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Generic OEM - Unicycle-A2

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Hi People,

I tried an electrical unicycle about one and a half month ago at a barbecue, after that, I immediately ordered one :)

 

Update

  • I measured the range using a gps on a real track, and apparently it has the better range than first noted ~10km, I have updated the text accordingly.
  • After increasing the tire pressure from ~1bar to 3.1bar, the range was increased by 3 km to ~13km

 

I purchased the cheapest electrical unicycle  I could find on amazon.co.uk - no specs, and I expected to pay import tax, luckily, that didn't happen.

Now, since I'm  starting to get annoyed about various aspect, I trawled the net until I found the manufacturer... it is here:

http://www.mywheel2014.com/product/product-47-79.html

 

Some stats:

Price:  297€

Motor-Power: 350W (Probably a bit smallish for me, my weight is ~78kg)

Specified range: 18-20km

Real Range: approximately 13km, (I will have to find some flat track with known length to test more exact.)

 

Pros:

  • Cheap
  • Fun to ride while full battery (20min)

Cons:

  • Weak battery (Only really fun for 20min, ok perhaps 30 min)
  • Horrible build quality (The battery lid broke off in a crash and the battery fell out...)
  • hurts the calves
  • Gets unstable to ride after 25min, so you have to be very careful with acceleration.

I can supply some more pictures documenting how it is possible to make the worst imaginable design for the hull... Hint, the battery lid, the thing that the rubber part folds around. There is nothing but the screws to help the lid withstand frontal force.

 

Here are some pictures of the beast:

20150709_002.thumb.jpg.ba2f83cb17b5ed47d

20150709_003.thumb.jpg.dae8474928d5cf44b

And the part that have fallen off (Fixed with Gaffa-tape)

20150709_005.thumb.jpg.f7a60df81bc958a1b

 

Edited by cg
Increased tire pressure => increased range

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I took it on a ride yesterday in a park near Copenhagen where I live,

After around 10km, it politely asked me to step down by raising the pedals, beeping and blinking :)

The path was fairly flat, and consisted 50% of pavement, and 50% of gravel / stones, the machine was behaving nicely for around 25min (6km), after that, when passing a small raised bridge, the bike had its first minor minor shake. (Torque lost long enough to feel it, but no crash since I was starting to expect it... )

Now I know the bike enough that it would have the shakes whenever I do normal acceleration... So I have to ride it really really smooth for keeping the bike behaving :)

Alas, It was a good ride, and I was riding a place where I had not been before.

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You could possibly increase the range a little by upping your tyre pressure.

It has a surprisingly big effect on both available power and range because you are reducing the rolling resistance. It will also make the wheel more manoeuvrable but the downside is that it will be less comfortable on rough surfaces and a bit more twitchy and less stable at speed.

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Hi Gimlet.

Thanks for the advice. I had very low pressure, just about one bar (I was sure I had about 2 bars... :/), After increasing the pressure to 3.1bar all you said was felt pretty much immediately.

I was surprised by the increased top speed, I was going 18km/h on average for the first 15min. The range for the trip was around 13km, 3 km more than I have managed with the low pressure.

Measured range

  • Trip 1: Tire Pressure ~1bar, range ~10km; beeping speed ~12km/h; Conditions: 50/50 on asphalt/gravel, small and short hills
  • Trip 2: Tire Pressure ~1bar, range ~10km; beeping speed ~12km/h; Conditions: 50/50 on asphalt/gravel, small and short hills
  • Trip 3: Tire Pressure 3.1bar, range ~13km; beeping speed ~18km/h; Conditions: 90/10 on asphalt/gravel, long hills

The beeping speed is while the battery is full, the speed drops while the battery level drops. The last ~2km is painfully slow.

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Apparently i should not push it...

Two days ago, Tuesday, I was driving a forest trail, nothing to bad, but with more hills than usual... Battery  down at one dot, remaining path was mostly downhill, so I cruised slowly towards where my car was parked...

at the end of a small hill I had a shutdown... I have never had a shutdown before, normally it would throw me off and start beeping on the ground, butthis time it was not able to turn on afterwards...

