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nzjetboating.com Forums => General Board => Topic started by: Matthewf/Norbert/TuiDog on May 02, 2019, 11:48:17 AM

Title: Electric jet - donor ski
Post by: Matthewf/Norbert/TuiDog on May 02, 2019, 11:48:17 AM
Nikola.  Are releasing a electric jet ski that can be submerged.!

https://www.theverge.com/2019/4/17/18411541/nikola-wave-electric-jet-ski-4k-display-cruise-control
Title: Re: Electric jet - donor ski
Post by: Jeff B on May 02, 2019, 13:19:46 PM
Be nice and quiet.
Title: Re: Electric jet - donor ski
Post by: swifty on May 02, 2019, 17:50:47 PM
Cant see electric being any good for jet boating anytime soon.to much weight carrying your fuel around and it doesnt burn off and lighten your load as you go.
Title: Re: Electric jet - donor ski
Post by: Matthewf/Norbert/TuiDog on May 02, 2019, 18:58:38 PM
I think range will be an issue for us, maybe not a ski
Title: Re: Electric jet - donor ski
Post by: Warwick Marflitt on May 02, 2019, 20:18:16 PM
Electrick  scr vehicles will only limit the public ability to travel long distances quickly and freely! No green environmental preservationist is going to want anyone in or on the rivers. That's why they're making everyone fence and plant the river banks. Impenetrable blackberry and gorse guarantees no public  access?  hi- in 10 years well be able to jet boat and be hidden from view  ()()
Title: Re: Electric jet - donor ski
Post by: Henry on May 02, 2019, 21:02:19 PM
Your half baked conspiracy theories are getting a bit old Warwick. You've hijacked a fair few innocent threads with your politics.

Let stick to the subject.
Title: Re: Electric jet - donor ski
Post by: MRM on May 05, 2019, 20:17:33 PM
Back to electric boats....

When we were at shotover jet doing our induction a couple of weeks ago, the guy said they are currently building an electric boat there....Good application for it with the short trips they do.
Title: Re: Electric jet - donor ski
Post by: wairoacoastie on May 08, 2019, 09:42:07 AM
cant be far away before someone makes a sprint boat from electric . Power to weight ratio could be nuts
Title: Re: Electric jet - donor ski
Post by: Henry on October 10, 2019, 20:52:03 PM
https://taigamotors.ca/watercraft/

New donor ski for the super cashed up short distance jet boater.

270kg total weight , 180hp and 100kmph though, crap loads better than any other electric boat so far. 10mins of juice at WOT by my calcs though, i call BS on the claimed 2hr run time. Same amount of batteries as my car.

Give it time...
Title: Re: Electric jet - donor ski
Post by: bbs 540 on October 11, 2019, 21:12:07 PM
Shotover electric jets? Each of the main boats can do up to 20+ half hour trips per day and at peak times there are four operating at once. 10hrs boating at max load? times four boats that's a lot of battery power!
Title: Re: Electric jet - donor ski
Post by: Henry on October 12, 2019, 06:58:39 AM
They are planing to fast charge at the dock every time they load tourists.
Title: Re: Electric jet - donor ski
Post by: MRM on October 14, 2019, 15:57:36 PM
They are planing to fast charge at the dock every time they load tourists.

Exactly right, just don't let the tourists near the contacts!
Title: Re: Electric jet - donor ski
Post by: Jeff B on October 14, 2019, 16:57:10 PM
Hey Henry I was thinking of a "hybrid" type jet boat? Build the boat with the running gear from that fancy E-jetski (I cant afford one of them yet)
And build/buy a petrol charger, should be able to get a 50hp/40kg high performance petrol generator that clips into boat when needed for longer trips? Will give flexibility to run on battery alone (not for long) or generator as you boat.
Or charge with generator while you are at top of river?
Title: Re: Electric jet - donor ski
Post by: Henry on October 14, 2019, 19:59:07 PM
Yeah could work, my plan is to go for a tiny extremely light boat and use the biggest RC motors and controllers. Its cheap and grunty and the voltage can stay under 100v so no need for nasa grade safety. Mostly use it for playing around for 20min then go home.

