What’s the point of higher voltage? (Split from “Sherman-S 3600wh: 100V, 20", suspension, 97lb”)

[Boris Lämpel]

You are all the time discussing about the feeling of different voltages. But let's talk about the real advantages.

If we would take a battery with a fix amount of cells. Would there be any difference of the capacity or safety? With lower voltage we have more cells in parallel. Does it mean it is safer because of less voltage sag?

[Planemo]

15 minutes ago, Boris Lämpel said:

With lower voltage we have more cells in parallel. Does it mean it is safer because of less voltage sag?

Not necessarily because a higher voltage can use less current, therefore less chance of sag and therefore less parallels needed. Its a balance that the manufacturers dance around.

[Freeforester]

On 3/15/2023 at 4:01 PM, Bustapalapno said:

I meant lagging behind in terms of status in the industry

It could be argued that ‘status in the industry’ may be awarded or otherwise accrued by other factors, such as eg reliability of machines, aesthetic considerations, getting a 100v wheel to deliver performance very close to 134v, or even built-in safety features. Only the individual rider can themselves decide how much they “need” the ‘ultimate’ (but only until next month in the case of Begode offerings) speed machine (not even an EUC, as already discussed) over the other various factors.  

Edited March 18, 2023 by Freeforester

[soulson]

47 minutes ago, Planemo said:

higher voltage can use less current, therefore less chance of sag

This is true for equivalent power output. But the battery with more cells in series will also have increased equivalent series resistance, which will increase voltage sag under load. It's too early for brain workey good so I don't want to try to guess which effect would be stronger right now

[Planemo]

I agree, but then we get into the fact that nearly all 21700 cells (low parallel/later wheels) have lower resistances than 18650's (high parallel/older wheels like OG Sherman) so the goalposts are moved on that front too. Even with brain workey good it's still a fair bit of maths juggling to make an educated decision 

 

[tudordewolf]

There's a constraint nobody has brought up yet, and that's the wires going into the motor. Higher voltages allow for the same power to be delivered with less current, which reduces ohmic heating and current losses.

From the battery's perspective, it doesn't matter whether they're series or parallel, just the C-rate you're draining them at. A 1kwh battery being drained of 1kw of power will experience the same load per cell and temperature rise whether it's wired for 84V or 120. The difference is that if they're both using XT60 connectors and have the same gauge motor wires, the 84V one will be wasting twice as much power as heat lost to resistance and generating twice as much waste heat, because the energy lost goes up with the square of the current. Doubling the voltage and halving the amperage cuts the waste lost through conductors by a factor of 4.

Edited March 18, 2023 by tudordewolf

[mrelwood]

13 hours ago, tudordewolf said:

There's a constraint nobody has brought up yet, and that's the wires going into the motor. Higher voltages allow for the same power to be delivered with less current, which reduces ohmic heating and current losses.

Well, it doesn’t end there though. If the motor would be identical like it has been on several Begode wheels for example, it would be driven with the same voltage at the same speed. Only if the Kv rating of the motor would be compensated for the higher voltage, would the driving voltage be higher and current lower.

To my understanding, how exactly the motors are tuned on each wheel model is not known very well, other than the ambiguous “HT” abbreviation, which in itself doesn’t tell us any specifics.

13 hours ago, tudordewolf said:

From the battery's perspective, it doesn't matter whether they're series or parallel, just the C-rate you're draining them at.

True. But lower voltage wheels have more batteries in parallel for the same Wh, so that the current draw per cell is lower.

 

 Comparing any single spec is extremely difficult because of all this. It’s like trying to compare whether garlic or pepper is a better spice. It all depends on so many factors.

[rcgldr]

9 hours ago, mrelwood said:

kV ... how exactly the motors are tuned on each wheel model is not known very well, other than the ambiguous “HT” abbreviation, which in itself doesn’t tell us any specifics.

Assuming the magnets are the same, then typically, more windings are used to generate stronger magnetic fields for more torque, but that lowers the kV (max speed) of a dc motor. Then again, King Song 16X and 18XL have the same claimed top speed (31 mph), but the 16X has more torque (for the same top speed, the 18XL could use more windings to get more motor torque to compensate for the 18 inch tire). The unknown is if both motors are using the same magnets.

