1640Wh - 67,2V / 1600Wh - 84V

[Hunka Hunka Burning Love]

What I don't understand is why they haven't hired @EUC Extreme as their lead improvement engineer.  That guy has got some crazy skills and obviously seems to know what he is doing. If anyone has stress tested these EUCs it's gotta be him.

 I mean who here has melted the friggin' solder off their motor connector leads on the control board by just riding their wheel?  If I was the head of Gotway I'd be keenly interested in @EUC Extreme's custom mods and maybe incorporate them from the start on my wheels.  Do you ever see him mentioning "Oh oh I've burned out a MOSFET?"

[zlymex]

46 minutes ago, Cloud said:

I still dont get Gotways logic is not only not increasing the charging speed but actually lowering the current.

the only possible logic I see is ok, we have 84v now, so to keep the connectors and wires exposed to the same , proven safe, power (IxV) and same temperature rise, lets lower the current............

well, if  you are worried that the connectors/ wires wont hold up, just replace them with more robust ones, how difficult can this be?

That's true. Obviously Gotway sticks to the fanless charger of the same casing. 84V/1.5A version already has more power than 67.2V/1.75A.

An 3A charger would be nice 

[zlymex]

12 minutes ago, HunkaHunkaBurningLove said:

 I mean who here has melted the friggin' solder off their motor connector leads on the control board by just riding their wheel?  If I was the head of Gotway I'd be keenly interested in @EUC Extreme's custom mods and maybe incorporate them from the start on my wheels.  Do you ever see him mentioning "Oh oh I've burned out a MOSFET?"

OMG, he hasn't.

[Hunka Hunka Burning Love]

We all started with baby steps!  He advanced to giant leaps (literally!).

 

[OliverH]

57 minutes ago, HunkaHunkaBurningLove said:

What I don't understand is why they haven't hired @EUC Extreme as their lead improvement engineer.  That guy has got some crazy skills and obviously seems to know what he is doing. If anyone has stress tested these EUCs it's gotta be him.

 I mean who here has melted the friggin' solder off their motor connector leads on the control board by just riding their wheel?  If I was the head of Gotway I'd be keenly interested in @EUC Extreme's custom mods and maybe incorporate them from the start on my wheels.  Do you ever see him mentioning "Oh oh I've burned out a MOSFET?"

No  But he definetly smoked a board (over voltage?). He's a pretty nice guy. He sees the "challenges" and fix then for his need and usage. 

[EUC Extreme]

In fact, I get burned every trip mosfets immediately if I do not watch out for it to do.
I have installed the fuse for it that I do not need to change the circuit board after each run. EUC is really tedious to carry home.
This is an unfortunate fact that none of the EUC can not stand my drive for 15 minutes longer.

I have never smoked EUC overvoltage, and I do not because of my own tunings.
Vice versa. None of the EUC would not survive my disposal if I do not make their own changes.

[EUC Extreme]

On 18.10.2016 at 3:42 AM, SuperSport said:

I recommend installing slime before riding.  It can sometimes prevent your tire from going fully flat.

I also carry this tool kit and pump.  It's quite small, fits well into a back pack.  There might be better options, but I got this one at a good price at the time.

https://www.amazon.com/gp/product/B00R0KHB3W/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I slime many different tires, so I buy it by the Gallon.  On these off road tires in the photo below, I had a 1/4 inch stick punch through the tire.  It held enough air to get me back to camp.  When I pulled the stick, it sealed up and I was able to pump it back up.  Never had another leak on that tire.

Never put the EUC ring liquid. It becomes impossible to control. Gyroscopic and moving the liquid is really a bad thing.

[EUC Extreme]

3 hours ago, zlymex said:

I got a news yesterday that that 84V/1600Wh version begin to sell in Chinese market(that originally targeted to oversea market only). The charger comes with the EUC is still 1.5A.

The friend of mine who bought the 84V slim version has just bought a 84V 10A charger, of which I've strongly opposed. He said the wires and the connector can be modified to suit 10A, and the 2.5A-per-cell charge current is Ok for occasional use although the temperature rise for batteries is high. Also, it is switchable between 5A/10A. However, he found out when the charger arrived it is too large and too heavy to carry.