I was just thinking of pinching a Honda 2kw generator initially then maybe a special grunty DIY generator if the hybrid system is a winner.

Wouldn't actually be that silly if you dont need to boat for miles. Just go have a play.

Lots of benefits in a tiny boat. Motor can just bolt to the intake and put the batteries where ever you like. Way less work to fit a boat out.

Pity there aint more 100mm jetski pumps good for 10,000rpm out there.
Title: Re: Electric jet - donor ski
Post by: blairx on October 16, 2019, 15:18:31 PM
I also want this, will you run it DC ? what will you do for a controller ?

 Shotover's PR exercise seems to be working already, even if the boat doesn't, unfortunately for them they haven't done their homework on the system engineer.

 Ski units are the way to go for sure. 
Title: Re: Electric jet - donor ski
Post by: Jeff B on October 16, 2019, 15:32:11 PM
The electric jetski is too expensive to use for a donor. Especially since you end up throwing half of it in the recycling centre....
Probably better to start from scratch?
I'm not sure how efficient the electric motors are? What rpm?
I thought a DC motor was pretty simple and the more amps you feed it, the more power you get?
Wouldn't a small electric car motor be better? They must be about 50kw?
Title: Re: Electric jet - donor ski
Post by: Henry on October 17, 2019, 09:45:48 AM
This is my starting point (4 kg, ~10,000rpm,~20+hp @300amp and 60V) https://maytech.cn/collections/all-brushless-motors/products/maytech-brushless-inrunner-motor-for-electric-surfboard-rc-boat-mti120116-200-sf

The controllers are fairly cheap as there is heaps of applications drones, RC cars, e-foils http://www.trampaboards.com/single-vesc-75v-300a-in-cnc-t6-silicone-sealed-aluminum-box--the-most-powerful-vedder-electronic-speed-controller-ever-p-26284.html

I have a big 20hp DC brushed motor but its 11kg  and not water cooled. Runs the ride-on mower. Nissan leaf donor would be the cheapest donor for a normal sized small boat (80kw) but i want a really small boat and it would be much more expensive experiment.

Watch this space for the baby hull to match.

Good subject for the GY pub Blair.
Title: Re: Electric jet - donor ski
Post by: Jeff B on October 17, 2019, 11:32:50 AM
10,000rpm is pretty high....
Are you going to try match a jet direct drive?
Or drive through a power robbing reduction drive? pop
Title: Re: Electric jet - donor ski
Post by: blairx on October 17, 2019, 12:18:00 PM
Cool, I need a dedicated Rees boat.

 How small would the hull have to be for 20hp to work ?

 The one Im looking at for the ute has peak efficiency at 8k rpm, my plan was to use a single stage planetary reduction, built by the fella that made the gearbox for the race boat, cheap and small. From what I understand the AC motors and controllers are now more efficient and cheaper than DC ( for cars anyway ).

 The GY pub is not ready for this level of advancement, that said I reckon there are more electric cars per capita there than anywhere.

 

Title: Re: Electric jet - donor ski
Post by: Henry on October 19, 2019, 09:44:11 AM
The hull is is a 20kg all up 2.4m plastic hull RIB (fairly indestructible hopefully), a 3mm alloy version would be ~30kg (less indestructible). Like this https://www.youtube.com/watch?v=qTzbhOcL97o
 but twice the power and half the weight and with out the stupid joystick.

Will be direct drive, i think it would be pretty crap to go to all the effort of making an electric boat only to listen to a gear box whining away. Motors loose ability to handle current and efficiency at below ~150KV (rpm/volt), hence to high rpm. crap for sucking rocks but shouldn't be an issue for such a small diameter pump. Maybe a lower RPM will be possible, someone just has to try it.

All the electric jet surfboards out there have similar power and weight and do 45-60km hr so its possible. I think us kiwis can do a better jet drive as well.

Will try it on my hotted up Kawasaki JS300 120mm pump first. That will be a big learning moment.

