Begode EX20S 3600wh: 100V, suspension, 104lb

[GoGeorgeGo]

9 hours ago, supercurio said:

Sorry to contradict but I will clarify.

Let's say that in order to brake from 30 to 20 mph in 3 seconds, you need to dissipate 1500W during these 3 seconds, and that regen braking efficiency is 40% (fantasy numbers)

So the energy which will be sent back to the pack will be 600W during these 3 seconds.

• A 32s6p configuration at 4V per cell is 128V.
  At 128V, 600W is 4.6875 A of current.
  Divided per 6: 0.78125 A per cell.
  600W into 192 cells is 3.125W per cell
• A 24s8p configuration at 4V per cell is 96V.
  At 96V, 600W is 6.25 A of current.
  Divided per 8: 0.78125 A per cell (same)
  600W into 192 cells is still 3.125W per cell

Conclusion:
Packs configured in 32s6p and 24s8p both have the same capacity, power, torque, acceleration, stress resistance, sag characteristics, braking capability.
Simply because they're both 192 cells, and as a pack will be formed of less parallels since it has more series, the controller will take/regen less current due to the higher voltage accordingly.

But that is assuming an exact equal dispersion of power over every single cell instantaneously which is not true. They sit in a circuit and as such the first cell in series theoretically is charging and discharging fractions of a second before the last cell in series. If electricity perfectly dissipated perfectly instantly the cells would never come out of balance in the first place. Granted im sure the different cells also have ever so slightly different resistance levels also which contributes to imbalance problems. But surely spreading a current over 8 parallels will reduce the load on the first sets of cells ever so slightly compared to spreading it into 6 parallels. Its only slight each time but charge after charge after discharge the problem compounds if your not balancing the cells routinely

[Chriull]

2 hours ago, GoGeorgeGo said:

But that is assuming an exact equal dispersion of power over every single cell instantaneously which is not true. They sit in a circuit and as such the first cell in series theoretically is charging and discharging fractions of a second before the last cell in series.

For such cases and most others impact of current is instantenous for the whole circuit.

There is no need or sense to look at high frequency waves or wavefronts.

Serial cells can be assumed to be charged and discharged in the exact same point of time - any relativistic, quantum theoretic and ultra high frequency influences can be safely neglected. 

Additionally such effects would make no difference in regard to the equivalence of 32s6p vs 24s8p for regen breaking.

2 hours ago, GoGeorgeGo said:

If electricity perfectly dissipated perfectly instantly the cells would never come out of balance in the first place. Granted im sure the different cells also have ever so slightly different resistance levels also which contributes to imbalance problems.

Such slight differences in resistance, capacitance, different temperatures and other parameters changing differently over the cells lifetime are exactly the reason for cell imbalances!

During charging, burdening and regen braking.

[supercurio]

@GoGeorgeGo yes imbalance would mostly develop due to difference in internal resistance between cells, so some of the energy is lost in heat both while charging and discharging (current squared), which makes cells drift apart gradually.

High drain/regen loads tends to make imbalances happen quicker, as well as low temperature discharge apparently - which also increases internal resistance.

Likewise, in some packs you have BMS electronics heating up some cells and not others and just from that, imbalance can be multiplied.

Edited April 12, 2022 by supercurio

[meepmeepmayer]

@supercurioLast attempt at explaining what I mean, to not derail this thread any further indeed

Maybe it helps to define a "performance" wheel as a wheel where the motor is the weakest link. And if the battery is the weakest link the wheel could perform better by adding more battery (more p's) and thus does not count as performance wheel. For example, going from a 1800Wh (4p) Nikola to a 2700Wh (6p) Nikola just gives you more range. Whereas the S18, as I understood it, seems to be a little underpowered compared to what a 4p variant of this hardware could be. (That does not speak against the S18, it is what it was designed to be.)

That's why I'm saying there seems (or seemed, with the shitty 7.5A cells) to be a cutoff between 3p and 4p. And that argument is independent of voltage or ultimate power output or comparing different wheels or anything else. If the EX20S were 3p or the Master were 3p the argument would still stand. If you run out of 3*7.5A, you run out, no matter anything else.

I could still be entirely wrong about this 3p vs. 4p cutoff, but that's another question.

Anyways, peak power output, peak voltage, peak current - all three matter (on paper, and sometimes even in real life), even if the first is just the product of the others.

-

So much for that. When do you guys think the first EX20s's will be in people's hands?

Edited April 12, 2022 by meepmeepmayer

[TantasStarke]

41 minutes ago, meepmeepmayer said:

@supercurioLast attempt at explaining what I mean, to not derail this thread any further indeed

Maybe it helps to define a "performance" wheel as a wheel where the motor is the weakest link. And if the battery is the weakest link the wheel could perform better by adding more battery (more p's) and thus does not count as performance wheel. For example, going from a 1800Wh (4p) Nikola to a 2700Wh (6p) Nikola just gives you more range. Whereas the S18, as I understood it, seems to be a little underpowered compared to what a 4p variant of this hardware could be. (That does not speak against the S18, it is what it was designed to be.)

