126-Volt Nikola

[Ben Kim]

10 minutes ago, chrisjunlee said:

The power bricks you're using is itself a step down transformer with a rectifier. Step up/down is determined by coil ratio. In other words, nothing will change from user perspective.

 

I know this, my point is US outlets are 110V (120V), so its no longer feasible to step down.  Will it step up, or will we need to get a converter for the USA?

[chrisjunlee]

1 minute ago, Ben Kim said:

I know this, my point is US outlets are 110V (120V), so its no longer feasible to step down.  Will it step up, or will we need to get a converter for the USA?

The same mechanism to step down can be used to step up. Literally all that changes is the coil winding ratio inside the brick:

As an extreme example: you can step up to 1000 volts from a 1 volt AC source - it just would have very low current and silly low efficiency.

[Marty Backe]

41 minutes ago, meepmeepmayer said:

If we assume the 100V Nikola can do 65kph/40mph, that means an 80kph/50mph 126V Nikola

Why are they even doing this? Who wants to ride that fast? I wonder what other reasons than speed made them do this.

Interesting!

I think there are other potential benefits. Efficiency (longer range), acceleration, etc. 

[Lucas Alexander Oliver]

I am a layman when talking terms like voltage, amps amp hrs. All that. I think  In regular terms like. Range acceleration top speed.  Does a higher voltage system make all these values better ? 

[Marty Backe]

13 minutes ago, Lucas Alexander Oliver said:

I am a layman when talking terms like voltage, amps amp hrs. All that. I think  In regular terms like. Range acceleration top speed.  Does a higher voltage system make all these values better ? 

We don't have any emperical evidence regarding range (yet), but generally, higher voltage wheels equates to everything being better.

If the 126-volt model is available in a standard 84-volt configuration (1600wh) then we'll be able to do the very first range comparison between the a high-voltage wheel and "regular" wheel to see which is more efficient.

[chrisjunlee]

21 minutes ago, Marty Backe said:

I think there are other potential benefits. Efficiency (longer range), acceleration, etc. 

There is a subtle downside, and I say subtle, because I'm sure this is going to be completely overlooked by the EUC 'engineers': arcing short circuiting. 

For higher voltage, you need to increase the distance between components and traces. 

But chances are, we don't need to worry about it at this point, since the dielectric breakdown of dry air is 3000 V/mm, and we're barely going from 84v to 126v. 
 

[houseofjob]

3 minutes ago, chrisjunlee said:

There is a subtle downside, and I say subtle, because I'm sure this is going to be completely overlooked by the EUC 'engineers': arcing short circuiting. 

For higher voltage, you need to increase the distance between components and traces. 

But chances are, we don't need to worry about it at this point, since the dielectric breakdown of dry air is 3000 V/mm, and we're barely going from 84v to 126v. 

[chrisjunlee]

3 minutes ago, Marty Backe said:

We don't have any emperical evidence regarding range (yet), but generally, higher voltage wheels equates to everything being better.

I believe it, but would love to understand the physics of it and work out the equations.

Outside DC motors, there are cases where low voltage seems to be the way to go. For instance, CPUs and graphics cards are low voltage. I think it has to do with preventing quantum tunneling or spark gap jumps.

[Marty Backe]

1 minute ago, chrisjunlee said:

I believe it, but would love to understand the physics of it and work out the equations.

Outside DC motors, there are cases where low voltage seems to be the way to go. For instance, CPUs and graphics cards are low voltage. I think it has to do with preventing quantum tunneling or spark gap jumps.

Exactly. These are high density systems. The EUC control boards are still a 5-volt system. But we're talking about the power electronics component.

[chrisjunlee]

1 minute ago, houseofjob said:

I laughed so hard LMAO XD

If you want to go next level wtf, google for "tin whiskers NASA". NASA since they're one of the few that requires space grade reliability (lasting hundred years). The switch to lead-free solder has made tin whiskers a failure point we need to worry about. And they grow spontaneously - it's not a matter of time, they can grow at day 1 off the factory floor or year 10. They even grow through conformal coatings, so not even mil-spec is prepared for it 😬.

[houseofjob]

41 minutes ago, chrisjunlee said:

I laughed so hard LMAO XD

If you want to go next level wtf, google for "tin whiskers NASA". NASA since they're one of the few that requires space grade reliability (lasting hundred years). The switch to lead-free solder has made tin whiskers a failure point we need to worry about. And they grow spontaneously - it's not a matter of time, they can grow at day 1 off the factory floor or year 10. They even grow through conformal coatings, so not even mil-spec is prepared for it 😬.

That's it! Tin Whiskers shall be my next band name 

Edited August 3, 2019 by houseofjob

[Darrell Wesh]

Top speed: Don’t worry about it 

No 80% alarm, what’s the point, you won’t ever reach it 😄

[esaj]

13 minutes ago, Darrell Wesh said:

Top speed: Don’t worry about it 

No 80% alarm, what’s the point, you won’t ever reach it 😄

Slightly off-topic, but wasn't it revealed some time ago that GW's never had any "80%" alarm, just the typical speed- & battery-percentage based alarm that starts to go down once the battery is depleted enough? Can't find the topic right now, but there was a picture with different models, voltages and speed-limits...

Edit: Here it is:

 

Official values directly from Gotway:

 

 

Don't know where the "80%" -thing originated.

