T-Pain Is On A Boat: Re: [Electric Boats] 24V to 96V Operating Range from a Single Outboard

You are so right on two key issues. First let me say that anyone who is looking for a "cheaper" way to replace the tired old petrol motor and save money up front, electric is not for them. Electric is for those who boat regularly and want to improve their boating experience while looking long term for their return on investment through maintenance and repair, as well as petrol savings. The right electric kit at the right power level will do that for them.

There are a number of options for battery packs and battery chemistry, depending on range and performance expectations. Your example of 2 hours on plane is a typical expectation for someone looking to reach planning speeds with electric. As far as planning speeds go, lithium ion is the only way to go and yes, I mean lithium ion, not LiFePO4. LiFePO4 is too heavy. I am recommending used Tesla Model S modules. These modules are 24V, 5.3kWh each with the discharge capability of 500A continuous, and 750A peak when water cooled. I am not recommending water cooling, as that is not necessary to meet the Stealth's max continuous current of 180A for the 20HP version and 240A for the 40HP version. At those current levels, the discharging is below 1C, the rated discharge. Most smaller, lighter boats can plane with 12kW. Two hours is 24kW. Allow a 20% buffer, 28.8kWh pack will get it done. You will get pretty close with four of the Tesla Model S modules in series for the 20HP. Six modules are required for the 40HP, providing a total of 31.8kWh, more than enough. The modules weigh only 55 pounds each, so a 20HP pack will weigh 220 pounds and a 40HP pack is 330 pounds. The cost of the modules are $1,200 each. A proper charger, BMS and display for a 20HP system is $1,435 and for a 40HP system, $1,710. Total for a 20HP system is $11,035 and a 40HP system is $18,909.

I am also working on my own lithium ion battery module to reduce cost and weight even further.

Once again, thank you for your insight.

Scott

On Fri, Jul 12, 2019 at 9:52 AM Kev captainyoung@gmail.com [electricboats] <electricboats@yahoogroups.com> wrote:

I do think there is a market for an more affordable electric outboard, comparing to Torqueedo. But the problem is you are competing against gas outboards too. And when you factor in the cost of batteries + outboard, the electric option is several times the cost of an outboard. So your average customer will never pay that much. Even guys like us, who are very interested in an electric boat, will have a hard time justifying the substantially more expensive electric outboard vs a proven gas outboard for a lot less.
9.9 HP Gas outboard is around $2000
Electric outboard is $4800 + batteries, which can be several thousand dollars. How much would an average battery pack for this cost? A pack that can get you 2 hours of run time on a plane?

So your only target customer is wealthy people.. And wealthy people will not have cost as a major factor. And when you compare your overall cost to Torqueedo's overall cost, a few thousand difference for the outboard will not be a big factor in their decision making. Having said that, as battery prices drop, the electric outboard will become more viable. So at some point in the future, from a business viewpoint it might work.
Right now, for small boats, electric outboards are starting to make financial sense, because they only need a small battery. But as you need more and more power, the battery gets so expensive, that it is not worth it yet.
That's just my opinion. But I do think what you have accomplished so far is really awesome, and I hope that you are successful.
What are the options for batteries? What are you using? Do you plan to package batteries with your outboard?

On Thu, Jul 11, 2019 at 9:42 PM Scott Masterson smasterson2@gmail.com [electricboats] <electricboats@yahoogroups.com> wrote:

Thank you so much for your input. It is truly appreciated. I think you are correct on the lower end being a questionable fit. Certainly Torqeedo's "Travel" line is the right choice for those looking for under 4HP, but the "Cruise" line puzzles me. Here's what I don't understand....

Why do they rate the Cruise 2.0 as 5HP, the 4.0 as 8HP and the 10..0 as a 20HP? According to their specs sheets, the 2.0 has 2kW input power and 1.12kW propulsive power. That's the equivalent of 2.68HP input power and 1.5HP propulsive power and their efficiency rating is only 56%. Maybe they are having problems with dispersing heat from the motor. It's in the water. Why isn't it more efficient? Is the casing plastic or have a problem with heat transfer?

