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Accident Report 9b1 e+


fluidfred

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I had an accidient by a power cut off.

Drove  at max speed when the 9b1 E+ as pulled the pedal back, I moved back and when leaning forward again then  suddenly lost power.

Result: Lots of  excoriations of the reight half side of my body. Mainly landed on the right hip causing a serious

laceration which had to be stiched in hospital. Later clottted blut had to be taken out by an operation. 4 days in hospital.

Really dont trust the device any more.

Just recently my nabour  had a similar expierence with another 9b1 e+ from a friend, however lower speed and injury not as serious.

Date of purchase: May 21, 2017
Model Ninebot One E+
Firmware version, can be provide when I am out the hospital
Milage total 150km
Speed approx. 22km
Use of app (yes or no) no
weather conditions, good and sunny
road conditions, try tar road
battery charge  90%
wear and tear, 

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59 minutes ago, fluidfred said:

battery charge  90%

This sounds like a mirror copy of my only real faceplant on my KS-14. I accelerated smoothly up to max speed on the flat showing off and then leaned back to brake (but not aggressively) All of a sudden the wheel went 'floppy' but, surprisingly tipped me off forwards. It was all so sudden it is hard to remember it exactly, but possibly it failed as I leaned forward to release the brake as I was only aiming to slow down enough to do a 180 degree turn on a wide path. Just scrapes, bruises and painfully sprained wrist that took months to improve.

My conclusion was that it was the result of trying to brake with a nearly full battery, it was the start of a very long ride, ( that I still completed ) so I'd put every watthour of energy I could in the battery but I had already ridden 1/2 mile or so.

It was months before I could bring my self to ride faster than the first beeps, and I now use a charge doctor to limit the battery charge unless going on a very long ride where I am really careful for the first couple of miles. Never had another fall in 20 months riding other than stupidly catching a peddle on a bollard which was entirely my fault - it was, of course, the one time I wasn't wearing wrist guards and the same wrist took even longer to heal.

Bottom line: none of the EUC's (with the possible exception of Inmotion as I've not heard of an incident with them) seem to be able to  handle braking with a close to full battery well.

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3 hours ago, fluidfred said:

I had an accidient by a power cut off.

Drove  at max speed when the 9b1 E+ as pulled the pedal back, I moved back and when leaning forward again then  suddenly lost power.

Result: Lots of  excoriations of the reight half side of my body. Mainly landed on the right hip causing a serious

laceration which had to be stiched in hospital. Later clottted blut had to be taken out by an operation. 4 days in hospital.

Really dont trust the device any more.

Just recently my nabour  had a similar expierence with another 9b1 e+ from a friend, however lower speed and injury not as serious.

Date of purchase: May 21, 2017
Model Ninebot One E+
Firmware version, can be provide when I am out the hospital
Milage total 150km
Speed approx. 22km
Use of app (yes or no) no
weather conditions, good and sunny
road conditions, try tar road
battery charge  90%
wear and tear, 

Four days in the hospital?  Wow, what a terrible result.  Sorry to hear you got hurt so bad.

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That is terrible, and I'm sorry to hear about your injuries.

I think it cannot be said enough, NEVER, EVER, ride at top speed if you don't want to be hurt.  There is only so much this technology can currently do to help when you are at the top speed of the wheel.

That's not saying you cannot ride at top speed, but if you do, then be prepared with riding gear, helmet, etc, and expect to fall off at some point. It WILL happen eventually.

Again, sorry about your injuries, and your fear of your wheel.

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4 hours ago, fluidfred said:

I had an accidient by a power cut off.

Drove  at max speed when the 9b1 E+ as pulled the pedal back, I moved back and when leaning forward again then  suddenly lost power.

Result: Lots of  excoriations of the reight half side of my body. Mainly landed on the right hip causing a serious

laceration which had to be stiched in hospital. Later clottted blut had to be taken out by an operation. 4 days in hospital.

Really dont trust the device any more.