9 hours ago, mrelwood said:

It’s like trying to compare whether garlic or pepper is a better spice. It all depends on so many factors.

Pepper is clearly better. With garlic, your body reeks of a foul odor the next day.

[Freeforester]

16 hours ago, rcgldr said:

Pepper is clearly better. With garlic, your body reeks of a foul odor the next day.

When in Transylvania,  this attribute of garlic may be beneficial. Or the west coast of Scotland when the midges are about.

[Planemo]

36 minutes ago, Freeforester said:

Or the west coast of Scotland when the midges are about.

Funnily enough I only heard about 'Highland Midges' after researching about getting bitten to pieces in Cyprus one summer. Never seen anything like it. Didn't know anything about midges prior, having lived South East England all my life. Those Cyprus midges totally destroyed me, turned a grown man to tears. I pretty much hermetically sealed the flat but the bastards were getting in through the aircon ventilation system. Couldn't believe something so small could cause a human so much damage. I just thought they were fruit flies or something. 100x worse than mozzies (which I also suffer with).

[JeremySPFF]

On 3/19/2023 at 12:35 AM, mrelwood said:

Comparing any single spec is extremely difficult because of all this. It’s like trying to compare whether garlic or pepper is a better spice. It all depends on so many factors.

Sorry, but I highly disagree with this. Both items are machines and are not subjective. There are some very easy ways to determine which wheels is faster or more powerful. It seems both the manufacturers and reviewers desperately want to keep data away from consumers, and instead tell us their opinions.

 

I appreciate all of the technical talk, but at the end of the day I am not an electrician and I barely understand what you mean. I think we should demand more data that is easy to understand. How much horsepower\torque does the wheel have? What is the 0-30 time? Why doesn't Tesla advertise their voltage if its so important? How can we look at these machines objectively and not subjectively?

[GoGeorgeGo]

On 3/15/2023 at 1:20 PM, MrMonoWheel said:

How tf are you guys leaning so hard that you can tell a Sherman S doesn't have the same power as a 134v wheel? Like EUCs work by balancing out whatever for you put into them, which means you would have to be right on the edge of overpowering the Sherman S to feel the difference with the higher power wheels, no?

So far I've never even heard my wheel beep from the riding I do. However the other day I finally got to try a V13, and I must say it's a powerful wheel, but acceleration wise I was still limited by my own skill level. 

Side note, now that I have had time on a V13 I can undoubtedly say I am extremely happy with my choice of Sherman S. There's no comparison, it's more compact, easier to maneuver, significantly smoother running, and just feels solid. The v13 build quality was nice but the wheel overall felt like a step back compared to the magnesium alloy Sherman S with proper fork style suspension.

it doesnt need to just be at peak power you notice a difference. The main advantage is being able to achieve higher speeds on a torque tuned motor.

voltage directly effects how fast an electric motor will spin. magnetic resistance is also a factor. larger magnets mean more resistance, so lower speed for the same power input, but more torque. smaller magnets mean less resistance, so more speed but less torque. 

by pumping higher voltages, your able to get the benefits of a c38-40 high torque motor, while also reaching speeds otherwise only attainable by c30 motors

[meepmeepmayer]

On 3/19/2023 at 5:35 AM, mrelwood said:

To my understanding, how exactly the motors are tuned on each wheel model is not known very well, other than the ambiguous “HT” abbreviation, which in itself doesn’t tell us any specifics.

You already got your answer, but I want to expand:

• More windings/magnets,
• stronger magnets,
• stronger windings (more copper per winding)

each gives more torque at the cost of a lowered max speed due to a higher back-EMF (lower Kv parameter). At least that's how I always understood it. It's all very visual, not much ambiguity in my book. More stuff that resists = it kills your max speed, but you can grab onto it for torque.

The HT/C38 motors literally have stronger (bigger) magnets (38mm wide) than the HS/C30 motors (30mm wide magnets). Probably more windings, too, I don't know, but you can count in the EcoDrift disassembly pictures if you want. I'm not sure if the motors are built differently in how much copper a winding gets.

