMMV

Sorry if that was confusing. The 2012 post about charging at a public charging station referred to a 2012 prototype runabout we built as a learning project. Among other things, we learned we don't want that to be our first product. The outboard motor is our company's focus.

[Terra Nova]

Except for a tiny trolling motor, NOTHING would prompt me to want an electric outboard in the sizes you mention.

[newhaul]

Originally Posted by PureWatercraft

Let me clarify a few points. I started Pure Watercraft, the company that the OP was studying. This project was for a UW entrepreneurship class, and the students came here to this forum to find out what the market thought.

Some of the details they posted were right, and some were not. I want to make sure we leave this forum with the right info, directly from the source.

POWER
Our motor is rated at 20 kW continuous power. That translates directly to 26.8 HP; however, our prop is indeed more efficient than existing props, so it gets more propulsion than a gas motor of the same power. (Reasons: gas outboards run ~ 3000 RPM, while we run ~ 1500 RPM, with larger diameter prop, and we have full torque starting at 0 RPM, while gas motors have very narrow RPM zones in which they reach rated torque. Proof: we consistently outrun boats with 30 HP gas outboards, both from a dead stop and at top continuous speed.)

We will market our outboard at different power levels, because there are distinct markets for them; however, it will be the same motor inside. So if you get the 9.9 HP version, you can run on lakes that limit power to < 10 HP and be legal, but get more propulsion than others with 9.9 HP gas outboards.

RANGE
As Stumble initially pointed out, our outboard does not go full throttle for 3 hours (without an inordinate volume of batteries). With a single battery pack it can go 27 minutes at 12 kW, and with two battery packs it can go 33 minutes at 20 kW.

If you use two battery packs, and go for 3 hours at constant power, using the full usable capacity, you'll be using about 3.7 kW, which is about 5 HP, and the propulsion would be equivalent to about 6-7 HP from a gas outboard. With a low-wake launch, we go about 10 mph at that power. So our range with that hull is about 30 miles with 2 battery packs running at 4 kW.

BATTERY PACKS
Our motor works exclusively with our own battery packs. We focus exclusively on high performance systems; there is no sense in combining our very high power density motor with very low energy density batteries (especially because our voltage would drive an impractical setup of 12V batteries). Our packs can be combined for larger capacity. Using our own packs exclusively allows us to run more safely, as we can ensure affirmative communication between battery pack and motor in every case, and prevent running under adverse battery pack conditions.

Our battery packs have nominal capacity of 6 kWh and usable capacity of about 5.5 kWh. Voltage is 350V, which allows us to achieve much higher power density than other electric outboards (more than double that of the lower-voltage Torqeedos, for example). In prototype, our battery packs weigh 99 lbs, but we expect that the production version should weigh less (maybe 85 lbs?).

For those who compare our energy density to that of LiFePo4, ours is better, because Li-NMC is an inherently more energy dense chemistry. We include a thermal limiting material in our battery packs to ensure they keep at a healthy temperature.

CHARGING
We have two chargers: 120V 1 kW, and 240V 10 kW. The math on charging times is pretty straightforward; if you use 2/3 of a 12 kWh system (two battery packs), then using our 1 kW charger, it will take about 8 hours to nearly fully recharge (there is some additional time at the end to balance the cells). Our packs have a charging speed limit of 1/2 of their capacity per hour (to preserve battery health and cycle life), so even with our 10 kW charger, you could only charge at 6 kW if you were using two of our battery packs. The chargers can each charge multiple boats and battery packs at once.

OUTBOARD MOTOR
It weighs 91.8 lbs in prototype, and should weigh about 15 lbs less in production. The motor is in-line with the 8:1 gear set and the prop, underwater. The noise is extremely low, below that of all other electric outboards we've seen. Its efficiency is very high, partly due to the high voltage, which leads to lower current and lower heat losses.

TOTAL SYSTEM WEIGHT
Our minimum total system weight in prototype is 190 lbs, and in production we expect it to be about 160 lbs. With two battery packs (which is the minimum configuration to get our total rated power of 20 kW), our system weight is 289 lbs in prototype, or expected weight of about 245 lbs in production.

For comparison, an equivalent power gas motor to our minimum configuration is 15 HP. The Honda 15 HP weighs 104 lbs. Add a 33 lb starter battery and filled 3 gallon gas tank (20 lbs) and you get a total system weight of about 157 lbs. So our production system is at virtual weight parity.

An equivalent gas motor to our 2-pack configuration is 30-40 HP. The Honda 30 HP weighs 160 lbs. Add a 33 lb starter battery and filled 6 gallon tank (40 lbs) and you get a total system weight of about 233 lbs. So our production system is about 12 lbs more

In each case, it's important to note that our weight comes mainly from the battery packs, so the transom weight is much less than with a gas outboard.