Most e-ute conversions i have seen are direct to the old transmission. Are you going direct drive to the wheels? Keen to see this

Yeah i think if you need any sort of decent performance AC motors are the norm.
Title: Re: Electric jet - donor ski
Post by: Jeff B on October 19, 2019, 11:58:32 AM
I'm thinking your 120mm Kawasaki pump is waaaaay to big? For this application?
Title: Re: Electric jet - donor ski
Post by: Jeff B on October 19, 2019, 12:03:47 PM
Something closer to this size?
Title: Re: Electric jet - donor ski
Post by: Henry on October 19, 2019, 18:21:55 PM
Haha what have you got cooking there?

About 100mm is what im thinking, we might sleeve the 120mm down after trying it full size.
Title: Re: Electric jet - donor ski
Post by: Paul on October 26, 2019, 00:10:31 AM
5KW motor, ~60mm impellor, ~5KG(??) all up weight.
Fairly decent speed (for a toy), but if you think about scaling up to carry people, the numbers get a bit silly.

https://www.youtube.com/watch?v=WhMKUmSEGPo
Title: Re: Electric jet - donor ski
Post by: Warwick Marflitt on June 01, 2020, 20:20:12 PM
Any progress with this?

https://www.maxongroup.com/maxon/view/content/aquatic-solutions

https://www.maxongroup.com/maxon/view/category/motor?etcc_cu=onsite&etcc_med_onsite=Product&etcc_cmp_onsite=EC-i+program&etcc_plc=aquatic-solutions&etcc_var=%5bcom%5d%23en%23_d_&target=filter&filterCategory=EC-i

These might have more grunt RC Outrunner electric motors

https://www.espritmodel.com/esprit-elite-200cc-e105-30-125-3d-hd-outrunner-brushless-motor-w-telemetry.aspx

https://www.flyinggiants.com/forums/showthread.php?t=190156
Title: Re: Electric jet - donor ski
Post by: Warwick Marflitt on June 01, 2020, 22:08:53 PM
Might get some ideas from this guys setup

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

Or use electric Car DC Brushless wheel motor

https://www.aliexpress.com/premium/car-hub-motor.html?d=y&spm=a2g0o.detail.1000012.7.68796dabsmIz3E

Title: Re: Electric jet - donor ski
Post by: Jeff B on June 03, 2020, 14:57:05 PM
I did some rough calculations and the electric option is not weighing up well....literally....
Just get so much more energy per kg from burning fossil fuels unfortunately.
My battery grinder or skill saw just eats batteries.
For short bursts would be ok like a sprint boat?
But the cost of lightweight high performance batteries is still prohibitive for most of us old, stuck in the past type jet boaters  ;)
There is still a lot of development to be done inaking the jet unit more efficient?
Title: Re: Electric jet - donor ski
Post by: blairx on June 04, 2020, 19:46:29 PM
 Im sort of intending to pursue this, I bought a 10Kva turbine genset which currently makes 300A or so of DC at 28V, I want to put a bigger generator on it ( maybe 48v ) then run a 48V motor on a small unit in a 2 seater.

I expect the result wont be quiet, fuel efficient or light but I want it so f**k it.

 Anyone have good sources for oddball generators etc ? Google says many modern hydrid cars are 48V, pure electric ususally higher.
Title: Re: Electric jet - donor ski
Post by: powerwill on June 04, 2020, 21:29:37 PM
I like the bit in the jet ski add where it says zero maintenance, the only thing I know that goes in salt water and requires zero maintenance is a fish!
Title: Re: Electric jet - donor ski
Post by: PM on June 04, 2020, 22:36:56 PM
Im sort of intending to pursue this, I bought a 10Kva turbine genset which currently makes 300A or so of DC at 28V, I want to put a bigger generator on it ( maybe 48v ) then run a 48V motor on a small unit in a 2 seater.

I expect the result wont be quiet, fuel efficient or light but I want it so f**k it.

 Anyone have good sources for oddball generators etc ? Google says many modern hydrid cars are 48V, pure electric ususally higher.

That's only about 7.6kW or 10hp. Might need to go bigger
Title: Re: Electric jet - donor ski
Post by: Warwick Marflitt on June 05, 2020, 10:27:38 AM
External combustion engine
Use  "fire" to make "steam" to "generate electricity" to run "electric motor" to drive  high pressure water jet "pump" sh st
Indirect drive
VS
Direct drive
Internal combustion engine
"Petrol engine" driving water "Jet pump"

Newtons 3rd law "For every action, there is an equal and opposite reaction".