Today I wen't out riding again,

  • After a few meters, uphill, the unicycle had a shutdown, and it would not turn on again. (the battery indicator was 4 dots ~=  100%)
  • After driving home, I tried to turn on the cycle again, it turned on with 4 dots, I drove perhaps 200m, and went up a transition from road cycle path, and it turned off.

After getting home I attached the charger, and the bike was fully charged after around 10min, any idea what could be wrong?

Update

When shaking the wheel, I could hear something rattling inside, so I opened the compartment where the controller is, the controller board sits in the compartment with no protection whatsoever...

20150716_001.thumb.jpg.1bb182dcd88afa327

and here are some stones besides the controller...

20150716_003.thumb.jpg.33c403c1617b2124b

And this is what was on the table after shaking the unicycle...

20150716_006.thumb.jpg.de2105bddeca5242c

oh well, I don't know if this is really the cullprit.. are stones conducting?

Edited by cg
Adding pictures of unprotected controller board with stones

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The symptom you describe ("won't restart until it's plugged in") sounds like a Battery Management System shutdown. The way it's happening may indicate a problem with the battery. Search for "BMS shutdown" here on the forum and start with this thread: http://forum.electricunicycle.org/topic/478-brands-with-without-unexpected-shutdowns-new-buyers-look-here/

Unfortunately many if not most wheels are like yours, where the battery and control board are pretty exposed to the wheel through various holes like the ones at the top of that compartment. You might open the other side to see if there are any similar issues with the battery. Some cheap fix like tape over the holes may be enough to keep the junk out. I glued a piece of stiff plastic to the top inside of my wheel as a mud flap, there's a picture of it in this album: http://imgur.com/a/rEv6a

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The symptom you describe ("won't restart until it's plugged in") sounds like a Battery Management System shutdown. The way it's happening may indicate a problem with the battery. Search for "BMS shutdown" here on the forum and start with this thread: http://forum.electricunicycle.org/topic/478-brands-with-without-unexpected-shutdowns-new-buyers-look-here/

Unfortunately many if not most wheels are like yours, where the battery and control board are pretty exposed to the wheel through various holes like the ones at the top of that compartment. You might open the other side to see if there are any similar issues with the battery. Some cheap fix like tape over the holes may be enough to keep the junk out. I glued a piece of stiff plastic to the top inside of my wheel as a mud flap, there's a picture of it in this album: http://imgur.com/a/rEv6a

I am afraid you are right, now, after charging it, I did some wobbling back and forth, nothing crazy, and it in a matter of seconds turned of and could not turn on again:(

I have now taken out the battery, interestingly, the web-address on the battery seems to be a dead end. ( http://www.sztnt.com.cn ), at least it is dead for me.

I will unwrap now and post images of  the circuit

It is a 16cell battery, there is some paper well glued on both sides, especially the side away from the circuit board

This is the part of the circuit board i guess is interesting for shunting?

20150716_008.thumb.jpg.00d56e6c4e853adfc

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I am uploading the full picture instead,

20150716_011.thumb.jpg.4e24c17e3d1cc4453

@hobby16 do you have any advice on how to shunt this, and if it is the right thing to do based on the problem I have?

Edited by cg
adding image :)

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I am uploading the full picture instead,

20150716_011.thumb.jpg.4e24c17e3d1cc4453

@hobby16 do you have any advice on how to shunt this, and if it is the right thing to do based on the problem I have?

Here's the thread:

This should be the general idea:

The idea is to connect the battery's 0V (B-) directly to the power output (P-), bypassing the mosfets T1 responsible for the stupid cutoff : see the dotted green line in the schematics below. (B-) and (P-) are now standard markings on most BMS boards, so any BMS can be modified by laymen based on this  principle.

I see the P-minus -point at the top of your image (black wires), and I *guess* the B-minus is next to B+ (the minus might be obscured in your image) at the lower part of your image. But I'm not 100% sure on this, so better wait until you get confirmation... ;)

Edited by esaj

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Here's the thread:

This should be the general idea:

I see the P-minus -point at the top of your image (black wires), and I *guess* the B-minus is next to B+ (the minus might be obscured in your image) at the lower part of your image. But I'm not 100% sure on this, so better wait until you get confirmation... ;)

Yes, I am thinking the same, but I am uncertain of the role of the white stuff around the hidden B?, Also, the light green part between the B+ and B?, isn't that conductive?