APPLICATION
It's a great motor for regular use, and for low to moderate range. As some pointed out, lakes are great, because there is a well-known limit to how far you'd need to go. This is not the best motor for going long distances infrequently (unless you place a very high premium on quiet operation or zero emissions, such as on bodies of water that prohibit internal combustion engines). For those who nearly always run at low to moderate range, but have to go a long distance once a year, it might be worth switching to a gas outboard for that one outing, and keeping the vast majority of outings quiet and clean.

Thanks!

Andy Rebele
Founder
Pure Watercraft

OK Andy so all proprietary for your system then now for the big question a price breakdown of your parts and components

[svmariane]

Originally Posted by PureWatercraft

Let me clarify a few points. I started Pure Watercraft, the company that the OP was studying. This project was for a UW entrepreneurship class, and the students came here to this forum to find out what the market thought.

Some of the details they posted were right, and some were not. I want to make sure we leave this forum with the right info, directly from the source.

POWER
Our motor is rated at 20 kW continuous power. That translates directly to 26.8 HP; however, our prop is indeed more efficient than existing props, so it gets more propulsion than a gas motor of the same power. (Reasons: gas outboards run ~ 3000 RPM, while we run ~ 1500 RPM, with larger diameter prop, and we have full torque starting at 0 RPM, while gas motors have very narrow RPM zones in which they reach rated torque. Proof: we consistently outrun boats with 30 HP gas outboards, both from a dead stop and at top continuous speed.)

We will market our outboard at different power levels, because there are distinct markets for them; however, it will be the same motor inside. So if you get the 9.9 HP version, you can run on lakes that limit power to < 10 HP and be legal, but get more propulsion than others with 9.9 HP gas outboards.

<snip>

For those who nearly always run at low to moderate range, but have to go a long distance once a year, it might be worth switching to a gas outboard for that one outing, and keeping the vast majority of outings quiet and clean.

Thanks!

Andy Rebele
Founder
Pure Watercraft

Okay. I'm already contemplating purchasing another electric outboard for our tender, so your information is interesting. Our current electric outboard - a Torqueedo Travel 1003 - would shift to our (back up) Walker Bay dinghy.

For your marketing folk:

Intended usage:
-mounted on a 10' tender to our 48' sailboat,
-saltwater environment,
-will charge via mother-ship's solar/wind facility,
-almost daily usage when in port,
-emergency use as "tug boat" when/as needed (us or neighbors),
-9.9 HP sounds nice; 15/20 HP sounds lovely,
(would appreciate mobility even when winds/waves kick up),
-weight and cost are driving factors.

(Weight: because the whole tender most come out of the water at night to help avoid theft.)

We've already switched from gas to electric outboard(s) and intend, if at all possible, to maintain that position.
So there's one input.

James

[valhalla360]

The reminds me of a Dilbert thread where it ends with the engineering department launching an attack on the marketing department for promising a product that can never be built (at least not at anything remotely close to a reasonable price)

Talk about more efficient props and torque at RPM, is pure marketing. If they could achieve enough improvement to be noticeable they would put them into production on traditional outboards.
- It violates the laws of physics to claim a 30hp electric motor will outrun a 30hp gas motor at top speed, HP is HP, If anything the gas motor will have the edge when the gas boat has a 5gal tank that weights in around 30-40lbs and the electric to get the same range has to drag around a "tank" that weighs hundreds of lbs. (assuming 18-20ft runabout)
- Changing the batteries type or voltage doesn't substantially improve the storage capacity in comparison to gasoline. If they could come in remotely close, tesla would have a 2000mile range, charge in 5 min and cost $20k. I'm certain they have better tech and engineers than a small startup outboard company.

Bottom line: If you have a magic system that will out perform a diesel or gas engine in every aspect at a lower price, of course, you would quickly dominate the market. No need for marketing. It will sell itself.

Sorry if this comes across as harsh but it is so far from reality, its just silly.

[offpist]

Hello.
I just want to show this video of Torqeeedo 4.0 on my Walker bay dingy.
The batteries come from an EV car and therefor really cheap.

https://www.youtube.com/watch?v=jb5Cv6Lypw0

The 18 kg engine is really easy to remove and mount, battery is 23,8 kg.

I have two batteries, so if i need to go really far i can just bring both with me and change under way.

Top speed is 24,9 KM/H.

[Electric Ray]

Originally Posted by offpist

Hello.
I just want to show this video of Torqeeedo 4.0 on my Walker bay dingy.
The batteries come from an EV car and therefor really cheap.

The 18 kg engine is really easy to remove and mount, battery is 23,8 kg.

I have two batteries, so if i need to go really far i can just bring both with me and change under way.

Top speed is 24,9 KM/H.

At last! A recent post of an electric outboard with lithium batteries actually working, well done

Most posts I have found so far are just tyre kickers or detractors and date from long enough ago that all this was too hard/heavy/expensive.

How far can you get on a single battery pack one up on a perfect day like your video?

Thanks for your video

Mark