Really, that size battery can safely load 16A.
Up to 32A charging, cells would be possible, according to specs.

 

[zlymex]

26 minutes ago, EUC Extreme said:

Really, that size battery can safely load 16A.
Up to 32A charging, cells would be possible, according to specs.

 

What you probably didn't know is that the battery of my friend's 84V version is a DIY, consisting of only 4 parallel cells, instead of 6 parallel.

It's pity I cannot see your videos on youtube, although I saw one or two in low resolution forwarded by someone else.

I did burn my board/MOSFET(67.2V 820Wh version) once when I failed to climb a 28 degree slope. 

[16bitSprite]

Either way has its positives and negatives. Fans will run the charger cooler and more effectively but with less moving parts, fanless is more reliable.

Quite frankly, I'll just be happy if the charger doesn't go up in smoke like my last one. Just lucky I noticed that burning electrical smell coming from the next room before it took my house with it.   

Lesson: 

NEVER leave your wheel charging unattended.

It is one thing to come home to a burnt down house. It is another if you are asleep inside when it goes up.

[Hunka Hunka Burning Love]

3 hours ago, EUC Extreme said:

In fact, I get burned every trip mosfets immediately if I do not watch out for it to do.
I have installed the fuse for it that I do not need to change the circuit board after each run. EUC is really tedious to carry home.

Could you give us mere mortals  some tips on what to watch out for to avoid MOSFET burnouts?  Is your fuse similar to what KingSong has incorporated in some of its wheels?  How often do you blow fuses and when does that tend to occur?  Do you have two stages of fuses so if one blows due to a spike in over-current that you have a backup that allows the wheel to continue functioning?  Or is that even possible?

I only have some rudimentary electronics knowledge so is there a way that when a fuse burns out that the circuit can trip to a secondary fuse so the device continues working? @esaj?

Would a PTC or bimetallic resettable fuse be fast enough to work?

http://www.littelfuse.com/products/resettable-ptcs.aspx

How about some sort of surge protection? 

[Chriull]

6 hours ago, zlymex said:

I got a news yesterday that that 84V/1600Wh version begin to sell in Chinese market(that originally targeted to oversea market only). The charger comes with the EUC is still 1.5A.

The friend of mine who bought the 84V slim version has just bought a 84V 10A charger, of which I've strongly opposed. He said the wires and the connector can be modified to suit 10A, and the 2.5A-per-cell charge current is Ok for occasional use although the temperature rise for batteries is high.

The temperatur rise for the batteries is really happening or that's "just" a theoretical argument?

2 hours ago, zlymex said:

What you probably didn't know is that the battery of my friend's 84V version is a DIY, consisting of only 4 parallel cells, instead of 6 parallel.

He has a 20s4p configuration? (20*4,2V=84V) Then one battery cell should have a capacity of 4880 mAh?!

I'd assume he used 3Ah or 3,5Ah cells and got a total capacity of ~1000-1176Wh?

Anyhow, according to http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries the recommended normal charging current should be 0.5-1C. So in his case 6-12A (7-13A)

... so nothing against a 10A charger, so far....

Just if one (or more) battery packs have some BMS protection activated, the others could get (way) too high charge currents!

Also depending on the battery pack configuration/BMS protection state the charge protection circuit could get quite stressed.

6 hours ago, zlymex said:

Also, it is switchable between 5A/10A. However, he found out when the charger arrived it is too large and too heavy to carry.
 

I personally have a 67,2V 8A charger (http://www.1radwerkstatt.de/epages/80603321.sf/de_DE/?ObjectPath=/Shops/80603321/Products/Ladegerät) - they are definetely big, but still absolutely not heavy! Dont't know if they can be adjusted to 84V - but if it's just the weight your friend should be able to find something similar on the asian web sites?

 

[zlymex]

13 minutes ago, Chriull said:

The temperatur rise for the batteries is really happening or that's "just" a theoretical argument?

He has a 20s4p configuration? (20*4,2V=84V) Then one battery cell should have a capacity of 4880 mAh?!

I'd assume he used 3Ah or 3,5Ah cells and got a total capacity of ~1000-1176Wh?

