InMotion V8 tried to kill me Suddenly

[who_the]

The V8 is an awesome wheel. But it can be overleaned. I have done it twice myself (both with no warning), and have witnessed it as well. I've known it to happen during initial acceleration and also at cruising speed. An overlean is not an indictment of one's riding ability, or a sign that your wheel can't be trusted. It's merely your forward momentum asking for a bit more power than your wheel can offer.

[Barry Chen]

On 2017/3/6 at 11:26 PM, charlesrg said:

Today I was riding my V8 on my daily commute like I've been doing it for 2 months. I was around 15mph on asphalt flat terrain, when suddenly the inmotion v8 gave up and I went body against pavement. It didn't play any different warning sound it just suddenly didn't do anything.

As I've had a couple events where the wheel slowly titled completely and now gave up totally, is there a data logger where I can retrieve the wheel facts of the issue ?? I really want to know if something failed, overheat, frozen, over-speed. I can't really trust it, this thing might be trying to kill me. Maybe it has a buggy firmware, this device must have a log memory that logs every event and then later be retrieved, just like a tesla car.

Facts:

• As I dragged myself to grab it out of the road I noticed the blue lights were still on.
• Temperature this morning 30 degrees Fahrenheit.  About -2 celsius.
• Battery was probably around 92%. I do full charge at home and I had only ridden about 1.5 miles.
• I've set its max speed to be 19mph so the wheel beeps at 16mph and start tilting back. Not sure if it's even possible to go to 19mph as it plays the warning sound and tilts back.
• Yes, lots of cuts, lacerations and pain. Lucky is winter and I was riding with a big jacket. Not sure if I had any major complication as I'm still waiting for the pain to go away.

On 2017/3/6 at 11:26 PM, charlesrg said:

Today I was riding my V8 on my daily commute like I've been doing it for 2 months. I was around 15mph on asphalt flat terrain, when suddenly the inmotion v8 gave up and I went body against pavement. It didn't play any different warning sound it just suddenly didn't do anything.

As I've had a couple events where the wheel slowly titled completely and now gave up totally, is there a data logger where I can retrieve the wheel facts of the issue ?? I really want to know if something failed, overheat, frozen, over-speed. I can't really trust it, this thing might be trying to kill me. Maybe it has a buggy firmware, this device must have a log memory that logs every event and then later be retrieved, just like a tesla car.

Facts:

• As I dragged myself to grab it out of the road I noticed the blue lights were still on.
• Temperature this morning 30 degrees Fahrenheit.  About -2 celsius.
• Battery was probably around 92%. I do full charge at home and I had only ridden about 1.5 miles.
• I've set its max speed to be 19mph so the wheel beeps at 16mph and start tilting back. Not sure if it's even possible to go to 19mph as it plays the warning sound and tilts back.
• Yes, lots of cuts, lacerations and pain. Lucky is winter and I was riding with a big jacket. Not sure if I had any major complication as I'm still waiting for the pain to go away.

 

Please let me know how do you guys troubleshoot falls, if I can retrieve logs it will be very useful.

Please let me know how do you guys troubleshoot falls, if I can retrieve logs it will be very useful.

Hope you will be better soon.Especially in winter ,the battery works poor efficiency.As you say all about this is normal,but suddenly blackout.I think u should take it to check out and make protection next time to ride.

 

[US69]

@DavidM

NoBody wants to blame you for something....

You have to understand that here in the Forum, most of the Users have a lot of knowledge of EUC's...so for most of the members it is pretty clear that an overlean and/or cut-off can happen.

Unfortunatly that wasn't clear for you and now you experienced it the hard way.

Especially on Batterie under 50% there are some reports now of the V8 shutting off, especially when the wheel allready has some/a lot miles down the road.

Ipersonnally would think that after they have done a lot of mile the battery seams to get a bit weaker. The V8 only has 2 parallel battery Systems, that means that heavy acceleration stresses the Batterie much more as on a 1600wh wheel....and what CAN follow is that the battery gets more voltdrops and so on acceleration with low battery can cut-out.

 

In fact: Yes, that can happen to ALL wheels! So we are Kind of suicidal ;-)

You have to accept that driving on an EUC is or CAN be a dangerous Thing: Just one Little Piece has to fail, that might be a small conducter/resistor/mosfet on the Motherboard, or one of the 40cells got bad...or a wire burnes..... and The EUC willl cut-off and send you flying! That is NOT the norm...but it CAN happen....as there is NO redundancy whatsoever!