What's required! is a 5th dimension engine?...... Jeffffff!!! whats in ya shed?

https://en.wikipedia.org/wiki/Five-dimensional_space
Title: Re: Electric jet - donor ski
Post by: blairx on June 05, 2020, 20:41:38 PM
You need to cut some cardboard out of your diet chief.

What I have is an engine and some time, so I'm going to try something I haven't tried.

Or should I build a series of identical LS powered snooze cruisers and call them perfection because I don't have the spine to try anything different ?
Title: Re: Electric jet - donor ski
Post by: Jeff B on June 06, 2020, 05:58:16 AM
Blair how heavy is that generator? Must be pretty light?
If its 10kva does that mean it's nearly 10kw electrical output? (12hp ish)?
I would like to build a very quiet (super quiet) little boat but I need about 25kw (35kw if it's getting heavy) but not sure whether to invest in internal combustion engine and sound deadening system or some other way?.
 pop
Title: Re: Electric jet - donor ski
Post by: Warwick Marflitt on June 06, 2020, 06:23:26 AM
No go for it. If Bill Hamilton had not persisted and tried none of this shenanigans and Electronic truffle growing would be happening.... my comments are reverse encouragement designed to get the "Ill show em"! Juices flowing in you....anything trieds better than nothing being attempted..... It's fun to experiment and learn about  B))T
What hull and jet unit are you going to use
Title: Re: Electric jet - donor ski
Post by: Paul on June 06, 2020, 09:59:35 AM
Blair how heavy is that generator? Must be pretty light?
If its 10kva does that mean it's nearly 10kw electrical output? (12hp ish)?

My 6KVA continuous/6.5KVA peak generator, is nearly 100KG.

The KVA -> KW conversion, is nearly equal for a purely resistive load.  The conversion is not normally not equal with inductive/capacitive/AC loads/electronics/etc.
Google 'power factor'. https://www.google.co.nz/search?q=power+factor
Title: Re: Electric jet - donor ski
Post by: Paul on June 06, 2020, 11:55:43 AM
I bought a 10Kva turbine genset which currently makes 300A or so of DC at 28V, I want to put a bigger generator on it ( maybe 48v ) then run a 48V motor on a small unit in a 2 seater.

Gensets typically are ridgidly RPM governed, so 'throttling' an electric supply could be tricky?  You might need to remove all the governor?

Why go through all the extra energy-conversion steps (chemical > mechanical > electrical > batteries/speed-control? > mechanical > water pump) with the losses at every stage?  Given what you know about turbines, why not just unbolt the alternator off the genset, and direct-couple a small-diameter ski-pump to it (chemical > mechanical > water pump)?  You didn't mention the RPM it turned, so you may need a stage of epicyclic between the turbine and pump.  Every stage of energy conversion, looses more potential output/performance..
Title: Re: Electric jet - donor ski
Post by: Jeff B on June 06, 2020, 12:43:10 PM
My 6KVA continuous/6.5KVA peak generator, is nearly 100KG.

The KVA -> KW conversion, is nearly equal for a purely resistive load.  The conversion is not normally not equal with inductive/capacitive/AC loads/electronics/etc.
Google 'power factor'. https://www.google.co.nz/search?q=power+factor

How much energy is lost in conversion Paul? I know a 5hp petrol engine on a generator only puts out about 2000w electricity. But that's mostly because the "5hp" petrol engine @3600rpm is only rated for 3.5hp continuous @3000rpm.
Isn't the interislander ferry set up with internal combustion engines running generators, running electric motors driving props? Same as a lot of trains?  I would think if the energy efficiency lost was much it wouldn't be viable?
Or is it that small scale it's hard to get efficient?  ii
Title: Re: Electric jet - donor ski
Post by: blairx on June 06, 2020, 13:25:45 PM
 For this turbine thing the engine / gearbox setup has a 10Kva max rating on the engine data plate, Im assuming this just allows for different generators.
 It has a 12V starter and 28V DC gen right now but Ive worked on them before with 115V AC generators as ground power units and attached in aircraft ( SKycranes and Chinooks ) where we used them to generate hydraulic pressure aswell. Big combine harvesters use them as start units aswell ( Solar IH )

 The race boat uses a 48V starter / generator so Ive mucked around at that voltage before, I figure if hyrbids use them it gives me a fighting chance of getting the controller gear for it, that and I was given a big 48V battery.