Anyhow, according to http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries the recommended normal charging current should be 0.5-1C. So in his case 6-12A (7-13A)

... so nothing against a 10A charger, so far....

Just if one (or more) battery packs have some BMS protection activated, the others could get (way) too high charge currents!

Also depending on the battery pack configuration/BMS protection state the charge protection circuit could get quite stressed.

I personally have a 67,2V 8A charger (http://www.1radwerkstatt.de/epages/80603321.sf/de_DE/?ObjectPath=/Shops/80603321/Products/Ladegerät) - they are definetely big, but still absolutely not heavy! Dont't know if they can be adjusted to 84V - but if it's just the weight your friend should be able to find something similar on the asian web sites?

 

The temperature rise for the batteries is based on practical charge case and theoretical calculation. 

Yes, he has a 20s4p configuration, of 80 cells, 1025Wh total, not 1600Wh. Each cell is NCR18650GA, 3.5Ah in capacity, standard charge current is 1.475A. This is the cell used in every Gotway 820Wh/1640Wh/1600Wh version so far:
http://www.datasheetspdf.com/PDF/NCR18650GA/974430/1

In general, the output voltage of a charger can be adjusted slightly, but not from 67.2V to 84V, because that will exceed the maximum design power. Even the output current can be reduced(and hence the power), it may exceed the withstand voltage of capacitors.

[esaj]

1 hour ago, HunkaHunkaBurningLove said:

Could you give us mere mortals  some tips on what to watch out for to avoid MOSFET burnouts?  Is your fuse similar to what KingSong has incorporated in some of its wheels?  How often do you blow fuses and when does that tend to occur?  Do you have two stages of fuses so if one blows due to a spike in over-current that you have a backup that allows the wheel to continue functioning?  Or is that even possible?

I only have some rudimentary electronics knowledge so is there a way that when a fuse burns out that the circuit can trip to a secondary fuse so the device continues working? @esaj?

With entirely "passive" fuses, I can't figure out off the top of my head how to "fall-back" to a secondary fuse when the first one goes. Paralleling them wouldn't work, the second fuse would probably blow at the same time as the first. Maybe some sort of active constant-current circuit could be used, but it could still lead to a face plant, if it wouldn't allow enough amperage for the required torque (but would save the mainboard). Not that much different from the overcurrent protection in BMSs, in the sense that you would still faceplant... The circuit would require a lot of cooling, as typically such (constant current limiting) circuits work in a way that when the current rises too high, they start to drop the voltage to limit the current, thus dissipating the "extra" power by themselves, which causes the limiting component (mosfet or such) to heat up.

 

1 hour ago, HunkaHunkaBurningLove said:

Would a PTC or bimetallic resettable fuse be fast enough to work?

http://www.littelfuse.com/products/resettable-ptcs.aspx

How about some sort of surge protection? 

The PTCs I've seen probably don't have high enough tripping current for heavy wheel use (I think 10-15A is the maximum I've seen), although they should be fast enough otherwise. Hobby16 once said that they've used PTCs in protection circuits where the device must be protected from stupid users connecting 12V or such devices to higher voltage or even directly to mains, and they're fast enough to cut the power and protect the circuits without any damage. So yeah, they should be about as fast as regular fuses, when it comes to cutting the power in most circumstances, although I think that at first they start to limit the current by dropping voltage before tripping completely(?)

Don't know much about surge protectors, but I think they're meant to protect from overvoltage (spikes), and not current...

[EUC Extreme]

On 24.10.2016 at 8:28 AM, zlymex said:

What you probably didn't know is that the battery of my friend's 84V version is a DIY, consisting of only 4 parallel cells, instead of 6 parallel.

It's pity I cannot see your videos on youtube, although I saw one or two in low resolution forwarded by someone else.

I did burn my board/MOSFET(67.2V 820Wh version) once when I failed to climb a 28 degree slope. 

Charge Amper amount does not affect the amount of battery cells. Only relevant capacities added.
Generally speaking, 18650 cells can be downloaded 1C current.
That is, if the cell size is 1000mAh, it can be downloaded 1A.
If there are two cells in parallel, the post can be increased to 2 Amps.