Same thing with the Cruise 4.0. Rated as 8HP, yet the input power is 4kW and the propulsive power is 2.24kW. That's only 5.36HP and 3HP respectively.. Very strange. I don't even feel the need to go to the 10.0. I think you get the idea as to why I am confused.

The new motor I am proposing is using a motor and controller combination that is over 90% efficient at voltages from 48V to 96V. The input power at 48V is 8.64kW or 11.58HP with a propulsive power of 6.91kW or 9.26HP. Compare that to the Cruise 4.0's 5.36 input HP and 3 propulsive HP. At a price of $4,499 for the Cruise 4..0, is $4,800 to make more than twice the propulsive power a worthy alternative?

Here is how the Cruise line stacks up against the Stealth:

Model    Nominal Voltage    Weight    Propulsive Power    Price
Cruise 2..0 24V    35 lbs.. 1.5HP    $3,999
Cruise 4.0 48V    37 lbs. 3HP $4,499
Cruise 10.0 48V    137 lbs. 7.5HP    $8,999
Stealth@48V    48V-96V 110 lbs. 9.26HP    $4,800
Stealth@96V    48V-96V 110 lbs. 18.43HP    $4,800

Again, I want to thank you for your candid opinion. I'm looking forward to any additional insight you may have. As before, good, bad or indifferent, all feedback is very valuable.

PS, did you like the videos? I especially like the one of me and the wife. I really didn't mean to scold her. She's the best!

Scott

On Thu, Jul 11, 2019 at 9:39 AM Kev captainyoung@gmail.com [electricboats] <electricboats@yahoogroups.com> wrote:

Well done, but I think for the low hp models most people will go with torqueedo or a gas outboard. Brand new 6hp gas outboard is under $1500. So I doubt many will pay 3 times that, and still need batteries.
On the high hp motors you might do ok, but you need to compete with torqueedo on price and quality.
Good luck

On Tue, Jul 9, 2019, 12:56 AM smasterson2@gmail.com [electricboats] <electricboats@yahoogroups..com> wrote:

My name is Scott Masterson

I produce the Stealth E40, a true 40HP electric outboard. I am writing the group to ask the groups opinion of what level of interest may exist in an electric outboard that can be operated in pack voltage ranges from 24V to 96V.

Though the Stealth E40 has enjoyed some level of success, it is somewhat limited to it's customer base because it is built on a 144V system. While the motor's price point of under $10,000 is very competitive, a proper battery pack, BMS, charger and monitor will nearly double the price.

I have been approached a number of times to produce a smaller outboard, say around 20HP. I thought about it and it seems to me that the best solution may be a single outboard that used the right components and was built in such a manner that the customer can make a one time purchase in the outboard of $4,800 dollars, then choose the pack voltage that best suits their performance requirements and be budget sensitive at the same time. If one wanted only a 24V pack to operate at 6HP, then four 6V golf cart batteries will do nicely. For those who need more power, the same outboard can deliver 24HP with a 96V pack.

At the same time, the right design should be lightweight, under 100 pounds, to make possible use on lighter small boats. This will be done by removing the more sensitive electronics out from under the cowl and placing them in a water proof case where the user can remove the case after use. The outboard will house only the motor. Phase wires will be fed through the lower cowl and attached easily with a single one piece Anderson quick connect. Likewise, the DC power pack connections will connect in the same way with a single one piece Anderson quick connect. No 12V logic accessory will be necessary.

This is only in the concept stage at this time, although I have used each and every component previously in similar applications, so I am confident in the concepts success.

Here is a video from years ago where I had put together a 48V outboard using a similar concept. It is a little crude, but I think you will get the idea.
https://www.youtube.com/watch?v=E1mMKSqkRWs
https://www.youtube.com/watch?v=rlaX9LBGKHI

Also, I am attaching pics of the outboard lower leg being considered and a drawing of how the portable electronic components case may be look. All input, good or bad, will be appreciated.

Scott Masterson
Stealth Electric Outboards
713-391-6550
https://www.boatingmag.com/fin d/stealth%20e40
https://www.youtube.com/watch? v=n91YQKpKceQ
https://www..youtube..com/watch? v=58EL4NupWmw
http://www..evworld.com/focus.c fm?cid=378
https://www.stealthelectricout boards.com/