That's why I'm saying there seems (or seemed, with the shitty 7.5A cells) to be a cutoff between 3p and 4p. And that argument is independent of voltage or ultimate power output or comparing different wheels or anything else. If the EX20S were 3p or the Master were 3p the argument would still stand. If you run out of 3*7.5A, you run out, no matter anything else.

I could still be entirely wrong about this 3p vs. 4p cutoff, but that's another question.

Anyways, peak power output, peak voltage, peak current - all three matter (on paper, and sometimes even in real life), even if the first is just the product of the others.

-

So much for that. When do you guys think the first EX20s's will be in people's hands?

I agree with the sentiment, I think the Master on the 50E setup will be throttled by the batteries, especially if it goes 55-60mph like I think. On a full charge those batteries could only sustain 40A or a little over 5000W for the motor. Vs the 40T setup that's over 100A and like 18000W that could theoretically (if the board and motor could handle it) be given.

I think someone said the EX20S HS are shipping out soon from the factory but I could be misremembering

[meepmeepmayer]

23 minutes ago, TantasStarke said:

I agree with the sentiment, I think the Master on the 50E setup will be throttled by the batteries, especially if it goes 55-60mph like I think.

Master is 4p so I expect NO problem there. Just like the other 4p wheels with the same cells. Even 40A (and that is just continuous) is a LOT.

ewheels is listing a 1920Wh Master with higher discharge cells though.

23 minutes ago, TantasStarke said:

I think someone said the EX20S HS are shipping out soon from the factory but I could be misremembering

I'm really curious about the suspension and what people will say about it. It looks quite different to the Master suspension. Bigger.

[TantasStarke]

37 minutes ago, meepmeepmayer said:

Master is 4p so I expect NO problem there. Just like the other 4p wheels with the same cells. Even 40A (and that is just continuous) is a LOT.

ewheels is listing a 1920Wh Master with higher discharge cells though.

I'm really curious about the suspension and what people will say about it. It looks quite different to the Master suspension. Bigger.

I don't think 4p will be enough for something that can go that fast, what's the peak current rating on the 50E cells? Assuming the EUC World estimation is correct/close to correct, my Nikola AR+ peaks up above 90A sometimes. On a 40A sustained pack peaking at over double is quite high, and would either degrade the cells with Begode letting it do it, or they'd tone it down to not do so. While the 4P 50E might be able to get very similar if not the same performance as the other options, I'm fairly sure the others will be a lot safer in the end, but it depends on how the Master behaves.

I think the EX20S is using the Hero suspension, but also not 100% on that

[BleepBloopBlop]

For what it is worth your AR+ has a higher KV motor than the C38 used in the master. Think of KV like the gearing of a bicycle. Since the C38 has a lower KV it's like being in a lower gear and reduces amp draw for a given motor output force. The 50E cells are rated at 14.7 amps peak in a non continuous discharge situation without cell degradation. They can easily discharge at higher rates for short durations without much cell degradation. The key with cells is to keep them under 80C temperature. If you look at the discharge over time curves you can see that it takes 10 minutes for the 50E to hit its temp limit at 15 amps. It takes nearly 6 minutes at 20 amps. Short burst at 25 amps aren't going to be an issue for these cells. The thing you will see is a good amount of voltage sag which impacts top speed. Unless you are trying to go 55mph with a good safety margin I don't see the need for the high discharge cells for 99% of use cases on the master.

  

[mike_bike_kite]

With modern car design they soften all the edges to try and reduce damage to pedestrians in an accident. Have you ever wondered where all those sharp edges have gone? I present the EX20S. I'm surprised they don't sharpen the pedal edges and stick a spike on the front !  

[onkeldanuel]

May be that this wheel rides well, but its just the ugliest wheel in euc history by far, its the Fiat multipla of euc  

[EMA]

nice wheel 

[meepmeepmayer]

Wow, there is virtually no plastic on this wheel. All metal. This is why it is so heavy. Does looks very nice, though Very similar build to the Master - robust and with minimal number of parts.

It has the same battery connector board like on the Master. I wonder if the packs are in parallel, or are 25.2V packs. It should be trivial to make a 134V EX20S with this build, I don't understand why it is still 100V.

I wish they would build the battery packs in a parallelogram shape for better ground clearance. It would hardly be more complex to build. Like this:

Edited April 27, 2022 by meepmeepmayer

[supercurio]

51 minutes ago, meepmeepmayer said:

It has the same battery connector board like on the Master. I wonder if the packs are in parallel, or are 25.2V packs. It should be trivial to make a 134V EX20S with this build, I don't understand why it is still 100V.

It uses a similar concept of battery connector board but the implementation is different.

I can confirm that the packs are the existing, well known and infamous 900 Wh 100.8V packs, and there are 4 of them in parallel, like on Monster Pro or Commander.
However they're in these metal boxes with foam padding on the inside which gives them a fair amount of protection

[meepmeepmayer]

31 minutes ago, supercurio said:

I can confirm that the packs are the existing, well known and infamous 900 Wh 100.8V packs, and there are 4 of them in parallel, like on Monster Pro or Commander.