 ENgine weight is about 30 kg, 103kg as it sits with this generator so maybe 170kg or so by the time you add a battery and motor on the pump, not light, or good on fuel @ 30 litres per hour.

My plan was to put it in a 2 seater , itll only get used on the dart and rees most likely.

if the electric thing turns into an octopus I can pull the engine off this , mess with the fuel system and should be able to get 200hp or so out of it, bolt a power turbine and gearbox to it and run  that, but Ive done that a few times but the flat torque curve / jet unit match up is pretty appealing
Title: Re: Electric jet - donor ski
Post by: Paul on June 06, 2020, 16:09:17 PM
How much energy is lost in conversion Paul? I know a 5hp petrol engine on a generator only puts out about 2000w electricity. But that's mostly because the "5hp" petrol engine @3600rpm is only rated for 3.5hp continuous @3000rpm.
Unsure Jeff - google may help.  When you've only got a marginal power source to begin with, adding more energy conversion steps/ power losses, should probably be questioned.

Isn't the interislander ferry set up with internal combustion engines running generators, running electric motors driving props? Same as a lot of trains?  I would think if the energy efficiency lost was much it wouldn't be viable?
I think the internal-combustion > electric > mechanical is probably used on ferries/trains, for control reasons.  Speed/ reversing requirements would be changing often and electric gives immediate control.  If you take a container ship (where absolute efficiency is paramount), the prop is hard bolted to the crank - to go in astern, involves stopping the main engine, altering the cam-profiles (injection timing etc), and air-starting again in reverse!...
Title: Re: Electric jet - donor ski
Post by: allforham on June 06, 2020, 22:39:46 PM
Interesting thread. I'm sure it'll be viable one day once battery technology can compete with power density and cost of fossil fuels. For now makes more sense for cars and yachts etc needing much lower constant power requirements and possibility of regen under braking or sailing. I thought trains etc were diesel electric to help getting huge loads moving. Would need a pretty serious gearbox?
Title: Re: Electric jet - donor ski
Post by: swifty on June 07, 2020, 12:45:51 PM
You need to cut some cardboard out of your diet chief.

What I have is an engine and some time, so I'm going to try something I haven't tried.

Or should I build a series of identical LS powered snooze cruisers and call them perfection because I don't have the spine to try anything different ?
you are gonna have to keep it small .
Title: Re: Electric jet - donor ski
Post by: blairx on June 07, 2020, 14:24:04 PM
Paul, are you able to help me with some range calculations on this thing ? To me it's a hybrid with battery providing the motor power and the genset recharging it. Looks like many ev's use dc/DC converters to ramp system voltage up for the motors which opens the options right up. 

If I work backwards and say I want to run a 100hp DC motor , an 8kw 48v generator on the genset and want it to run for 40minutes boating with the turbine running, what other info would be needed to figure out how much battery I would need ?
Title: Re: Electric jet - donor ski
Post by: Jeff B on June 07, 2020, 21:31:33 PM
I cant help with your calculations Blair...
But I'll ask more questions haha...
So your aim is to run a full electric motor/jet setup with batteries.
And the turbine is a range extender?  So the battery will still be going flat with the generator running? (Fepending on load)
Is your aim to be able to cruise using the generator only?   
Title: Re: Electric jet - donor ski
Post by: blairx on June 08, 2020, 07:14:11 AM
Yes yes yes no, I don't see the turbine being able to supply the current for the motor without battery storage aswell, but ideally it runs for half an hour or so, I stop and let the turbine scream away for a while and top it up. The turbine doesn't need water or motion.
 