(I'm still not an electrical engineer so I might be completely wrong.)

[Planemo]

14 hours ago, GoGeorgeGo said:

it doesnt need to just be at peak power you notice a difference. The main advantage is being able to achieve higher speeds on a torque tuned motor.

voltage directly effects how fast an electric motor will spin. magnetic resistance is also a factor. larger magnets mean more resistance, so lower speed for the same power input, but more torque. smaller magnets mean less resistance, so more speed but less torque. 

by pumping higher voltages, your able to get the benefits of a c38-40 high torque motor, while also reaching speeds otherwise only attainable by c30 motors

No one is disagreeing with any of that.

The point we have repeatedly tried to make is that if you're not beeping a low voltage wheel then you're in no position to say it's got less power (whatever the rpm) than a higher voltage wheel.

The only slight issue I have is your statement 'it doesnt need to just be at peak power you notice a difference' as this could be construed as suggesting that all high voltage and/or high torque wheels will be/feel quicker than low voltage and/or low torque wheels but this isn't true.

A further example to get at what we are saying is that I would wager someone like Kuji on an OG Sherman could out-accelerate most riders on high voltage and/or high torque wheels. All because the vast majority of riders don't have the necessary skill/kahunas to access the power they already have and simply going up on voltage/torque won't generally change that. I say generally because I accept that having a higher voltage/torque wheel might give a rider the re-assurance they need to be able to push a little harder but that certainly doesn't mean the low voltage wheel you already had couldn't keep up if you wanted it to.

[mrelwood]

19 hours ago, JeremySPFF said:

There are some very easy ways to determine which wheels is faster or more powerful.

Absolutely! A reinforced treadmill and a few force metering devices. Yet I haven’t seen the force vectors being measured like this on any wheel. I think Ecodrift or someone used to have such a system in place years ago though.

19 hours ago, JeremySPFF said:

It seems both the manufacturers and reviewers desperately want to keep data away from consumers, and instead tell us their opinions.

The reviewers don’t have any data that they are hiding. Manufacturers do though, like they do in any area of manufacturing. But they are generally useless to the rider.

19 hours ago, JeremySPFF said:

I think we should demand more data that is easy to understand.

That’s a problem though, since the performance data of an electric self-balancing vehicle is nothing like that of a car or a motorcycle. It just isn’t easy to understand or to relate to a real world riding situation.

19 hours ago, JeremySPFF said:

How much horsepower\torque does the wheel have?

Varies depending on the battery level, riding speed, and ambient temperature.

19 hours ago, JeremySPFF said:

What is the 0-30 time?

Depends mostly on the rider’s weight and them cojones, as well as the power delivery curve and other factors mentioned above.

19 hours ago, JeremySPFF said:

Why doesn't Tesla advertise their voltage if its so important?

Exactly. It isn’t, as it can be compensated for by other means.

19 hours ago, JeremySPFF said:

How can we look at these machines objectively and not subjectively?

Why would we though? We already know that basically all performance wheels released in the last 2-3 years can accelerate to 50km/h at at least around 3-3.5 seconds with a 70kg rider. And for wheels that don’t have a limited top speed, each rider can measure the free spin speed and determine their own personal safety headroom target.

But how often do you try to accelerate as fast as the wheel is capable of, just at the verge of an overlean? The wheels are already powerful enough for riders not having to ever think about it unless they are deliberately racing. Just like I would expect that you aren’t / wouldn’t be testing the 0-60mph acceleration of your car during your daily commute. Or even ever pressing the gas pedal down all the way.

 

16 hours ago, meepmeepmayer said:

• More windings/magnets,
• stronger magnets,
• stronger windings (more copper per winding)

each gives more torque at the cost of a lowered max speed due to a higher back-EMF (lower Kv parameter).

I think you are correct. But more windings requires a thinner wire for the coils to fit, which in turn (heh!) decreases the torque and increases the overall resistance.

 So yes, we know in which direction any single parameter affects the performance. But any single parameter usually can’t be changed on its own, and unless we calculate the exact changes of each parameter, we simply don’t know the end result. And for that we would have to disassemble the motor so we can measure at least the thickness and number of the wires, number of wraps, and the strength of the magnetic field. And that’s only for the motor, for 100V vs 134V comparison we’d also have to test (and probably fry) both controllers, and consider the battery pack setups as well.

 But again, none of that would affect our daily rides in any way, so what would be the point?

 

I usually quote only the parts that I want to discuss further or disagree with, but @Planemo made me disregard all that. I fully agree with everything he said below, and I think he put it all into words very well:

2 hours ago, Planemo said:

The point we have repeatedly tried to make is that if you're not beeping a low voltage wheel then you're in no position to say it's got less power (whatever the rpm) than a higher voltage wheel.

The only slight issue I have is your statement 'it doesnt need to just be at peak power you notice a difference' as this could be construed as suggesting that all high voltage and/or high torque wheels will be/feel quicker than low voltage and/or low torque wheels but this isn't true.

A further example to get at what we are saying is that I would wager someone like Kuji on an OG Sherman could out-accelerate most riders on high voltage and/or high torque wheels. All because the vast majority of riders don't have the necessary skill/kahunas to access the power they already have and simply going up on voltage/torque won't generally change that. I say generally because I accept that having a higher voltage/torque wheel might give a rider the re-assurance they need to be able to push a little harder but that certainly doesn't mean the low voltage wheel you already had couldn't keep up if you wanted it to.

 

[JeremySPFF]

2 hours ago, mrelwood said:

Just like I would expect that you aren’t / wouldn’t be testing the 0-60mph acceleration of your car during your daily commute. Or even ever pressing the gas pedal down all the way.

Good Points on all the others, but I hit those electrons from 0-60 almost every light. haha. Most people with performance cars that are serious do like to test them at the track.

[soulson]

3 hours ago, mrelwood said:

the performance data of an electric self-balancing vehicle is nothing like that of a car or a motorcycle. It just isn’t easy to understand or to relate to a real world riding situation.

The primary thing I've learned from hanging out on this forum is that a lot of people do not have a solid understanding of how the EUCs they ride actually work 

[GoGeorgeGo]

7 hours ago, Planemo said:

No one is disagreeing with any of that.

The point we have repeatedly tried to make is that if you're not beeping a low voltage wheel then you're in no position to say it's got less power (whatever the rpm) than a higher voltage wheel.

The only slight issue I have is your statement 'it doesnt need to just be at peak power you notice a difference' as this could be construed as suggesting that all high voltage and/or high torque wheels will be/feel quicker than low voltage and/or low torque wheels but this isn't true.

A further example to get at what we are saying is that I would wager someone like Kuji on an OG Sherman could out-accelerate most riders on high voltage and/or high torque wheels. All because the vast majority of riders don't have the necessary skill/kahunas to access the power they already have and simply going up on voltage/torque won't generally change that. I say generally because I accept that having a higher voltage/torque wheel might give a rider the re-assurance they need to be able to push a little harder but that certainly doesn't mean the low voltage wheel you already had couldn't keep up if you wanted it to.

coming from an ex20 hs, i absolutely disagree. i never rode the beeps and yet i overtorqued that wheel several times at low speeds. and im certainly no kuji. 

my friend had the torque version and was constantly riding beeps to keep up.

the ex30 has the same speeds as my ex20hs but has way more torque than the ex20ht

[JeremySPFF]

12 minutes ago, GoGeorgeGo said:

the ex30 has the same speeds as my ex20hs but has way more torque than the ex20ht

Would you mind doing an acceleration test for your channel for both the wheels? I would like and subscribe if you did

[GoGeorgeGo]

16 minutes ago, JeremySPFF said:

Would you mind doing an acceleration test for your channel for both the wheels? I would like and subscribe if you did

sold the ex20 to buy the ex30

[meepmeepmayer]

4 hours ago, mrelwood said:

I think you are correct. But more windings requires a thinner wire for the coils to fit, which in turn (heh!) decreases the torque and increases the overall resistance.