Not surprising. Thanks for the confirmation.

They could easily do 4x 8s6p in series to get a 134V EX20S, though. If that kind of setup is good enough for the Master...

Anyways, they aren't doing it (for now), so I'm going to shut up about a 134V variant now

36 minutes ago, supercurio said:

However they're in these metal boxes with foam padding on the inside which gives them a fair amount of protection

That is great!

[meepmeepmayer]

Question:

Are the red and black cables in the middle of the battery connector board the power cables going to the board? They look a little thin. And unlike everything else, they are not meticulously fiberglassed.

Or is the power cable somewhere else?

[Nick McCutcheon]

Looks like there's a fuse built into the battery connector/charging PCB! Hopefully it's not too high valued such that it doesn't offer any protection 😅

[RagingGrandpa]

1 hour ago, meepmeepmayer said:

Are the red and black cables in the middle of the battery connector board the power cables going to the board? They look a little thin.

Yes, those are for the controller... with the same old wire sizes and XT60 connector that the 2021-era Gotways all use. 

I think they look small only because they're being dwarfed by the nearby XT90i's for the packs. But fine.
 

17 minutes ago, Nick McCutcheon said:

Looks like there's a fuse

Yup. A mini-ANL fuse, soldered down... not as nice as a bolted holder, but better than dangling in a wire harness I suppose.

Apparently there is no standard coloring for ANL fuse ratings, but from the video my guess is: 100A rating. A little oversized, but not 2x at least

Edited April 27, 2022 by RagingGrandpa

[meepmeepmayer]

1 hour ago, RagingGrandpa said:

Yes, those are for the controller... with the same old wire sizes and XT60 connector that the 2021-era Gotways all use. 

I think they look small only because they're being dwarfed by the nearby XT90i's for the packs. But fine.

Confirmed, it's a Gotway!

• If they had at least sleeved these board power cables. Do they literally not understand that the power for their (beautifully sleeved) motor cables comes from somewhere? I don't get it
• One smaller connector to carry 4x the current that each bigger connector carries. Classic Gotway move

[Tawpie]

Anddddd, if the wires were properly sized in the first place, they wouldn't get hot enough to need fiberglas sleeving (and you wouldn't suffer the losses). The sleeving is nice for abrasion protection I guess, but if they were properly...

[meepmeepmayer]

1 hour ago, Tawpie said:

but if they were properly...

Yeah, that is the motto for our Chinese EUCs in general and Begode/Gotway in particular. I know. Understanding the ununderstandable, trying to find a point in the pointless, etc.

[techyiam]

5 hours ago, Tawpie said:

Anddddd, if the wires were properly sized in the first place, they wouldn't get hot enough to need fiberglas sleeving (and you wouldn't suffer the losses). The sleeving is nice for abrasion protection I guess, but if they were properly...

Now that we have hollow bore motors, has anyone replaced all the under sized wires with proper guage ones to see whether there are benefits to be had?

 

 

 

 

Edited April 28, 2022 by techyiam

[Jean eRide.ie Community]

Just received my EX20S today. 

Put 200psi on suspension with a bit slower rebound and 45psi on the tire. 

I had the Monster Pro before and used the S18 and V11 for 20-70km each without issues before, but 47kg with suspension (high pedals) is a whole different world, I feel as if I only had been riding an EUC for 30min, as a beginner, holding onto something to mount and finding it hard to turn due to fear of falling due to the heavy weight+high pedals, making it top heavy.
As everything it's about getting used to, but it's the hardest EUC to get used to I've experienced so far, I'll keep practicing on an empty parking. 

Am I alone? 

Maybe I need a lower shock+tire pressure to get used to it and increase it later (just tested, seems to work) 

Edited May 2, 2022 by Jean eRide.ie Community

[GoGeorgeGo]

9 hours ago, Jean eRide.ie Community said:

Just received my EX20S today. 

Put 200psi on suspension with a bit slower rebound and 45psi on the tire. 

I had the Monster Pro before and used the S18 and V11 for 20-70km each without issues before, but 47kg with suspension (high pedals) is a whole different world, I feel as if I only had been riding an EUC for 30min, as a beginner, holding onto something to mount and finding it hard to turn due to fear of falling due to the heavy weight+high pedals, making it top heavy.
As everything it's about getting used to, but it's the hardest EUC to get used to I've experienced so far, I'll keep practicing on an empty parking. 

Am I alone? 

Maybe I need a lower shock+tire pressure to get used to it and increase it later (just tested, seems to work) 

45 psi in the tire is super high, im pretty sure it says its only rated for like 34 psi on the side of it , i ride it around 32-34 psi

[EMA]

https://ecodrift.ru/2022/05/03/begodeex20s-vneshnij-vid/

[Jean eRide.ie Community]

6 hours ago, GoGeorgeGo said:

45 psi in the tire is super high, im pretty sure it says its only rated for like 34 psi on the side of it , i ride it around 32-34 psi

Interesting, I put 45psi based on being a similar weight as rider on this video: