Begode Master 134V 2400WH Suspension

[redfoxdude]

The crazy headroom is a big draw for me as well, but also for the probable lack of speed throttling down to low battery (when riding at my usual for-fun speeds). Really looking forward to a teardown, I want to see the linkage design. The EX20S looks like it would be a joy to work on - assuming/hoping the Master has a similar construction.

[Nick McCutcheon]

On 4/3/2022 at 10:50 PM, gon2fast said:

Not sure if this has been posted in this thread, but that is far faster than I would ever go. Very excited!

 

This has clearly been sped up, no Begode wheel has ever beeped that fast and other videos of Master testing show it beeps like every other Begode wheel. Plus, the camera shakes are a bit too erratic to be natural. It feels like whoever made this video is being purposefully deceptive...

Edited April 12, 2022 by Nick McCutcheon
y

[Grimm10]

Here's better angles

https://youtu.be/q3uLGYISiC4

 

Edited April 5, 2022 by Grimm10

[Forwardnbak]

2 hours ago, Nick McCutcheon said:

This has clearly been sped up, no Begode wheel has ever beeped that fast and other videos of Master testing show it beeps like ever other Begode wheel. Plus, the camera shakes are a bit too erratic to be natural. It feels like whoever made this video is being purposefully deceptive...

A few videos I’ve seen I’ve wondered the same thing. The gravity of the rider sometime is a giveaway the way their body bumps about. 
when I speed ramp my videos if you go to 110-120% it nearly looks natural but looks faster (depending on how fast original ride was) 

[That Guy]

To have a unicycle with a 50mph "safe" (not cut out) speed is an exciting idea. I am not sure how far you can ride with the peak output of the 3.5kW motor (at 50mph the motor should be near its nominal output) and the battery of only 2,400Wh. Voltage sagging and battery stress at this performance will inevitably lead to both, short range and, worse - risk of battery damage. Is it even possible to engineer together the desire for a super-fast high performing machine with a durable long-range battery?...

 

[TantasStarke]

59 minutes ago, That Guy said:

To have a unicycle with a 50mph "safe" (not cut out) speed is an exciting idea.

Can't the Monster Pro go up to 55? This is assuming the speedometer is correct but this guy got 55.9mph/90kmh on a Monster Pro. I'd say a 5-6mph (~8-10kmh)  buffer is pretty decent for safe (assuming this guy was on the redline about to cutout), but some people might desire more of a safety margin

 

[EMA]

Monster Pro need -8% speedometer correction, but yes it can reach 50mph/80kmh, should be similar to other speed wheels, maybe a bit more

EXN beeps around 47mph full battery

[Nekko 2]

 

 

...assuming Master suspension is the same as EX22 (just kidding), which it looks like it is as far as the shock absorber is concerned.

Edited April 7, 2022 by Nekko 2

[alcatraz]

That wheel is awesome. Lighter than a sherman, with a bit more headroom and suspension.

I might buy one like 2 years after people have been riding it. I don't want to be a test dummy. 

[techyiam]

19 minutes ago, alcatraz said:

I might buy one like 2 years after people have been riding it. I don't want to be a test dummy. 

I also don't want to be a Guinea pig risking limbs, lives, or homes either, but I doubt I would be able to hold out for two years.

Also, I think it is going to be complicated when the times come. Buying a two year old wheel is going to be hard to do.

[alcatraz]

7 hours ago, techyiam said:

Also, I think it is going to be complicated when the times come. Buying a two year old wheel is going to be hard to do.

Not for me. 

I'll take out a screwdriver. Look inside, clean, silicone gaps, dust off the control board. Look for burned connectors. I have a rider history. Weight, max speed, etc. I'll measure all the cell groups in the packs. Check for corrosion. I guess I'll have to learn about how to inspect the suspension.

[techyiam]

30 minutes ago, alcatraz said:

Not for me. 

