The electric Jet ski!!

kevbo

kevbo

Location
dfw
Electrics have better power/weight over internal combustion but very little endurance. This is why they work so well for drag racers and little else.
 
NVJAY775

NVJAY775

My home away from home.
Location
Gardnerville, Nevada, United States
I would love to be able to ride a standup on Tahoe. It gets descent waves. And the elevation issue would be non-existent. I'm actually looking forward to getting the wife a 4-stroke couch, just so I can ride Tahoe. I'm 30 minutes away from a launch.
 
smoofers

smoofers

Rockin' the SQUARE!!!!
Site Supporter
Location
Granbury, TX
ryan said:
true that. but it will get sunk buy someone. what about the heat ? has to be vented somewhere. put 3 peolpe on it it will be upside down in 5 mins. lol it will never be sold in the us. sue sue sue
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Um.... you are complaining about heat.... on a WATER craft......

Watercraft have the luxury of this cool concept called WATER COOLING. Like said before by another poster, put water passages in the speed control's heat sink, and heat is no longer an issue.... Any thing that heats up on a ski can potentially be water cooled.

Again, it all comes down to having batteries that store enough power and provide enough current to sustain a fun ride.
 
firemedicmonkey

firemedicmonkey

Erie Surf & Ski
Location
Erie Surf and Ski... Cleveland, OH
smoofers said:
Um.... you are complaining about heat.... on a WATER craft......

Watercraft have the luxury of this cool concept called WATER COOLING. Like said before by another poster, put water passages in the speed control's heat sink, and heat is no longer an issue.... Any thing that heats up on a ski can potentially be water cooled.

Again, it all comes down to having batteries that store enough power and provide enough current to sustain a fun ride.
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And are light enough and affordable enought to make it practical!... On land the weight of the batteries can be used as a traction aid... on the water it only limits capacity, speed, and manueverability!
 
firemedicmonkey

firemedicmonkey

Erie Surf & Ski
Location
Erie Surf and Ski... Cleveland, OH
right but if the thing is so heavy it won't get out of the water very far reqardless... It's like my couches... my 96 xp with 110 hp launches twice as high as my 06 RXP with 230 hp... power to weight is king!

don't get me wrong I am excited b/c this could be really cool... lightweight unlimited torque that would be awesome... Plus I am an engineer at heart and love to see new ideas...

There is someone on here that is building an electric SXR out of Djkorn's old hull...
 
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227

227

Its all about the surf!
Location
Oceanside, CA
kraqus said:
The only way someone will ever be able to ride the surf is with a "non-emissions" Jetski.

Benny
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Jetskis aren’t banned from the surf because they are powered by 2 stroke motors, they are banned from the surfline because they are powered by a motor period. An electric jetski would be banned from surf riding just as any internal combustion powered ski is. The “surf zone” or 200 yards from shore is off limits to all motor powered boats/jetskis because this area is considered a swimmers/surfers zone. Like pedestrians in the street, swimmers and surfers both have priority in the surf zone. If they could perfect the electric jet ski they will surely make them in couches before stand ups. And if they were legal to ride in the surf how long do you think they would remain legal with all the Bozo couchers zipping around through all the swimmers and surfers thinking how cool they are that they can out perform some guy paddling around on a surfboard? Benny you need to move close to someplace were you can ride in the surf
 
Maxumflux

Maxumflux

Location
Knoxville, TN
227 said:
Jetskis aren’t banned from the surf because they are powered by 2 stroke motors, they are banned from the surfline because they are powered by a motor period. An electric jetski would be banned from surf riding just as any internal combustion powered ski is. The “surf zone” or 200 yards from shore is off limits to all motor powered boats/jetskis because this area is considered a swimmers/surfers zone. Like pedestrians in the street, swimmers and surfers both have priority in the surf zone. If they could perfect the electric jet ski they will surely make them in couches before stand ups. And if they were legal to ride in the surf how long do you think they would remain legal with all the Bozo couchers zipping around through all the swimmers and surfers thinking how cool they are that they can out perform some guy paddling around on a surfboard? Benny you need to move close to someplace were you can ride in the surf
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i need surf to..
 
Berky

Berky

Location
Fl
I would guess it would take about 56,000 watts to do a flat water back flip with every thing totally dialed in (pump,prop,rpm,load) thats 150lbs of batt.(Lith). WFO=7mins ; 1/2 load=15mins ; 1/4 load=30mins
Every thing is there to do it, motors,controllers and to some degree the batterys. If the batterys get much better it could get shocking.
 
stanton

stanton

High on jetskis.
Location
atascadero,ca
cooling shouldnt be much of a problem, its not on a gas motor!
unsinkable electric jetski, sounds pretty cool if it runs for 45mins and doesnt weigh any more.
i think the weight is the killer, electric cant compete with power to weight ratio of a internal combustion engine.
 
O

old-man-on-couch

Location
New Jersey
Berky said:
I would guess it would take about 56,000 watts to do a flat water back flip with every thing totally dialed in (pump,prop,rpm,load) thats 150lbs of batt.(Lith). WFO=7mins ; 1/2 load=15mins ; 1/4 load=30mins
Every thing is there to do it, motors,controllers and to some degree the batterys. If the batterys get much better it could get shocking.
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You're pretty close to exactly right, and the funny thing is that's only 20% more than the requirement to get something with enough power to be fun. We're about 1 year into the project (we didn't think it would take 6 months...) and it's astonishing how much power is required to make an electric jet ski work well.

But you're a little off on the run time. picture a jet pump like a jet engine. It doesn't work at 1/2 or 1/4 power. It only works from 85% load to 110% load. This is what makes the task so difficult, and run times so bad right now.

We've got a drive that works (probably enough for the first electric back-flip in the spring...) but it's getting the economics of enough batteries to make it run for a decent amount of time that is proving to be an even greater challenge than making it work in the first place.

Lots of folks are working on it (I've spoken to most of them), and there should be several viable choices in the coming year.

I'm probably the only one here that's ridden one, and I can tell you that it's not the power or the run time you'll notice, it's the eerie quiet... The torque is really nice, and you can get used to the other differences, but the quiet is just freaky!

If anyone has questions, just send me a PM or an email.

Alan Kroeper
(x-h2o: old-man-on-couch)
Revolt Hydrosport
ak@ejfengineering.com
 
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O

old-man-on-couch

Location
New Jersey
firemedicmonkey said:
Newtons Laws... "Energy can not be created or destroyed.... It can only change form..." So when you run electric motors, just like gas motors... There is heat created that has to be dissapated or it will overheat just like a gas motor... Except when batteries and electic motors overheat they just don't blow a head gasket and quit... The blow literally!:261: The biggest heat offender is prolly the speed control or rheostat... Its a big variable resitor which basically eats up current by heating up to control speed... It is basic job is to just turn energy into heat...



p.s. There is a guy in the New Jersey area building atleast and 80 hp SXR... out of DJkorn's old Stock SXR Hull... There is a couple threads around here about it... :splatt:
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Well, we're not quite at 80hp... But DJKorn's ski should still be pretty cool. And it should be a little lighter than when DJ rode it.

The good motor controllers don't have too much of a heat issue, and the batteries have been pretty well behaved as far as heat goes.

Heat is an issue for IC engines because they're so inefficient (2/3 of the energy goes to heating up the water...); the electric setup is between 80%-95% efficient, depending on load. At this point, only very minor provisions have had to be made for cooling...

Alan Kroeper
Revolt Hydrosport
 
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