I must admit I am a bit nervous about mangling with this battery, I better make sure no one is below the window so I can throw it if it starts to burn :/

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Can you measure the voltage on each of the cells? I'm wondering if one or more is defective. What brand are they? When you bought the wheel did it advertise a specific battery type? Sometimes they'll say "Samsung battery".

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Can you measure the voltage on each of the cells? I'm wondering if one or more is defective. What brand are they? When you bought the wheel did it advertise a specific battery type? Sometimes they'll say "Samsung battery".

Honestly, I was to eager ordering, so I didn't look at the specs, just the price... now I am a bit wiser... Anyway, I purchased it from amazon.co.uk, via lightinthebox... I will try to file a claim that the battery is defect and see what happens... it didn't say anything about samsung batteries as far as I remember, if I visit the old order now, I can see they claim it is 176Wh

I cannot really get access to the cells only the circuit board, so I am not sure where to measure.

20150716_011.jpg

Edited by cg

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Often the saying 'you get what you pay for' isn't necessarily true, but with an eWheel it certainly is. There is no substitute for quality batteries, a decent control-board, shell & motor. 

I don't quite understand the psychology of people who are looking for the absolute cheapest eWheel. Do they also buy ladders made out paper, tires without tread, or insist upon sky-diving with the cheapest parachute? When you reflect that unlike a bicycle, car or any other traditional form of transport there is no passive redundancy if [when] things go wrong. Why is it they're prepared to take these risks with low quality eWheels? 

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Often the saying 'you get what you pay for' isn't necessarily true, but with an eWheel it certainly is. There is no substitute for quality batteries, a decent control-board, shell & motor. 

I don't quite understand the psychology of people who are looking for the absolute cheapest eWheel. Do they also buy ladders made out paper, tires without tread, or insist upon sky-diving with the cheapest parachute? When you reflect that unlike a bicycle, car or any other traditional form of transport there is no passive redundancy if [when] things go wrong. Why is it they're prepared to take these risks with low quality eWheels? 

Hi Jason, you don't need to refer to 'the people' you can address me :)

In Denmark, and in EU in general, we have a 2year warranty, so that has probably helped softening my mind, usually, my primary rule for purchasing is that I can drive to the shop, and that the address is clearly visible on the web-site... In this case I ignored this rule...

anyway, it's quite easy.

  • I /was/ thinking the controller would be the same in all unicycles.
  • I did not think much about the battery.... more like; how bad can they be?
  • I had just tried another 'cheapest' which for me was like magic.

So, I wish I had done some research before, but in my case it was really lack of knowledge and over eagerness...

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To be fair to Jason, cg, I think he really was speaking generally about a huge number of people all over the world.
In harder times, everyone still wants what they want but they have to look more carefully at their financial outlay.
Even going into a supermarket, we all still fall for the cheaper pizza which has little topping and cheese that isn't cheese!!

On Jason's website, he does actually mention about customers often ending up buying from his website after they originally bought an 'inferior' version elsewhere.
So you're definitely not alone!
 

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My justifications for getting a cheaper generic first were that

  1. I knew my (since cancelled) Ninebot-order would take nearly a month, as they told me the shipment was a "little late" when I ordered, and I was impatient :D
  2. I didn't want to scratch the "better" wheel during practicing
  3. If it would have turned out that I don't like/can't ride an EUC, I could have cancelled the Ninebot-order and lose less money

In the end, it turned out that I learned it fairly fast and just loved it (and still do). I did cancel the Ninebot-order in the end (after waiting for something like 40+ days), as I had already bought the Firewheel from vee73, and didn't feel like I need another 16" wheel with similar range and lower speed. Still, I don't consider the money "wasted" on the generic either, learning on it was fun and it's better for letting other people (first timers) try riding... I think the Firewheel isn't the best choice for first wheel, due to lacking safety, high top speed and very responsive sport-mode (the comfortable-mode on the other hand might be too soft for practicing too, I've found it pretty useless due to being too soft).

Edited by esaj

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To be fair to Jason, cg, I think he really was speaking generally about a huge number of people all over the world.
In harder times, everyone still wants what they want but they have to look more carefully at their financial outlay.
Even going into a supermarket, we all still fall for the cheaper pizza which has little topping and cheese that isn't cheese!!

