Help Needed with Fastest possible Electric JetSki Conversion

Boats, Jet Skis, Kayaks etc., including hovercrafts
Post Reply
campbell1987   1 mW

1 mW
Posts: 15
Joined: Apr 20 2015 7:43am

Help Needed with Fastest possible Electric JetSki Conversion

Post by campbell1987 » Oct 19 2017 5:26am

Title says it all really, I have my eye on an engineless Yamaha GP1200R for converting to electric, My only question is with todays motor technology what would be the fastest i would be able to get out of an all electric ski with or without the help of gears, I have owned a 2004 seadoo gtx 185 before and liked it alot just hated the work involved for winterising etc and HATED filling the f***er up with fuel, I think batteries are the way to go, I've built a nice 52v 750w bbs02 powered mid drive downhill ebike with help from the guys over at pedalecs forum, (they pointed me here for higher powered builds so here i am :-)
Here's a pic of the bike..

https://drive.google.com/open?id=0BwNrE ... 3FHa3cwRVE

Anyway the plan here is build something to outrun a standard ski if possible, Just thinking with that big engine and fuel tank gone it leaves a lot of room for batteries and a decent motor, Plus i think i could keep the weight even lover down in the hull so should be a lot more stable to ride,

This really is just a thought at this stage, Im just hoping some folks here can help me make it reality.. ;-)

campbell1987   1 mW

1 mW
Posts: 15
Joined: Apr 20 2015 7:43am

Re: Help Needed with Fastest possible Electric JetSki Conver

Post by campbell1987 » Oct 20 2017 7:15am

Anyone any ideas? I know water and electric dont mix but that doesnt mean i should keep it low voltage, Ill just have all connections well insulated, would i be safe enough using LiPos or should i use the older style 18650 LiIon cells as they have a harder metal shell?

User avatar
amberwolf   100 GW

100 GW
Posts: 30787
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Help Needed with Fastest possible Electric JetSki Conver

Post by amberwolf » Oct 21 2017 1:58am

Before you get to batteries, you need to know how much power you'll need from the motor system to drive the propulsion system and make the vehicle run the speeds you want.

If you know how many HP it used to be, you can use that as a base starting point, but I don't know if it's going to need more or less power than that as electric just to do what it did before. Then you need to figure out how much *more* power you need to make it go the speeds you want out of it. (it's probably not a linear relationship; it wouldn't be in air and water is probably worse).

There's a few threads in this forum section about various conversions and builds that discuss power levels and speeds, planing, water drag, etc., (none of which I really know anything about), which should help you figure out what you'll need.


Once you know what the continous and peak power levels ahve to be, *then* you can find or design a battery that can output at least that much without sagging in voltage or heating up.

User avatar
liveforphysics   100 GW

100 GW
Posts: 14137
Joined: Oct 29 2008 1:48am
Location: Santa Cruz, CA, USA

Re: Help Needed with Fastest possible Electric JetSki Conver

Post by liveforphysics » Oct 21 2017 4:46am

Nissan leaf motor is not a bad starting point, but still won't be fastest possible and the pack voltage I a boat may mean a pile of dead noob EV builders

Tesla motor rear motor would get you in the ballpark for fastest, but it has the same voltage drama/hazard. Buying a modern Zero SR/DSR and gutting it's drivetrain for your boat would likely get you something running with good results you enjoy using,but won't be fastest.
Each carcinogen vapor exposure includes a dice roll for cancer.

Each mutagen vapor exposure includes a dice roll for reproductive genetic defects in your children.

Each engine start sprays them into a shared atmosphere which includes beings not offered an opportunity to consent accepting these cancer experiences and defective genetics life experiences.

Every post is a free gift to the collective of minds composing the living bleeding edge of LEV development on our spaceship.

campbell1987   1 mW

1 mW
Posts: 15
Joined: Apr 20 2015 7:43am

Re: Help Needed with Fastest possible Electric JetSki Conver

Post by campbell1987 » Oct 24 2017 6:23am

Next question.... Where can i buy a tesla motor.... I looked at that electric bike but its a bit outside my budget.... wouldnt have really said i had a budget till i seen that, :D Yes it would be a good motor but i dont have that much spare cash lyin about to buy a new bike just for 1 part, I dont mind splashing out on a decent motor though as i may use it for a few builds if it lasts, Guessing used parts from theses tesla cars are rare since they are so new, and i bet the cost bit new too. Just hope you dont tell me i need to buy a Tesla to strip for parts..lol