If you dont want that risk....yes, you have to drive a scooter....or a e-bike....as These have 2 wheels in case of failure you just roll on....

 

Other than that:Welcome to the Forum!

 

 

[WARPed1701D]

In the interests of science (and because I forgot my work pass today so got an extra ride home and back this morning) I managed to test my V8 at 30% bettery to determine the tiltback speed.

47% 29.89kph
41% 29.19kph
38% 28.56kph
30% 28.01kph
29% 27.87kph
28% 27.85kph

Several of these tilback alerts came as I was accelerating out of a curve and some of those were immediatley preceeded by a high current draw alert. In particular when I came out a curve at 30% battery the first alert I received was "High load at speed 27.41 and current 24.99" followed by "Tiltback at speed 28.14 at limit 28.01". 24.99 Amps! And honestly I wasn't really even leaning hard into the wheel! Think about that for a second. The V8 is equipped with LG MH1 batteries (rated at 10A max discharge current) in a 2 parallel configuration (2 x 10A = 20A max discharge current for the pack). At a 24.99A draw I was pulling 25% more power from each cell bank than the manufacturer rated and I wasn't even trying. This is on a fairly new wheel (2 months) with 250km on it and just a handful of charges on the cells. This is probably why I got through this without a fall.

Knowing this I feel that if you accelerated hard at 25kph and with only 30% battery on a wheel with 1000 miles on it (multiple charges and some aging of the cells) you quite simply overwhelmed the ability of the battery pack to supply the required amount of power to the motor. The wheel could not provide the torque to catch up your lean and you faceplanted.

The V8 is a great wheel but it has limitations. It is a mid range wheel and you are asking high end performance from it. If you want to be doing >25kph and still lean hard you need to look at a KS16S or better still a 18S or one of the Gotway models.Oh and pad up to the hilt.

Edited September 18, 2017 by WARPed1701D

[WARPed1701D]

Oh and 1 more bit of info. At 25 - 28 kph  crusing on flat ground current draw is nominally between 7 and 10 amps. So you can see that acceleration puts a massive extra demand on the battery.

Edited September 18, 2017 by WARPed1701D

[DavidM]

Hi guys, thank you all for your answers. I definitely learnt a few things!

BTW when I said 25 kph it's purely gut feel, I didn't look at the speed. It happened in the blink of an eye as you can imagine. I was about to overtake my wife who was riding an electric scooter in front of me! She never goes beyond 20 kph for sure... but yes, I put some pressure on the pedal, and that plus low battery created the problem I suspect! My wife said I was lucky I was not going too fast but as I was accelerating, I felt differently. 

Now I know it can happen! As any rider of EUC you always think about what would happen in case of a sudden breakdown, and that's what I experienced... I think I have been very lucky this time. A bit more than a year ago I broke my wist falling with a Ninebot. I wasn't skilled enough. I know that the same accident would not happen to me now, with my current mileage. An accident can still happen to me of course. But I had never experienced pure shut down of the wheel during a ride so far!

I will definitely adapt my riding better to the situation. I will also observe the behavior of the wheel much closer now. Like the few moments where I was certain it was on when pushing the trolley and as I stepped on the pedals to go I realized it wasn't.

 

A few takeaways from my side if I understood well:

- ride with battery fully charged if possible; under a certain level the probability that such issue arises is much higher. For instance, to try to empty the battery before the next charging is apparently not a good idea, it seems better to charge it to full each time you can

- do not hesitate to change the battery if behavior of the wheel changes : battery health is your health ! I wonder on which mileage we should think about renewing the battery in any way... maybe around 2000 km?

- I was used to my wheel responding very well and give me the torque I wanted, I will now treat it a bit more gently - French Saying: "he who wishes to travel far takes care of his mount"

 

8 hours ago, who_the said:

The V8 is an awesome wheel. But it can be overleaned. I have done it twice myself (both with no warning), and have witnessed it as well. I've known it to happen during initial acceleration and also at cruising speed. An overlean is not an indictment of one's riding ability, or a sign that your wheel can't be trusted. It's merely your forward momentum asking for a bit more power than your wheel can offer.

Good summary Who_the, and thanks.

[WARPed1701D]

Just to expand upon your "takeaways":

Litium Ion batteries do not have a memory so you do not need to fully discharge your wheel before recharging (in fact this is bad for the battery life span).