Edited August 3, 2019 by esaj

[houseofjob]

6 minutes ago, Darrell Wesh said:

Top speed: Don’t worry about it 

No 80% alarm, what’s the point, you won’t ever reach it 😄

Only in EUC😄

We don't all buy a 100mph+ car and say "no, that's too fast and dangerous, make it less".... cuz it doesn't mean you Must go the 100mph+ max!

[meepmeepmayer]

1 hour ago, Lucas Alexander Oliver said:

I am a layman when talking terms like voltage, amps amp hrs. All that. I think  In regular terms like. Range acceleration top speed.  Does a higher voltage system make all these values better ? 

In theory it's a balancing act between

• Higher top speed along with a bit of better efficiency at high voltage.
• Better acceleration at high current, which implies a low voltage.

Range is the same (ignoring possible efficiency differences which seem to be small).

In practice, I guess we'll find out. With the Nikola it just looks like the 100V can go faster and the rest is the same. So higher voltage is better? Not sure.

[meepmeepmayer]

5 minutes ago, esaj said:

Slightly off-topic, but wasn't it revealed some time ago that GW's never had any "80%" alarm, just the typical speed- & battery-percentage based alarm that starts to go down once the battery is depleted enough?

Might be 80% of the motor top (no torque) speed or something like this. Strictly voltage dependent. @Chriull had a nice post where he did some math with these numbers, I can't find it.

[UniVehje]

126v is kind of exiting news but I’m seeing a lot of uncertainty here. How come there are still no good explanations about this? It’s all just guesses and theories. 

Seems like there are no serious downsides on higher voltages and one confirmed upside (higher top speed). And then there’s the Z10 doing fine with very low voltage. I’m still not seeing anything that exites me on these 100 and 126 wheels as I’m already going as fast as I want. 

But I'm glad to see this development. We’ll soon learn more and Gotway is moving the industry forward. 👍

Edited August 3, 2019 by UniVehje

[houseofjob]

12 minutes ago, meepmeepmayer said:

Range is the same (ignoring possible efficiency differences which seem to be small).

FWIW, the riders in NYC averaging higher speeds on their 100V claim the equivalent range is better then their previous 84V version wheels going around similar average speeds, but less range when riding their 100V averaging slower speeds (like when we have group rides where some of the riders ride slower, bringing the group speed down).

[Planemo]

1 hour ago, Marty Backe said:

 but generally, higher voltage wheels equates to everything being better.

I would agree with that - less current = less heat which is the bane of all electronics. This jump to 126v from (for example) my lowly 58v could mean substantially less heat in the system and less weight due to much thinner conductors. That said, what I don't understand is how the Z10, with one of the lowest (if not THE lowest) voltage out there can still deliver some fairly serious amp peaks without even so much as a fan on the board. I know they run 14 mosfets but that cant be the only answer?

I don't want to derail the thread away from the subject, but the 126v Vs 58v got me thinking due to how differently the wheels must handle everything, and what that could mean for the future. Will there be an upper limit?! As has been said, above 60v could get serious so where will Gotway draw the line I wonder. And will 126v offer anything substantial over and above 100v given that an EUC is still an EUC? Surely theres only so much we need - we're not going from a small electric car to an electric articulated truck! 

[houseofjob]

10 minutes ago, meepmeepmayer said:

I can't find it.

LOL, I feel like it would be so awesome if there was another site indexing and cataloging all the more important EUC forum posts, like how I save and folder stuff on Facebook that I know I'll wanna pull up in later discussions.

[houseofjob]

7 minutes ago, Planemo said:

That said, what I don't understand is how the Z10, with one of the lowest (if not THE lowest) voltage out there can still deliver some fairly serious amp peaks without even so much as a fan on the board. I know they run 14 mosfets but that cant be the only answer?

The whole underbelly of the Z is a ginormous heatsink, like twice the size of these board heatsinks KS & Gotway use, which I believe is partly why the Z is so much heavier than other wheels with similar battery pack sizes.

Edited August 3, 2019 by houseofjob

[Rywokast]

ok so whos gonna be the first person to wipe out going 80 kmph on an EUC 

[Planemo]

10 minutes ago, houseofjob said:

The whole underbelly of the Z is a ginormous heatsink, like twice the size of these board heatsinks KS & Gotway use, which I believe is partly why the Z is so much heavier than other wheels with similar battery pack sizes.

If you are referring to the motor/hub as the underbelly, I do appreciate that, but all the current passes through the board before it even hits the wheel, which is thermodynamically insulated from the board. In other words, I can understand how the motor could control it's heat, but not the board/s.

[houseofjob]

13 minutes ago, Planemo said:

If you are referring to the motor/hub as the underbelly, I do appreciate that, but all the current passes through the board before it even hits the wheel, which is thermodynamically insulated from the board. In other words, I can understand how the motor could control it's heat, but not the board/s.

No, this is on the underside of the shell itself, attaching to the board.

[esaj]

Another thing that came to mind is (if they're using the same motor), how much power can the motor handle continuously? With higher voltage, you use less current to produce the same power vs. a lower voltage. If the motor can handle the same duty cycles with higher voltage as it did with lower voltage, that means more total output power. If not, and they have to limit the power (average current, lower duty cycle) to keep the motor heating in check, it means that they're trading higher top speed for less torque (less current) for the same output power.

Edited August 3, 2019 by esaj