126-Volt Nikola

[Marty Backe]

So I just received a somewhat cryptic (language barrier) comment on a recent Facebook posting that I made of this picture

It was from Gotway:

Quote

 Maybe battery 126v is better for u .i do not know .maybe u can have try

Of course I replied in the affirmative.

What do you guys make of this statement? Is 126-volts a valid battery configuration?

I'm kind of like, "Wow" 

[meepmeepmayer]

On 8/3/2019 at 6:57 PM, Marty Backe said:

Is 126-volts a valid battery configuration?

126V checks out as exactly 4.2V*30!

(84V is 20*4.2V and 100.8V is 24*4.2V.)

Also, the Nikola 84V battery packs are 60 cells each (3*20), but a 2*30 126V battery would also be 60 cells. It fits the designed battery space exactly! No capacity lost due to bad geometry! You could have a 1600Wh 126V Nikola or even a ~1940Wh 126V Nikola (30 extra cells on top - 60 won't fit). 2400Wh 126V Nikola.

On 8/3/2019 at 6:57 PM, Marty Backe said:

It was from Gotway

Now I'm really intrigued! Wow indeed!

Edited August 14, 2019 by meepmeepmayer

[Marty Backe]

1 minute ago, meepmeepmayer said:

126V checks out as exactly 4.2V*30!

(84V is 20*4.2V and 100.8V is 24*4.2V.)

Also, the Nikola 84V battery packs are 60 cells each (3*20), but a 2*30 126V battery would also be 60 cells. It fits the designed battery space exactly! No capacity lost due to bad geometry! You could have a 1600Wh 126V Nikola or even a ~1940Wh 126V Nikola (30 extra cells on top - 60 won't fit).

Now I'm really intrigued! Wow indeed!

Wow Wow.

I'm going to get a message off to see how I can get one ...

Thanks for the confirmation 

You gotta love Gotway for pushing boundaries 

[meepmeepmayer]

1 minute ago, Marty Backe said:

You gotta love Gotway for pushing boundaries 

I credit Kingsong with finally forcing them to do that with the 18L speed and the 18XL/16X 1600Wh battery.

[Marty Backe]

3 minutes ago, meepmeepmayer said:

I credit Kingsong with finally forcing them to do that with the 18L speed and the 18XL/16X 1600Wh battery.

It took forever for KingSong to finally move to 84-volts. How many years do you think it'll be before they get to 126-volts (considering 100-volts is still a mystery to them)? 

[The Fat Unicyclist]

13 minutes ago, meepmeepmayer said:

Also, the Nikola 84V battery packs are 60 cells each (3*20), but a 2*30 126V battery would also be 60 cells. It fits the designed battery space exactly!

But wouldn't dropping from 3P down to 2P reduce the overall amount of current available? Or force the same amount of current a lesser amount of wire?

[Marty Backe]

2 minutes ago, The Fat Unicyclist said:

But wouldn't dropping from 3P down to 2P reduce the overall amount of current available? Or force the same amount of current a lesser amount of wire?

As the voltage increases the current demands decrease, all else being equal.

[The Fat Unicyclist]

1 minute ago, Marty Backe said:

As the voltage increases the current demands decrease, all else being equal.

In that case, if nothing else it should stop you beeping!   

[Marty Backe]

OK, I've received additional confirmation from Gotway. They are indeed testing the 126-volt configuration as we speak!

I'm going to get one.

The EUC universe keeps getting better and better 

[meepmeepmayer]

If they use that same board in other wheels, they can have a 2400Wh 126V Monster. 1600Wh 126V MSX. All these sizes work just like 84V.

[esaj]

Hope they get the design right, as this requires even better components, higher clearances/creepages on the board etc. The voltages are even more lethal than before and if they keep this up, some regulatory body is going to start looking into the wheels. Don't know the "rules" that closely, but anything over 60V DC is already regarded highly dangerous and there are limitations to selling such devices to normal consumers.

Then again, electric cars use several hundred volts (400V DC or something in Teslas?). AFAIK, they don't even use mosfets anymore, but IGBTs, maybe that's the next step for wheels.

 

[esaj]

5 minutes ago, meepmeepmayer said:

If they use that same board in other wheels, they can have a 2400Wh 126V Monster. 1600Wh 126V MSX. All these sizes work just like 84V.

If you take X cells with Y amphours, you always get the same amount of watthours regardless of the configuration, for example 100 x 3Ah cells:

All in parallel: 3.6V nominal, 300Ah =>  1080Wh

All in series: 360V nominal, 3Ah => 1080Wh

And any combination in between (2S50P, 50S2P, 4S25P, 25S4P...)

[meepmeepmayer]

1 minute ago, esaj said:

you always get the same amount of watthours regardless of the configuration

Yes, but physically the wheels were designed for 60 cell packs. 3*20 works and 2*30 works exactly. Meanwhile, 2*24 has space left and 3*24 doesn't fit. Which is why the 100V wheels waste space = potential battery size = range. E.g. 1600Wh 84V MSX vs. 1230Wh 100V MSX or 2400Wh 84V Monster vs. 1845Wh 100V Monster.

My point is, 126V is a more logical step coming from 84V because no space is lost and everything just "works the same". Unlike the 100V wheels. Even the 100V Nikola wastes space on the sides (just like the 100V MSX and 100V Monster), they were just lucky with their oversized design and managed to cram 1845Wh instead of 1230Wh into it.