To prolong life of the battery when you charge your wheel consider the ride you expect to take on it. For your V8 if you are thinking a 10 mile ride then I would not charge it fully (maybe to 90% capacity). Likewise to prevent cutout on a downhill section right after charging also do not charge to 100% as you need to leave some capacity for the batteries to absorb the regenerative charge.

If you do not regularly charge to 100% then do so every 5 - 10 charge cycles leave the charger on for an extra hour or two . This ensures all the cells get a balancing charge and then no one cell should be the "weak link in ther chain".

Under standard full discharge/full charge conditions you should expect about 500 charge cycles from the LG MH1 batteries (0.5C charge/discharge) rates before the manufacturer considers the battery at the end of life. We do pull more then 0.5C during certain conditions so I'll reduce the count to 300 to be safe.  On a V8 with about 22 mile range this is about 6600 miles but other things affect battery aging. Leaving the battery fully charged between uses can drastically age the battery. A fully charged litium ion battery sitting at room temperature can lose 20% of it's possible capacity in just 3 months. So, if you know when you want to ride leave the battery at about 30% power and just charge it before you want to ride (allow a 30 minute rest period after charging before riding).

[Chriull]

1 hour ago, DavidM said:

 A few takeaways from my side if I understood well:

 

- ride with battery fully charged if possible; under a certain level the probability that such issue arises is much higher. For instance, to try to empty the battery before the next charging is apparently not a good idea, it seems better to charge it to full each time you can

- do not hesitate to change the battery if behavior of the wheel changes : battery health is your health ! I wonder on which mileage we should think about renewing the battery in any way... maybe around 2000 km?

You will notice once the battery is degraded by lower range and "sloppy" behaviour of the wheel.

as @WARPed1701Dstated with normal full charged to discharged cycles one should get at normal temperatures about 500 full discharge cylces from the battery, which is quite a milage. But then the batteries are not dead - they should still have about 80% of their capacity!

this lifespan can be greatly improved the longer the battery stays around ~30-50% charged - imho the amount of full discharge cycles then could be improved to some ten-thousands... but one takes the fun from driving with no range left by just pleasing the batteries

imho more important is to not discharge the batteries and then let the wheel lay around too long (by the self discharge the charge gets really low until they are irrevocably destroyed) and the second worse thing is to store them fully charged at high temperatures.

also very important is to balance the battery pack regularly by leaving the xharger plugged in for a couple of hours after the pack is already charged!

But looking to treat the batteries right is just one thing - the other imho more important thing is to not accelerate too much at high speeds.

From combustion engines we are used that they get loud if we rev them up to much. We know that we can destroy them by doing this and they really sound stressed if one overdoes this. And one also knows that there is no (real) acceleration anymore at high revs - but it does not matter since one has two or four wheels and nothing happens but one just keeps the speed... and noone would do this - making noise and destroying the engine is just crazy.

electric motors have no problem revving up, one hears nothing - but the torque==acceleration gets less too - so no "internal" warning until one lies flat on the ground. They manufacturers implemented beeps and tiltback as warning, but if one accelerates (leans forward) strong enough this warnings come way to late or even not at all... there is much room for improvement and especially as you noticed this should be mentioned in the manual.

So also with a fully charged new battery in perfect condition every wheel can be overleaned - its just easier with an empty battery...

Overleaning with an msuper its much more daring and suicidal than with an airwheel but still no problem at all...

 

Edited September 18, 2017 by Chriull

[US69]

24 minutes ago, WARPed1701D said:

Under standard full discharge/full charge conditions you should expect about 500 charge cycles from the LG MH1 batteries (0.5C charge/discharge) rates before the manufacturer considers the battery at the end of life. We do pull more then 0.5C during certain conditions so I'll reduce the count to 300 to be safe.  On a V8 with about 22 mile range this is about 6600 miles but other things affect battery aging. Leaving the battery fully charged between uses can drastically age the battery. A fully charged litium ion battery sitting at room temperature can lose 20% of it's possible capacity in just 3 months. So, if you know when you want to ride leave the battery at about 30% power and just charge it before you want to ride (allow a 30 minute rest period after charging before riding).

Just some more expandings:

The battery's are not meant to be "at the end of life" after 500cycles...normally this amount of cycles is said and that then the batterys are down to 70-80% of their capacity.

This goes if you treat them well....and do not to much stress on them.

