Tesla Scooter - three phase electric scooter

[jeffpicks]

COOL! I didn't realize it was also a musical instrument! Can you make it play "Mary Had A Little Lamb" when you drive down the road?

[jeffpicks]

Frederic M, is that you?

[VaadRock]

1st congratulations for your job...its very nice and impressive!! if you upload more details about how you do the conversion that would be great!! 2nd you are not a MACEDONIAN...you cant denial the facts of history!!! (Read some historical books...specifically when yugoslavia created and after that)...!!!

[tezzvids1]

I say a job well done . I like the way the motor sings when you speed it up.

[paulie1982]

Very cool

[lit2010ny]

best part of the video was the random guy digging on the side of the road...

[dtiydr]

"It has a reverse gear!"

Would love to see that going backwards in 50km/h..

[eujeeves]

all it needs are blue neon el wires and you're finally in TRON. cue tron music...

[jimmymagnum07]

It sounds cool :p

[N41J4]

The future is finally here... People can ride Piano's!

[makav3lirise]

super vam je skuter

[BluesCat1980]

That thing is awfully loud for an electric motor.

[knowledgemonger]

Happy New Year guys.

Will you get it to market this year?

[ackovski]

That is why we eliminated the regenerative braking, because you get very little for a lot of work... not that we could not do it. We will do it, but when we do it, we want it done right. We still haven't got a laboratory like we should with all instruments needed. We have lack of funds and that would be a maybe if we find an investor.

[ackovski]

I have read much about hub motors... my opinion... personally I think that they are a VERY bad idea. There is no suspension and amortization inside the wheel, the whole beating and vibrations from the road are going straight on the motor. There is no such ball bearing that would handle that torture. And it would not be a durable machine. The motor on our scooter is at the same place as the gasoline one and is well protected.

[Aleks7923]

what you should do, is to try copy the idea from ellica car, the electric motor is built-in wheel

[knowledgemonger]

Putting the motor inside the wheel increases the unsprung weight. Unsprung weight is the enemy of good handling on rough roads. The lighter the wheel assembly is the better so long as the strength is maintained.

These guys appear to be doing everything just about right.

[ackovski]

A three phase brushless hub-motor is a bit complicated and we have no funds to do such complicated machine... unfortunately. This way you can put a motor with a desired strength just by changing few screws (if you have the space of course). This is a prototype still but has the potential of these things if correctly designed.

[knowledgemonger]

I assume that it is a variable frequency and voltage induction motor.

Did you do dynamic braking?

[ackovski]

Yes it is a variable and no, there is no dynamic braking. The calculations showed that complicating the scooter that much to get regenerative braking can only harm the batteries and you get so little that is not worth doing it. You get 1% less, but much longer life. Vectrix had that problem, you drive the scooter 10min on a downhill and you kill the batteries because the charging current was 40A!!! Insane!

[knowledgemonger]

I wouldn't think that a dynamic braking system would add much. It seems to me that if you just decrease the frequency of switching the MOSFETs below sych, the real component of the power into the motor goes minus. This would send energy back to the batteries.

Where is my thinking wrong on this part?

[ackovski]

Charging current of the batteries has limit of some 3 amps. The regenerative braking sometimes gives a lot of amps, sometimes up to 100 or more. That would boil the batteries in a minute if not limited. Complicating the electronics of the scooter to limit that current on 3 amps and get 5 minutes of charging on a downhill is not worth. This design is simple and eliminates many troubles that we are aware of. That is the problem that Vectrix had and this one doesn't.

[knowledgemonger]

Yes, I agree. At least for this battery type, regenerative braking isn't a good idea.

These are sealed lead acid batteries I assume and you have about 30 amp hours worth of them. I base this on the C/10 rule for charging.

[knowledgemonger]

That looks like a nice little battery powered scooter but the batteries look too small to give much range. What is the range with those batteries? Are they Lithiums?

[ackovski]

Well, this is still a prototype. We didn't want to waste a lot of money for testing. The batteries are Lead acid and (so far) it has a range of about 10-15km depending on how you drive it. The batteries weight about 50kg. The charging time is about 5 hours. We expect that Lithium would cut the weight of the batteries more than a half, about 23kg. The charging would be 2 hours and the range would be more than 50km since the Lithium has three times the capacity for the same volume.

[knowledgemonger]

It would also be a good idea to move the batteries lower. Perhaps if you (in production) can get flatter profile batteries and place them inside the foot deck.

A low C of G makes a bike handle better.

Lithium Vanadium batteries will be a better option than normal Lithiums. The new ones have a much greater number of charge cycles and about 7 times the energy of a lead acid. They are expected to be available in 2010 over the counter.

BTW: The name Tesla is already taken.

[ackovski]

The batteries are in the space for the helmet because that is an Chinese 50cc scooter that we ripped apart and converted it into a electric scooter with a 3 phase motor. If this idea starts a mass production, I'm sure the batteries would have a way appropriate space. And we are planning on LiFePO4 batteries.

About the Tesla name... Nikola was Tesla and Tesla was a Serb. His second name means adze! Tesla Motors use that name because they use his motor... the way we do too, but not on a car!

[ackovski]

I pretty know much in details about Tesla Roadster as a machine and the name of it because we had an offer from Tesla Motors to move and live in the U.S. and work for them. The offer was denied because we like the way of living here in Macedonia... at least so far!

[ackovski]

By the way, this video is made in a cold weather. As we have read the spreadsheet, the Lead batteries have a nasty effect to have 50% of the capacity when its cold and 120% on a very hot weather. It is December now, so we expect to have at least 25km with one charge at summer! I hope so. :)

[ackovski]

And there is a space for another pack of batteries in front of the seat, meaning more than double range since the current draining would be reduced at start!

[bait28]

@knowledgemonger lead-acid

[knowledgemonger]

@bait28 Yes, I know that the batteries are lead acid. If they are seal lead acid, the problems with over charging are greater than with the normal car battery sort. With the sealed battery, you can't add water. Also the charge rate on the sealed ones is generally lower. Normally you need about 10 hours to charge up a sealed battery. With the unsealed type you can go faster and add water.

[bait28]

@knowledgemonger your mcomment "Are they Lithiums?'omment. i responded to that. lol

[knowledgemonger]

@bait28 Someone else had already set me straight on that.

[bait28]

@knowledgemonger and i couldn't see that...

[knowledgemonger]

@bait28 Yes, these sorts of misunderstanding are common in youtube. It happens all the time.

[bait28]

@knowledgemonger i call it the youtube effect.