On Jason's website, he does actually mention about customers often ending up buying from his website after they originally bought an 'inferior' version elsewhere.
So you're definitely not alone!
 

Yeah, I know, I am not angry at @Jason McNeil at all. But, it is definitively more easy to answer the question for a specific persons than for a blurry population, and it is not unlikely that I will end up being from Jasons website, for now I will see if I can get the wheel up and running and use it for some more.

My justifications for getting a cheaper generic first were that

  1. I knew my (since cancelled) Ninebot-order would take nearly a month, as they told me the shipment was a "little late" when I ordered, and I was impatient :D
  2. I didn't want to scratch the "better" wheel during practicing
  3. If it would have turned out that I don't like/can't ride an EUC, I could have cancelled the Ninebot-order and lose less money

Different reason with more thoughts about it than me :),  we should make a thread: "Why do people by cheap wheels"

 

Anyway, I found a multimeter, And I have done some measurement on the battery, I will update here in about half an hour.

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Sorry, I was in one of those rant moods :angry: Especially on the FB forum, there are quite a few cases of people buying the absolute dirt, then asking for assistance when it breaks down. For safety there really ought to be a minimum set of standards like:

  1. Certified quality manufacturing of the batteries
  2. A BMS which will not cut-out under moderate load
  3. If <20 cells, then the eWheel must have pedal-tilt-back to prevent riders from over-powering them
  4. If it claims to supports speeds above 18kph, then all the elements of the eWheel must support it (battery, control-board, motor)
  5. Manufacturers must not advertise speeds at which they cannot safely attain

I hope you're able to easily identify & solve the faulty eWheel :)

 

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Sorry, I was in one of those rant moods :angry: Especially on the FB forum, there are quite a few cases of people buying the absolute dirt, then asking for assistance when it breaks down. For safety there really ought to be a minimum set of standards like:

Definitively no problem.

 

I have done some measurement on the battery now, and it seems like the is something horrible wrong with the cells, measuring the voltage over b2+ to b3+ only gives 0.450V

20150716_011-annotated.thumb.jpg.97af932

I guess this mean that shunting the battery is not the right right sollution,

I have now opened into the actually cells, these two are the bad cell, it feels like the might be glues into 6 cell structure, do you think there are any hope in replacing just the two cells?

20150717_001.thumb.jpg.cea92f53e25701e2a

Edited by cg
Added image of faulty cell/cells

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Sounds like a dead cell to me, although I have no experience with such things... but the other voltages sound like maximum voltages for the cells (fully charged). AFAIK, the single faulty cell can be replaced, but should only be done with a similar spec'd cell, and probably not something that laymen should try, at least without consulting someone who knows how it should be done (not me ;)) and what should be taken into account. Maybe @hobby16 or @vee73 can give more pointers? You could also ask around if there's some company or someone who knows their way around battery assembly, a single cell isn't that expensive and a professional can probably replace it pretty easily. Are there any markings on the cells to identify the manufacturer and model?

Edit: just saw your edit, looks like the cells are these:  http://item.taobao.com/item.htm?id=37504849790

The problem is that this is some chinese cell, which may or may not be harder to come by in the western countries... I don't know if it could be replaced with some other cell which has the same specs (capacity, chemistry, charge voltage, charge/discharge current etc).

 

 

 

Edited by esaj

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...Are there any markings on the cells to identify the manufacturer and model?

Yes, as you almost can se on the picture, which I might have added after your comment, is LR1865SI

the first hit is this, http://m.en.lishen.com.cn/products_detail/&productId=22&pmcId=15.html which doesn't seem completely off.

Edit: just saw your edit, looks like the cells are these:  http://item.taobao.com/item.htm?id=37504849790

The problem is that this is some chinese cell, which may or may not be harder to come by in the western countries... I don't know if it could be replaced with some other cell which has the same specs (capacity, chemistry, charge voltage, charge/discharge current etc).

well ¥18.00 is so cheap that there is no harm ordering them, except if those taobao are to shady :), it surely look like the right cell.

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I recommend to measure directly to the cells voltage. Then you will know whether they are ok.

 

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