Quinc   100 W

100 W
Posts: 121
Joined: Apr 18 2016 11:21am

Re: Help Needed with Fastest possible Electric JetSki Conversion

Post by Quinc » Nov 27 2017 2:13am

You are going to need a water cooled motor and it is going to cost you way more then what you could buy a gas powered ski for.. But anyway check out the Gratis:
https://www.engadget.com/2017/03/08/fre ... atercraft/

mrzed   100 W

100 W
Posts: 239
Joined: Feb 06 2009 6:48pm
Location: Victoria Canada

Re: Help Needed with Fastest possible Electric JetSki Conversion

Post by mrzed » Nov 29 2017 10:44pm

Yup, water cooled is the trick, and there's not much out there. Someone with skills and tools could come up with badass custom heat exchange setup to properly cool a suitably powerful electric motor. doubtless someone already is, and it will be released in a year or two by an existing oem like bombardier or a well funded startup.

kbeck247   1 µW

1 µW
Posts: 2
Joined: Dec 21 2017 5:46pm

Re: Help Needed with Fastest possible Electric JetSki Conversion

Post by kbeck247 » Dec 21 2017 6:23pm

R-mamba has watercooled brushless motors and some really high power controllers as well for good prices. Also don't even look at the tesla powertrain...its so expensive. But if you have $10k to dump into powertrain, there is a controller system for the tesla powertrain. The ev-controls t1c. Its $3500 though. Powertrain from a tesla is $3-7k depending on where you can get a hold of it and which models. But the weight is really high which weight is more important in water than on land. A Nissan leaf motor is VERY powerful. In the car it is actually very underpowered. I have seen 300-400+ horsepower out of them and they have liquid cooling. Plus they weigh less. Look up the electric crx on youtube. That person builds up a controller to use on a Nissan leaf motor and drops it into a light weight car. As far as price goes, the leaf motor is a good cheap option. But before you decide, check the weight of your jet ski with everything out of it and get measurements of the space you have to work with. Then decide what can even fit in there... Jet skis don't have much space to work with when you figure in the controller, motor, and batteries. Based on your goals you are looking at small amounts of high discharge Lipo or a decent amount of high discharge lithium ion cells. With good 10c 18650's out now, I would lean towards the lithium ion cells. Give the measurements of your space so everyone knows what you have to work with.

jccrew1982   1 µW

1 µW
Posts: 1
Joined: Mar 24 2019 10:48am

Re: Help Needed with Fastest possible Electric JetSki Conversion

Post by jccrew1982 » Mar 24 2019 11:15am

Hello, I am sorry if I am posting this request for help in the wrong section but I am very serious about completing my own jetski conversion. Having been a couple years since this thread was active, i am curious if you or anyone else has since completed a decently fast electric personal watercraft? If so, please point me towards some decent hardware to look into as I am certainly going to be giving this build a shot.

A little about me; I recently got out of the US Navy after almost 20 years. I would humbly say that I have a above average understanding of the fundamentals of electricity to, at the very least, shock myself. Ok, ok, only mostly kidding.. My undergrad was in Electrical Engineering, but my Naval training was in Nuear Propulsion (yeah, wouldnt that be nice for private implementation), and power distribution. That being said, i am attacking this hobby with a very humble mind and hoping that someone can point me towards a cost effective build plan as I am certain that I am not the first to want to do this. Thanks in advance, and I hope to chat with some of you soon.

warm regards,

Johnny

WesleyEllett   1 µW

1 µW
Posts: 1
Joined: Sep 10 2019 2:44pm

Re: Help Needed with Fastest possible Electric JetSki Conversion

Post by WesleyEllett » Sep 10 2019 3:09pm

I’m about to put a jet ski motor on a 55 gallon drum diy boat build. Filling this thread. Ima gonna make a two person man cave of a boat and put one of these motors on it. I’m guessing a 2 stroke gas motor is what I’ll use for speed, I want a nice electric motor as a supplement or alternative motor.
Looking forward to posting pics and seeing y’all.
Semper Fi
(Gonna go from Fort Worth Texas to the Gulf of Mexico, 710 miles.