From nearly 5 years vaping experiences:

On pulling higher amp draws on the cells, they loose a good amount on their capacity right after 30-70 full cycles

(btw: ONE cycle means a completed Charge from 0-100% or for ex.: 2 times 50-100% charging is ONE cycle, also)

This means: That on our usage we can exspect a capacity loss a bit earlier as the announced cycles of 500, also!!!

 

Some more:

The LG MH1  is known as a bad cells for higher amp draws, and i really got no clue why Inmotion chosed this cell for the V8 (with only 2 parallel Systems!!!)

When you draw 10Amp from this cell it Drops directly down 0,6Volts......so at a capacity of 50% the drop is that bad that it goes under 3 Volt!!!

 

Yes, you can argue that the 18650PF and GA from Panasonic used in GW/KS are not better....BUT: The difference is that the V8 only has 2 parallel Systems, the GW/KS wheels have at least 4(up to8) parallel Systems, so the drawn amperage is shared much better! I would have expected Inmotion to use a really high amp draw capable cell like the LG HG2 ...like Ninebot did on their 2 parallel wheel->One E+

 

So V8 Drivers: Beware of (middle to hefty)accelerations when under 50-60% capacity....you will have a good Chance to overpower/cutout your wheel...

As longer as i think about it, this all makes more sense: Longer usage, no full battery, acceleration....it sums all up.

 

 

[Mono]

16 hours ago, DavidM said:

Yes that's what happened : the wheel stopped, it just went off, simply. Conditions were not special, as far as I remember (speed, me leaning, ... nothing unusual)

Then my question again: how would you differentiate between "it went off" and "it lost its torque"?

[DavidM]

7 hours ago, Mono said:

Then my question again: how would you differentiate between "it went off" and "it lost its torque"?

I'd say: being suddenly on free wheel, no more response from the wheel whatsoever. The wheel gave up litterally, no more self-balancing, nothing. It is maybe rethorical, I am not sure.

[Marty Backe]

9 hours ago, KingSong69 said:

Just some more expandings:

The battery's are not meant to be "at the end of life" after 500cycles...normally this amount of cycles is said and that then the batterys are down to 70-80% of their capacity.

This goes if you treat them well....and do not to much stress on them.

From nearly 5 years vaping experiences:

On pulling higher amp draws on the cells, they loose a good amount on their capacity right after 30-70 full cycles

(btw: ONE cycle means a completed Charge from 0-100% or for ex.: 2 times 50-100% charging is ONE cycle, also)

This means: That on our usage we can exspect a capacity loss a bit earlier as the announced cycles of 500, also!!!

<snip>

With the amount of wheels that I have I might charge any one of my wheels ~2 times a month (e.g., it's been at least 3 weeks since I turned on my ACM). So even in your worst case scenario I have a solid two years of riding with any of my wheels.

Another reason that I advocate that we all have multiple wheels 

[CaptainKBLS]

2 minutes ago, Marty Backe said:

With the amount of wheels that I have I might charge any one of my wheels ~2 times a month (e.g., it's been at least 3 weeks since I turned on my ACM). So even in your worst case scenario I have a solid two years of riding with any of my wheels.

Another reason that I advocate that we all have multiple wheels 

SHOW OFF!!! :-)

[Mono]

17 hours ago, DavidM said:

ride with battery fully charged if possible; under a certain level the probability that such issue arises is much higher.

A better way to look at it is that you need to slightly adjust your speed to battery charge status, as @WARPed1701D suggests. 

If you are inclined to understand this further, this post is an excellent source of what is going on behind the scene (you may translate current with torque):

Different battery status limiting the possible driving situations are the straight slanted lines to the right. In these graphs the difference between max and min battery status in limit speed are 6km/h. Limit speed is when you lean in further to accelerate, the wheel has no additional torque left to keep you upright.

Edited September 19, 2017 by Mono

[dmethvin]

On 9/17/2017 at 9:34 PM, DavidM said:

no tilt up, I was not over leaning, no over speed... 

nowhere here it is said there is a risk that the wheel will turn off.

I know the people on this thread may not sound sympathetic but I think we all have been here. Any rider has most likely experienced something similar. Our concern is that you have unrealistic expectations of what a wheel can do to keep you safe and we want you to understand before you hurt yourself. The EUC can only keep you balanced as long as the motor can generate enough torque and the battery can provide enough power. It sounds like your wheel "failed" because it wasn't in the safe envelope of operation as far as speed, acceleration, and battery level are concerned. These are variables that you control.