I'll take out a screwdriver. Look inside, clean, silicone gaps, dust off the control board. Look for burned connectors. I have a rider history. Weight, max speed, etc. I'll measure all the cell groups in the packs. Check for corrosion. I guess I'll have to learn about how to inspect the suspension.

 Interesting. Kudos to you. That would be a sensible way to go.

[RamonatheCat]

42 minutes ago, alcatraz said:

Not for me. 

I'll take out a screwdriver. Look inside, clean, silicone gaps, dust off the control board. Look for burned connectors. I have a rider history. Weight, max speed, etc. I'll measure all the cell groups in the packs. Check for corrosion. I guess I'll have to learn about how to inspect the suspension.

I absolutely need to learn to do this - most of my wheels are used and at some point I figure things are going to break down inside. 

[BleepBloopBlop]

Got confirmation from my supplier that my wheel will ship in the next 10 days from China by sea to the US. Also to note all of these first round wheels shipping out are being delivered with Samsung 50E cells. The Samsung 40T cells packs will come later.  Also to note the standard color will be black for these. Expecting it by mid late July with how slow sea transport has been. Looking forward to adding it to my collection. Should be right at home with the V12 and EX-N.

Edited April 8, 2022 by BleepBloopBlop

[BleepBloopBlop]

Just heard from Begode 40T production starts next week!

 

I think I'm still going to get a 50E pack as I've been monitoring my average power usage on my V12 and it is around 1200w. I peak around 3000w typically on a ride and top it out at 43mph indicated most rides. From the logs going top speed isn't where I'm seeing my peak power draw. When comparing the voltage graphs at various voltages the 40T has an advantage over say 5A per cell but that is around 2500w at peak charge. For me I just doubt I'd use the power advantage of the 40T in most of my riding conditions. Also the 50E is rated for 10A continuous meaning you could constantly drain 10A from it until it was empty without cell degradation. It also is rated at 15A per cell for intermittent use without damage. For those that want to do crazy climbs or try and get a speed record by all means the 40T is the way to go. I just don't think that is what the majority of the time most will use the wheel for and will be handicapped with a short mileage. 

Edited April 9, 2022 by BleepBloopBlop

[supercurio]

@BleepBloopBlop It's an interesting thought.

I'm not sure averages can be used to predict this accurately however, since riding can have a lot of peaks during accelerations, braking.
If you have access to log data, it could be interesting to slice into different buckets and see what draws the most power. Just an idea, I don't know what I'm talking about 

[Eucner]

1 hour ago, BleepBloopBlop said:

I've been monitoring my average power usage

I you should look for current consumption to know what kind of batteries work best for you.

[alcatraz]

5 hours ago, BleepBloopBlop said:

 

This picture basically explains the difference.

These cells are in their goldilocks zone (lab environment) of 20C ambient temperature, without vibrations, stable temperature monitored load. 

The line that goes up is one of the 50E cells reaching 75-80C temp and the test is interrupted. The voltage sag is quite big with 0.2v delta. Over the entire pack 0.2v amounts to 6.4v lower voltage on the 50E pack.

Good questions to ask oneself are: What about when...

...conditions aren't ideal?

...when some of the cells carry more of the current (imbalance)?

...when a heavy rider thinks he can fly up the climbs.

It's probably going to be ok for most people that aren't racing, and/or that don't live in hot environments, and/or in sub zero temperatures. 

Being a suspension wheel more people are going to be doing more (extreme) offroading and the packs are going to take a beating. It remains to be seen how they hold up and how the pack temps develop.

The same argument can be made for the S20 which has a similar configuration.

Heavy wheels without suspension like the Sherman have a massive safety margin over these new pack designs (in my opinion).

[BleepBloopBlop]

No one is going to pull 15A continuously on a unicycle. The over temp issue you mention is just not something that will occur in any EUC use case. 

You have to realize current and only current impacts the force a BLDC motor can generate. Once you hit coil saturation more current does not generate any additional motor force. 