I'm sure it'll be a hit at tin stops, I'm guessing its over 70db running
Title: Re: Electric jet - donor ski
Post by: allforham on June 08, 2020, 08:27:07 AM
Have a bit of experience with off grid power systems and charging batteries with a generator is always seen as a last resort due to being extremely inefficient and expensive. Also not sure on availability of chargers to get any real range into batteries with a jetboats power requirements without taking hours. I guess the tesla fast chargers etc do it but must be some serious technology involved? Sounds like a fun project regardless
Title: Re: Electric jet - donor ski
Post by: Jeff B on June 08, 2020, 08:47:36 AM
Yes yes yes no, I don't see the turbine being able to supply the current for the motor without battery storage aswell, but ideally it runs for half an hour or so, I stop and let the turbine scream away for a while and top it up. The turbine doesn't need water or motion.
 
I'm sure it'll be a hit at tin stops, I'm guessing its over 70db running

OK that's what I was thinking. So for a smallish, lightweight (300-350kg) 2 person (3mish) boat you need minimum 20kw to plane, 30-40kw to cruise and 100kw to have some fun.
So in really simple terms, your 10kw generator will need to charge batteries at a ratio of roughly 4:1 ? For general cruising.
Boat for 1 minute, charge for 4 minutes?
Boat for 5 minutes, charge for 20 minutes?
How long you will go for will depend on battery size/capacity? But obviously  with more battery capacity = more weight = more kw required....

These jet boats really are quite inefficient aren't they....
No wonder electric airplanes are not popular yet.....
Title: Re: Electric jet - donor ski
Post by: PM on June 08, 2020, 09:54:01 AM
Paul, are you able to help me with some range calculations on this thing ? To me it's a hybrid with battery providing the motor power and the genset recharging it. Looks like many ev's use dc/DC converters to ramp system voltage up for the motors which opens the options right up. 

If I work backwards and say I want to run a 100hp DC motor , an 8kw 48v generator on the genset and want it to run for 40minutes boating with the turbine running, what other info would be needed to figure out how much battery I would need ?
100hp is about 75kW.
1W is 1 Joule of energy per sec

So if you are running your generator as you are boating, then the generator will provide about 10% of your energy requirements.

Storage is measured in Watt hours (Wh) or multiple of, ie kilowatt hours (kWh), megawatt hours (MWh) etc.

But batteries don't like to be cycled much beyond 20% DoD (Depth of Discharge) without risking damaging the battery

for 40 mins of run time with the gen running the storage equation would look like this.

75kW x 40/60 [minutes to hours conversion] x 0.9 [percentage required from battery] x 1.2 [DoD requirement] = 54kWh

This doesn't take into account parasitic losses inside the system, ie losses from motor, voltage droop in wiring, losses in the controller etc.

An NS70 battery weighs 18kg, is 12V and holds 70Ah. 12V x 70Ah gives 0.84kWh

54kWh [minimum storage requirement] / 0.84kWh [Single battery storage capacity] = 64.3 batteries x 18kg = 1157kg of battery storage.

There are better batteries with better energy density (more kWh per kg) but they do tend to get pretty spendy.

Title: Re: Electric jet - donor ski
Post by: blairx on June 08, 2020, 10:25:38 AM
Haha, thanks gents, that's a much better way of looking at it. When we tried to see if it would work for the race boat we got to a 1.6 ton pack that needed to be changed up the river, ideal.

I have this battery , 48v, 156AH lipo ev thing, it won't be cheap to control or charge / manage but it's close to designed for the purpose at least, it weighs 20kg or so.

 This could be a 2 minute boat

Title: Re: Electric jet - donor ski
Post by: Warwick Marflitt on June 08, 2020, 10:46:36 AM
You can always work backwards. If you know the pump size and volume of water by using Water pumping Formulae. The numbers will answer the questions.....

https://www.mtp.com.au/engineering-design/pumping-formulas/

There are various ways through which pump input power may be calculated. Below we?ve listed down a pump power formula for every given measurement.
Title: Re: Electric jet - donor ski
Post by: blairx on June 08, 2020, 11:01:05 AM
For a pump I assumed a 150mm ski pump would be best based on target hp, efficiency and that the motors I've seen all have peak efficiency up over 7k rpm.

 For practicality if it can do 50kph thats enough for me, I have fast boats too.