Just recently my nabour  had a similar expierence with another 9b1 e+ from a friend, however lower speed and injury not as serious.

Date of purchase: May 21, 2017
Model Ninebot One E+
Firmware version, can be provide when I am out the hospital
Milage total 150km
Speed approx. 22km
Use of app (yes or no) no
weather conditions, good and sunny
road conditions, try tar road
battery charge  90%
wear and tear, 

Thank you for sharing your story - I am very sorry to hear about your accident and injuries, and wish you a speedy recovery.

 Personally, I think trust is something we have to earn in our own understanding through the time we devote to bonding with the machine. One month of ownership is not enough to be competent at riding at the speed limit, nor to be fully aware of the idiosyncracies of any EUC.

That said, you could become a much wiser and more skilled rider from this experience and, given time, feel confident about riding again. 

 

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1 hour ago, MaxLinux said:

I am surprised by this recent purchase date because I thought Ninebot stopped making the One E+.

According to electricunicycleonline's website, they stopped production and are out of stock, they recommend IPS.  There must still be some available on Ebay and other places.  Speedyfeet still shows them in stock.  

Ninebot ONE E+ (Gen2) Electric Unicycle

Regular price£579.17 | £695.00 including VAT

 

Want it Tuesday, 4th July?
Order within
1Day16Hrs29Mins
Select Fedex 24 (UK Mainland)
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That's very strange to hear about a new wheel cutting out like that. How much do you weigh?  Were you alarmed by the tiltback and tried to brake really hard?  I usually charge to 100% and zoom up to near or at tiltback speed where I back off a little to resume normal pedal orientation.  I don't try to brake really hard unless I have to as that can stress the wheel's electronics.

What protective gear were you wearing?  Were you riding aggressively?  Quick leans?  Was it an older wheel bought second hand in May?

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I don't know if NineBot can pair with WheelLog but I strongly suggest doing so then riding while observing the wattage usage. You might be surprised at where the wattage usage approaches dangerously high levels.

For me:

--Going downhill uses the most energy.

--Braking while going downhill is really quite dangerous.

--U-shaped cement sidewalks, where you go up and down, up and down, have huge spikes of wattage. I would never have guessed.

--The initial acceleration from a dead stop can be large and highly variable depending on just a little bit of difference in leaning.

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34 minutes ago, LanghamP said:

--Going downhill uses the most energy.

 

10 hours ago, Keith said:

My conclusion was that it was the result of trying to brake with a nearly full battery, it was the start of a very long ride, ( that I still completed ) so I'd put every watthour of energy I could in the battery but I had already ridden 1/2 mile or so.

  This confuses me. I've seen multiple posts where riders have used WheelLog and seen huge power consumption on downhill braking and then other posts where regerative braking on downhill is discussed. Which is it... Or is it both?

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It's both.  Braking is accomplished when regenerative braking is applied.  It causes a LOT of energy to pass across the board, not out, but in.  Can still cause cutouts if the power is too great, or if your battery is too full.

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11 hours ago, fluidfred said:

I had an accidient by a power cut off.

 Very sorry to hear of this accident. Glad you are on the mend. I think I will run Wheellog or Darknessbot at all times on my wheel so if it fails I'll have some closure as to why.

4 hours ago, MaxLinux said:

I am surprised by this recent purchase date because I thought Ninebot stopped making the One E+.

There is a brand new sealed C+ on eBay right now so I guess new units are around. That one is from Fl. If it has been stored in a Fl garage for the last year I imagine the battery would be badly worn through the temperature. Maybe something similar for fluidfred.

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6 minutes ago, SuperSport said:

It's both.  Braking is accomplished when regenerative braking is applied.  It causes a LOT of energy to pass across the board, not out, but in.  Can still cause cutouts if the power is too great, or if your battery is too full.

 So Wheellog is not differentiating between current direction? I also thought regerative braking didn't return much to the battery. These reported values sound substantial. Clearly I need to read up on it.