I thought "windings" were the coils made from the wires, one corresponding to each magnet (or some other fixed ratio). So you can still have more or less metal per winding, and more or less space between windings. Maybe I'm wrong about the terminology. I meant the number of coils (is there a better word?).

Anyways, in practice the manufacturers seem to order a standard motor, but the number of magnets and their width seems to be customizable. They will know more or less what properties they get from such a motor (maybe less, given how the first C40 seems to have been a bust). I don't think it's an exact science for them either.

[mrelwood]

5 hours ago, GoGeorgeGo said:

coming from an ex20 hs, i absolutely disagree. i never rode the beeps and yet i overtorqued that wheel several times at low speeds.

He did say “at any RPM”, meaning at any speed. The point he was making was that if you wouldn’t have overtorqued the EX20, you wouldn’t be able to compare the peak power to other wheels. You need to reach the torque limit to know where the torque limit is. You can’t feel the torque limit by strolling around with medium acceleration.

 

5 hours ago, soulson said:

a lot of people do not have a solid understanding of how the EUCs they ride actually work 

You are absolutely right. And that has been and will continue being the cause for a lot of overleans. They often find interest in learning the specifics while licking their wounds from their first overlean crash.

Edited March 21, 2023 by mrelwood

[GoGeorgeGo]

2 hours ago, mrelwood said:

He did say “at any RPM”, meaning at any speed. The point he was making was that if you wouldn’t have overtorqued the EX20, you wouldn’t be able to compare the peak power to other wheels. You need to reach the torque limit to know where the torque limit is. You can’t feel the torque limit by strolling around with medium acceleration.

 

You are absolutely right. And that has been and will continue being the cause for a lot of overleans. They often find interest in learning the specifics while licking their wounds from their first overlean crash.

i just disagree with the thinking that you need to be some racing extremist rider to find the limits of your wheel. its not really difficult for larger people to over torque wheels, and except for a few High Speed 100v wheels most wheels are slow enough for everyone to overlean. 

what 100v wheels go 40 mph without beeps? monster pro, shermanS,shermax, ex20hs, rshs, exnhs? a bunch of low torque wheels only owned by enthusiast riders who are not strolling around at 20 mph. 

[mrelwood]

38 minutes ago, GoGeorgeGo said:

i just disagree with the thinking that you need to be some racing extremist rider to find the limits of your wheel.

It’s not about that. It’s not about the speed. I’m sure you agree that all wheels can be overleaned well before their top speed. And once you do, you have found out the torque level of that wheel (at that specific speed and other conditions). Then you can compare the max torque to other wheels that you have also overleaned. Regardless of speed, or whether you’re racing or an extremist.

 This whole fight started when people claimed that they feel the power differences of various wheels immediately, at all levels of acceleration and speed. And that’s what we are trying to explain that it’s not possible.

[Planemo]

18 hours ago, GoGeorgeGo said:

coming from an ex20 hs, i absolutely disagree. i never rode the beeps and yet i overtorqued that wheel several times at low speeds. and im certainly no kuji.

I'm not saying that beeps always come before an overtorque. In fact I lumped both beeps AND overtorque together earlier in this thread when explaining the point but ended up leaving the word overtorque out in my later posts as it was just getting repetitive and I assumed most folks would understand what I meant anyway. To avoid any confusion, when I say that someone can't tell how powerful a wheel is until it beeps, I also mean and/or overtorque.

And FWIW I over torqued my Sherman at low speed too. Other than that one occasion I never rode the beeps or overtorqued it, so as far as I am concerned I don't need a higher voltage and or higher torque wheel. And I maintain that even if I did get one, that extra voltage/torque wouldn't be noticeable.

18 hours ago, GoGeorgeGo said:

my friend had the torque version and was constantly riding beeps to keep up.

Then yes he is a candidate for a wheel with more voltage and/or torque. Not sure what your point is.

18 hours ago, GoGeorgeGo said:

the ex30 has the same speeds as my ex20hs but has way more torque than the ex20ht

Again not sure what your point is.