But if it needs a ton of batteries then it's shot anyway, maybe take advantage of the current cashgrab and get charging stations put up the river ?
Title: Re: Electric jet - donor ski
Post by: PM on June 08, 2020, 13:07:25 PM
Haha, thanks gents, that's a much better way of looking at it. When we tried to see if it would work for the race boat we got to a 1.6 ton pack that needed to be changed up the river, ideal.

I have this battery , 48v, 156AH lipo ev thing, it won't be cheap to control or charge / manage but it's close to designed for the purpose at least, it weighs 20kg or so.

 This could be a 2 minute boat

That's 7.5kWh for 20kg.

So back to your 56kWh requirement then

56kWh / 7.5kWh = 7.5 of those batteries.

8 [because you can't use half a battery] x 20 = 160kg!

That becomes do-able, as long as those batteries aren't $moon-beams$
Title: Re: Electric jet - donor ski
Post by: blairx on June 08, 2020, 13:38:13 PM
Yeah right, that's closer then, I got this one as a present but can get more


It makes the ev's look pretty efficient, the missus has a 40kwh leaf that'll do 250km with me beating it
Title: Re: Electric jet - donor ski
Post by: Jeff B on June 08, 2020, 14:09:04 PM
Yeah right, that's closer then, I got this one as a present but can get more


It makes the ev's look pretty efficient, the missus has a 40kwh leaf that'll do 250km with me beating it

I guess another way to look at it.
Most jet boats burn about 1 litre fossil fuel per km?
Half that for a little boat?
That's roughly 10x worse fuel economy than a car.... jaw
Title: Re: Electric jet - donor ski
Post by: blairx on June 08, 2020, 14:20:59 PM
True, which also backs up the range calculations if the boat has a 40kwh pack itll do 25km
Title: Re: Electric jet - donor ski
Post by: Warwick Marflitt on June 12, 2020, 23:36:06 PM
If the hull was made up of two dissimilar metals insulated from the other and in multiple groups. The hull could become the batteries charger? The water the electrolyte. You are using a battery to charge your batteries... And if you can get the electric motor to generate power by tethering it in the fast flow in the river while you are away hunting for Big Hoof....the water flowing through the jet unit will turn the impellers driving the motor/generator and charge the batteries at the same time....if you can reverse the polarity of the hull plates and stop/reverse the electrons so that the hull doesn't dissolve away you can call the boat Perpetual Air...
Because it will never go flat....
Title: Re: Electric jet - donor ski
Post by: Ross Goldsack - JBNZ President on June 13, 2020, 09:19:51 AM
It's mushy season.......
Title: Re: Electric jet - donor ski
Post by: swifty on June 13, 2020, 23:05:41 PM
It's mushy season.......
You gotta love his thinking outside the square . But he does seems to have a supply all year round   ;D :o
Title: Re: Electric jet - donor ski
Post by: Warwick Marflitt on June 14, 2020, 00:00:17 AM
You gotta love his thinking outside the square . But he does seems to have a supply all year round   ;D :o

They've been growing like weeds for the past few months.
Check out this ion propulsion system.
https://youtu.be/IorDYGI1uqc
Title: Re: Electric jet - donor ski
Post by: mallyxt on June 24, 2020, 20:28:45 PM
Hamiltons have a hybid drive looks like the toyota style system
https://seawanderer.org/hamiltonjet-unveils-electro-hybrid-drive-system
Title: Re: Electric jet - donor ski
Post by: Henry on June 25, 2020, 10:08:56 AM
Now thats interesting!

Reckon you can rig that mini turbine with a electric motor inline Blair? Might need some smart software though.
Title: Re: Electric jet - donor ski
Post by: Warwick Marflitt on June 25, 2020, 17:59:24 PM
Auckland company developing something here

https://www.facebook.com/voltaicelectricjets/

https://www.nzmarine.com/directory/business/voltaic-innovations-ltd

https://www.electricjets.nz/

Advertising for electrical engineer too

https://www.seek.co.nz/job/50135665?type=standout#searchRequestToken=32eb7411-4b28-4790-a4bd-6411e213c401
Title: Re: Electric jet - donor ski
Post by: Jeff B on July 01, 2020, 07:09:17 AM
https://www.trademe.co.nz/2683704084