So "the sizes work" meant literal, physical size of the battery packs

[esaj]

1 minute ago, meepmeepmayer said:

Yes, but physically the wheels were designed for 60 cell packs. 3*20 works and 2*30 works exactly. Meanwhile, 2*24 has space left and 3*24 doesn't fit. Which is why the 100V wheels waste space = potential battery size = range. E.g. 1600Wh 84V MSX vs. 1230Wh 100V MSX or 2400Wh 84V Monster vs. 1845Wh 100V Monster.

My point is, 126V is a more logical step coming from 84V because no space is lost and everything just "works the same". Unlike the 100V wheels. Even the 100V Nikola wastes space on the sides (just like the 100V MSX and 100V Monster), they were just lucky with their oversized design and managed to cram 1845Wh instead of 1230Wh into it.

So "the sizes work" meant literal, physical size of the battery packs

Right, didn't consider it from that point of view, good point. Still, while progress is a nice thing, considering the f**k ups of pretty much every manufacturer in the long run, I have my doubts how good idea pushing the voltage up all the time is. I just hope nobody ends up electrocuting themselves.

[meepmeepmayer]

Just now, esaj said:

Right, didn't consider it from that point of view, good point.

Gotway knew from the beginning there would be a 100V Nikola. Still they decided to make it so only a 84V 60 cell pack would fit, but neither a 72 cell 100V pack or a 80 cell 84V pack. Despite the wheel having so much space inside, they could likely have made the battery space longer to accommodate these options (certainly the 72 cell). But they didn't I'm sure I whined about that somewhere.

That's why I was so excited about the "sizes" of 126V batteries, they fit the same spaces as 84V batteries.

(Side question: Ah = "capacity" and Wh = "size", right? Are there better words?)

[Marty Backe]

Meanwhile, I'm just damn excited about the performance possibilities of 126-volts   we can stop talking about battery minutia now

[meepmeepmayer]

Sure, let's talk about motor minutia!

@esaj @Chriull Does x% higher voltage mean x% higher top speed? If they use the same motor as in the 84V or 100V wheels, how fast will it go? You can predict that, right?

[esaj]

11 minutes ago, meepmeepmayer said:

(Side question: Ah = "capacity" and Wh = "size", right? Are there better words?)

It's a good question, and I have no definite answer... basically both could be thought of as capacity, but the other gives the charge capacity and the other the power capacity, or something along those lines? People are more accustomed to seeing amp hours, because things like tablets and cell-phones use single-cell batteries, so the voltage is always the same, so you can just as well measure amp hours. Same for cars (at least as long as they use nominal 12V lead-acid batteries, for electric cars you of course look at kilowatthours). But when you've got devices using different battery configurations between models (different voltages), the amphours are misleading, because a lower voltage wheel will have a higher nominal amp-hour capacity, and using watt-hours gives you the "reality".

Edited August 3, 2019 by esaj

[esaj]

11 minutes ago, meepmeepmayer said:

Sure, let's talk about motor minutia!

@esaj @Chriull Does x% higher voltage mean x% higher top speed? If they use the same motor as in the 84V or 100V wheels, how fast will it go? You can predict that, right?

AFAIK, for the exact same motor, and leaving out details like power losses at different currents due to internal losses (they increase in square, that is current to the second power times resistance), yes, I guess you could say that x% higher voltage gives x% higher speed, but in practice, the increase in speed won't likely be linear, but still faster at higher voltage. Of course at some point, the voltage will be high enough to cause a short circuit in the coils, as the wires adjacent to each other will "strike through" the lacquering or whatever it is the coil wiring is covered with and the entire thing shorts and likely melts... well, maybe not melt, the motor will just come to a sudden halt and you break your forehead on the pavement.

Edited August 3, 2019 by esaj

[Hatchet]

Pfft! Hey Gotway, call me when you offer at least a 1 million volt! Sheesh!

Edited August 3, 2019 by Hatchet

[meepmeepmayer]

11 minutes ago, esaj said:

yes, I guess you could say that x% higher voltage gives x% higher speed

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!

[UniVehje]

1 minute 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’m thinking the same. Great that they are experimenting and I’m sure some will need those speeds. But I’m wondering if there are other benefits also?

[Ben Kim]

Ha, my 100V wheels will be obsolete and I didn't even get them yet!  I do wonder how we Americans will be charging these wheels though on our 110V volt outlets?  Charger with a step-up built-in, or will we need to source our own step-ups to charge? 

With that said, I think the NYC guys will no longer be going on 40 MPH rides, but 50 MPH rides once these things get released; and here I am with a wheel that struggles with 30! 

[chrisjunlee]

1 hour ago, Marty Backe said:

OK, I've received additional confirmation from Gotway. They are indeed testing the 126-volt configuration as we speak!

I'm going to get one.

The EUC universe keeps getting better and better 

I'm thoroughly regretting my 16X now @_@ - thoroughly. 

[chrisjunlee]

6 minutes ago, Ben Kim said:

Ha, my 100V wheels will be obsolete and I didn't even get them yet!  I do wonder how we Americans will be charging these wheels though on our 110V volt outlets?  Charger with a step-up built-in, or will we need to source our own step-ups to charge? 

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.