User avatar
methods   10 GW

10 GW
Posts: 4748
Joined: Aug 08 2008 12:08pm
Location: Santa Cruz CA
Contact:

Re: Help Needed with Fastest possible Electric JetSki Conversion

Post by methods » Sep 16 2019 12:55pm

jccrew1982 wrote:
Mar 24 2019 11:15am
Hello, I am sorry if I am posting this request for help in the wrong section but I am very serious about completing my own jetski conversion. .....
Johnny

The only review I ever heard, from an expert, of an actual electric Jet Ski implementation was that it was underwhelming. Going on that singular datapoint I would suggest going BIG on power. As much motor, controller, and battery as you can possibly fit.

Schedule half your time for Ingress Protection from the water, or 3/4ths your time if it is Salt Water.

...
...

I am currently eyeballing a speed boat down at the harbor. One of those deals that just has a V8 sitting on the rear deck and an inboard. You can pick them up for nothing with a bad motor.

To... duplicate that kind of wicked raw power... would mean gutting not one but two modern EV's.
Hmmm.....

Boils down to Budget.
Mine looks like this:
20190330_111323.jpg
20190330_111323.jpg (6.32 MiB) Viewed 4144 times
That is what my current EV budget is looking like. I hope yours is looking better.

Post Progress pics once you get off the ground.



-methods
Increasing battery voltage and controller current limit will result in a non linear experience

gkramer   1 µW

1 µW
Posts: 1
Joined: Feb 15 2020 5:55pm

Re: Help Needed with Fastest possible Electric JetSki Conversion

Post by gkramer » Feb 15 2020 6:17pm

Not sure if anyone still monitoring this original post. Brand new today. Just extremely interested in the same project. I work at a marina and am also a former navy nuke. I have several old waverunner hulls and was looking at options for alternatives beyond original 2 stroke engine. The 800 was around 80 hp and the 1200 was around 130 hp. Just quickly looking at an impulse 9 and lithium batteries and simple controller, I'm at around 300 lbs (Very comparable to ICE) and $6,000. Would be fun, but not economically feasible. Bottom line.......If you still wanna try, you can get old hulls for $0-$200 all day long. For $7000 I can get two older 4 stroke skis or a brand new 4 stroke ski or a prototype electric ski with half the HP.......all would be fun in different ways....all would meet 2006 EPA emissions requirements.

kingofl337   1 µW

1 µW
Posts: 1
Joined: Jul 28 2020 10:06am

Re: Help Needed with Fastest possible Electric JetSki Conversion

Post by kingofl337 » Jul 28 2020 10:19am

Just an FYI: https://robotics.ee.uwa.edu.au/theses/ Search everything that contains "REVski". It's an ongoing thesis at University of Western Australia.

The limitation seems to be finding a reasonably priced motor the output needs to be around 50hp/50ft-lbs at around 6,000rpm for the low end and 120hp/75ft-lbs using an older chassis. Using a new chassis the weight is higher the power requirements is higher.

Hillhater   100 GW

100 GW
Posts: 11042
Joined: Aug 03 2010 10:33pm
Location: Sydney ..(Hilly part !) .. Australia/ Down under !

Re: Help Needed with Fastest possible Electric JetSki Conversion

Post by Hillhater » Jul 28 2020 6:48pm

You do not need a Phd or even consider the options for an EV ski for very long, before you realise that there is a “catch 22” to this.
For a decent performance ski you need decent power, 75-100kW or more.
And to drive that power you need batteries of suitable performance and capacity for a minimum run period.
So even that 75 kW ski, to run for 30 mins, needs 20-30 kWh of battery capacity.
That ends up weighing 125-150 kg of battery alone...the equivalent of one.. (or two ?), .passengers on board before you start...
That instantly reduces the performance !compared to a similarly powerful ICE ski
More power needs more battery which just increases the weight further.
You could of course compromise the run time ..15 min ?... but then youwill reduce your “Fun” time also.
Electric powered small boats are practical for low power, low speed situations...Trolling motors, Canoes, Kayacks, etc,..but not for speed applications...
..not until much better battery technology is available.
This forum owes its existence to Justin of ebikes.ca

User avatar
efMX Trials Electric Freeride   1 MW

1 MW
Posts: 1742
Joined: Feb 15 2013 4:43pm

Re: Help Needed with Fastest possible Electric JetSki Conversion

Post by efMX Trials Electric Freeride » Jul 28 2020 8:37pm

some ride & sk8 videos:
metacafe.com/channels/NATAS666DAMIEN
http://www.youtube.com/natas666damien
i have nothing for sale.. :)

Post Reply