If one of the cell capacity is 2200mAh, 1C charge, it means 2,2a.
The two cells in parallel, the charge may increase 4.4 Amps.
Some cells can be downloaded at a rate of 2C, it means double the amps.

So therefore, 1600wh 16 000mAh can download 1C charge current of 16A.
If the loaded 2C, Amps can raise 32A.

The voltage does not affect this matter in any way.

1600wh charging the battery pack 2 amperes, is completely unnecessary. Charging a single cell strain so ridiculously low that it is excessive force.

Really, secure download is 16A.

[Yashaya Yasharahla]

Does anyone have a video link to a 22-inch 84V EUC? I'm dying to see one in action.

[Citi Wheel]

57.5 km/h top speed, gps confirmed according to Kevin Lee's post on facebook. If this is the speeds the 18" wheel can obtain, I can't imagine what the 22" wheel is going to be able to do

[Ben Wilson]

Lol. So, first off I have been riding alot and hadn't been on the forum for awhile. This is my first wheel and so I don't have anything to compare. However, when I charge the wheel, usually it is after dark and the next day I check it for green light. I guess it was 12 hours. I can go a week on full charge so it doesn't matter to me. It also breaks fine. At 40kph, I stop in about 15 feet or so safely. It handles well as I can now roll slow as people walking and still balance. I can also pass those high speed bike freaks who think they can't be beat. That's always fun to see their shock! Durable wheel too as I lay it down a few times a week on curbs or just goofing off. I did repaint with flex seal to protect it. Seems to work. 

 

 

[Shoe73]

@Ben Wilson Probably not a good idea to go to sleep while charging one of these things. If something goes wrong with the charging, you could wake up in a fire. These batteries contain so much energy, I would be really careful. 

[The Fat Unicyclist]

4 hours ago, Shoe73 said:

@Ben Wilson Probably not a good idea to go to sleep while charging one of these things. If something goes wrong with the charging, you could wake up in a fire. These batteries contain so much energy, I would be really careful. 

Would using a ChargeDoctor change the "risk?"

Or would something be just as likely to "go wrong?"

[Shoe73]

I would think the charge doctor would be helpful here to ensure you don't overcharge if you set it to stop based on voltage. There are also timers that plug into a power outlet, you could use one of those to ensure charging stops after a certain period of time. 

[SuperSport]

On 11/24/2016 at 9:17 PM, Ben Wilson said:

It also breaks fine. At 40kph, I stop in about 15 feet or so safely.

It really is a fantastic wheel, but you might re-measure this distance.  You don't want to be in a situation where you think you can stop in time, and you cannot.  15 feet is a VERY short distance at 24.8 mph.  You might plan a little more room than that, like maybe 2-4 times more room.

[nomad]

"Reaction times vary greatly with situation and from person to person between about 0.7 to 3 seconds (sec or s) or more. Some accident reconstruction specialists use 1.5 seconds. A controlled study in 2000 (IEA2000_ABS51.pdf) found average driver reaction brake time to be 2.3 seconds."

https://www.google.com/search?q=reaction+time+breaking

At 40 km/h you move 55 feet in 1.5 seconds, that's before you start braking and/or be able to do any evasive maneuver to begin with...

@EU GUY tested the braking distance on his ACM, at 35 km/h it was about 42.5 feet. It's not the 84V Msuper but for that wheel lets use 48 feet reaction time + 42.5 feet stopping distance. So total distance to fully stop for a 65 kg ACM rider at 35 km/h = 90 feet.

Stopping in 15 feet at 40 km/h  yeah right

 

[amadeusz]

On 12.10.2016 at 3:14 PM, Ben Wilson said:

Someone may know .. acm16 1600wh 84v when power cut speed how much battery% cut power

 

[swvision]

4 hours ago, amadeusz said:

Someone may know .. acm16 1600wh 84v when power cut speed how much battery% cut pow

Best thing to do with the 84v or any other euc is to use the egg app and keep an eye out for either the voltage drop or the battery percentage while accelerating on your wheel, that's what I do. When you are at 20% battery and you see that when you go over 15mph the battery drops to 10%, for example. That just means you have to reduce speed. It's very important to keep track of this or there will be a cut out and youll go flying off your wheel.