Voltage and KV (winding) are what impact top speed if the motor can generate sufficient force to overcome drag losses. As the force required to maintain speed goes up, voltage sag occurs and top speed is reduced. This is why wheels such as the sherman do so well at top speed since they have little voltage sag with 3600wh battery packs.

For the majority of people I think they will require peak force not near top speed such as a high climb scenario. We will see what sort of force is required on this wheel to go 50+ to determine how voltage drop impacts top speed. I think the 40T is the best option outside of the significant reduction in range. 

Worth the read for those that want a more in-depth explanation. 
https://web.mit.edu/first/scooter/motormath.pdf

Edited April 10, 2022 by BleepBloopBlop

[alcatraz]

I'm talking about a combination of conditions. Any one condition can be refuted but what about when they all happen at the same time? 40C ambient temp climbing? -5C emergency braking after a fast charge in the cold? There are many combinations out there.

When you put low current cells in a relative low 4P configuration in the fastest wheel ever made, you ARE cutting the safety margin ever thinner and thinner.

The stress level per cell is going to be higher than other wheels. More stress equals a higher likelyhood of failure (somewhere down the line...)

I'm not saying don't buy. I want a Begode Master too. But I buy knowing it's a wheel design stretched thinner than many other wheels out there. If I get a 50E it's NOT going to be optimized for current critical situations, and if I do push it, I will be prematurely aging the packs requiring careful monitoring and maintenance (to ensure no fires etc).

Edited April 10, 2022 by alcatraz

[supercurio]

I'd give Marty a Samsung 50E config, and U-Stride a Samsung 40T one. As well as forbidding him to even try the 50E version 

[BleepBloopBlop]

Bahahaha. You all should tell the RS-HT owners how dangerous their wheels are with their current high capacity cells. This wheel is basically an RS-HT with more voltage for increased RPM/Speed.

[techyiam]

8 minutes ago, BleepBloopBlop said:

You all should tell the RS-HT owners how dangerous their wheels are with their current high capacity cells.

Jason has. Any owner of the 900Wh packs who had the fires would definitely now comprehend the warnings. There wiil still be many who will continue to be passive and hope all is well. Riders who abuse their batteries on a continuous basis, and not monitor their packs carefully will be exposed to great risk with time.

[Tawpie]

Can someone check my arithmetic because it doesn't quite make sense to me. This is a 32s4p configuration, that means 32 * 4 = 128 cells are providing the current to the motor.

I'm going to assume the MOSFETs, connectors, drive circuits, motor windings and all other aspects are fully up to the task for the following question.

How much current can I send through the wire between the controller and the motor? https://www.engineeringtoolbox.com/wire-gauges-d_419.html 

10 AWG stranded wires coming out of the controller seems to be traditional, this wire sizing would imply the designers expect to see up to 52 A flowing to the motor — 400 mA per cell. Maybe they're using 8 AWG solid wire, that's good for 586 mA/cell. Continuous operation, PVC insulated. More current in the wires than that and you have OG Shermans on overheat hill (didn't they 'fix' that by adding a fibreglas insulation oversleeve?). Either way, the per-cell demand is pretty low, well under 0.5C.

Yeah yeah yeah, these are continuous numbers. What about peak demand? Shaquille O'Neal doing his best MJ lean to zoom around that car when he's already at 45 mph and he hits a bump. Call that say, 10x the power demand—and remember we're already at the limit of what we should be sending through our motor wire for any length of time. That's still only 4 A per cell if the wires are 10 AWG, under 6 A for 8 AWG.

 

I don't know for certain, but based solely on how the motor wires are sized, and if my arithmetic is correct, you don't need high discharge rate batteries for their current, you'd only really take advantage of their lower internal resistance/lower sag… and that might actually truly save you if you punch it at 5% battery.

Edited April 10, 2022 by Tawpie

[Rolzi]

From information I received the current batch 50E (50E2/3) is performing much better than what those lygte-info tests show.

Edited April 10, 2022 by Rolzi