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I believe there is one app that shows when it's going in instead of out, but I don't remember which one.

There is a great amount of power going in during braking, but the battery can only take so much of it safely at one time, so the extra is bled off as braking and heat.

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I thought I read somewhere that certain wheels don't indicate the direction of the current (KingSong or Gotway) so it's difficult to tell whether energy is being consumed or stored.

I would doubt that it takes more energy going downhill than uphill.  You might just not be realizing from the graph that the power is being diverted back to the battery.  There is a whole thread about regenerative braking somewhere...

Here's a power graph of my typical run using Gyrometrics:

779735_img2711.png

And the corresponding battery charge graph:

304529_img2712.png

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15 minutes ago, SuperSport said:

Here is an example of my MSuper when going down and then back up my driveway.  You can see it creates more going down.  And yes, my driveway is VERY steep.

2hdz40n.jpg

Isn't this close to, or exceeding, the wattage of the MSuper? Is not the downhill close to a cutout or something bad?

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Yes, I believe it's close to cutting out. I would not want to push this much for very long. This is a short piece of my driveway, maybe 30 feet or so. 

Correct @Hunka Hunka Burning Love, mine is showing in and out, but the app does not show which direction. There is one that shows the direction, but I don't remember which it is. 

Having ridden for a long time, and understanding how these work, I usually know whether it's pushing or pulling. 

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3 hours ago, SuperSport said:

Here is an example of my MSuper when going down and then back up my driveway.  You can see it creates more going down.  And yes, my driveway is VERY steep.

2hdz40n.jpg

 Wow. That is a huge amount of power in. Quote scary actually. After seeing this I'll be treating breaking and downhill runs with some serious respect.

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3 hours ago, LanghamP said:

Isn't this close to, or exceeding, the wattage of the MSuper? Is not the downhill close to a cutout or something bad?

 So I'm getting a V8. Total battery power 1440Watts I think. If I experienced this level of charge from regenerative breaking I'd have cut out? I'm guessing that even of the battery isn't full the charging circuit will shut off if excess current goes in. Over 1C for example.

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16 minutes ago, WARPed1701D said:

 So I'm getting a V8. Total battery power 1440Watts I think. If I experienced this level of charge from regenerative breaking I'd have cut out? I'm guessing that even of the battery isn't full the charging circuit will shut off if excess current goes in. Over 1C for example.

Not on the discharge-side (through which the braking current enters), it shouldn't. I've had the kind of BMSs that have same points for both discharging & charging, and it really sucks to have the overvoltage charging-protection on the discharge-side cutting power in downhill during braking... Then again I've probably overcharged the original Firewheel packs multiple times going downhill the first thing in my trips, with fully charged (<50mA charging current left) wheel "hot" off the charger, and never had a cutout. In a "proper" BMS for this use you have separate protections for the charging & discharging side, and the discharging-side overcurrent protection is easily 10 times the C-rating of the cells (30...60A, whereas 1C charging for most cells is 2.2...3.5A) and there's no overvoltage protection (it should be up to the firmware to warn of overvoltage at that point, not BMS cutting the power). You will easily exceed the 1C rating in braking just going downhill, the momentary spikes can be really high even for low-weight riders. The cells cannot soak it all, so a lot of it is burned off as heat in different parts of the path, and it should be mentioned that there have been cases of Ninebots (and other wheels) burning the mosfets during powerful braking. Still, if you have to do an emergency power-braking, then you have to do it, no time second-guessing if the board can take it. Also power braking is still an essential skill for safe riding, so you shouldn't put off learning it in fear of burning the board.

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5 hours ago, LanghamP said:

For me:

--Going downhill uses the most energy.

@SuperSport, my reply was actually in response to LanghamP's statement.  I should have quoted it earlier.  When I said "you might not realize from the graph" I was referring to LP, not you, seeing your graph and realizing the power readings are absolute values.   :innocent1:  

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