It's more difficult to determine exactly what happened because you've turned off all the warning beeps and are expecting tilt-back to provide a sufficient warning. That is not a good strategy AT ALL, especially when the battery is low. The wheel requires torque to create the tilt-back effect and if there is no power it cannot do that. If you lean forward, especially aggressively, and there is not enough torque, you will get even further off balance. The wheel can't tilt back because it has no torque left, and you will continue to fall forward until you hit the ground. 

Now it's always possible that your wheel "failed" because there's a loose connection or something. To test that, turn all the warning beeps back on and ride it for a month without pushing the limits of acceleration, speed, and battery level. Does it fail? No? Then most likely you just overleaned it.

[caelus]

57 minutes ago, dmethvin said:

Any rider has most likely experienced something similar.

A cut out?

I have had several cut outs, but only because of very special situation: I ignored the low power alarm on my Airwheel X8 and switched the wheel off an on again to continue for another meters, multiple times. Eventually the wheel cuts out then. But again, only because it is so much used, battery has only ~30% capacity compared to the new state. I did not have the original Airwheel battery pack installed, but a chepo one from ebay. Seemingly, it was a low power cut out from the battery pack circuit. I was prepared that the wheel will give up, but a fall from a cut out is largely different to one from an overlean, throws you totally unexpected with abrupt complete power loss.

I don't know if it is possible to provoke a cut out on other wheels when their batteries don't have a low voltage protection. As far as I understand EUC_extreme here, he had driven his wheel through the limits, had many overleans, but never experienced a cut out (below the max speed). 

[t0me]

Had my first cut-out today.
Accelerated too hard whilst already going quick on a 70% odd depleted battery.   

Lost some bark.   Some new scratches on the wheel.   Lesson learnt.

I was riding with other people and can confirm I did not get any audible warnings.   I didn't feel any tilt back,  and I was riding at about 22km/hr.   Serves me right for trying to catch up with a faster wheel ;-)

 

[Stan Onymous]

45 minutes ago, t0me said:

Had my first cut-out today.
Accelerated too hard whilst already going quick on a 70% odd depleted battery.   

Lost some bark.   Some new scratches on the wheel.   Lesson learnt.

I was riding with other people and can confirm I did not get any audible warnings.   I didn't feel any tilt back,  and I was riding at about 22km/hr.   Serves me right for trying to catch up with a faster wheel ;-)

 

Good for you! At about 35% power remaining on my way home yesterday I had one showing off trying to catch my friend in a car from a stop sign. Lol I was wearing wrist guards and elbow pads and a helmet and suffered no damage. The wheel got a scrape and some padding loosened on my V8.

It took about 30' of constant acceleration before the wheel simultaneously gave a warning, heard the motor 'sigh' and went forward. Got a couple of steps in before I went to wrist guards and shoe toes to a stop.

Turned out it was a different Subaru Impreza and not my friend. . Needless to say, he was more stunned than I was.

[Marty Backe]

2 hours ago, t0me said:

Had my first cut-out today.
Accelerated too hard whilst already going quick on a 70% odd depleted battery.   

Lost some bark.   Some new scratches on the wheel.   Lesson learnt.

I was riding with other people and can confirm I did not get any audible warnings.   I didn't feel any tilt back,  and I was riding at about 22km/hr.   Serves me right for trying to catch up with a faster wheel ;-)

 

It takes time and some accidents to eventually learn that hard acceleration (and deceleration) takes you into dangerous territory. Glad you walked away unscathed from your first lesson.

[Michal]

@Marty Backe Hi Marty, you may help me. I am curious, whether it is possible to go about 27 kph on the V8 without a power cut-off, when the max speed in the app is set to 20 kph (for example).

My point: I would like to set the max speed to 20 kph (so the alarm goes off at 20kph) but I still, I would like to have the possibility going a bit faster than that (let's say I would need to accelerate up to 25kph or even more up to 30kph, ignoring the alarm shouting at 20kph).

Physically, this should be possible as the wheel itself is capable to go at up to 30kph. But is there any software trigger which shuts off the wheel after I set the max speed in the app for example even to 10 kph?

Thanks very much for your reply,

Regards, Michal

[Chriull]

29 minutes ago, Michal said:

@Marty Backe Hi Marty, you may help me. I am curious, whether it is possible to go about 27 kph on the V8 without a power cut-off, when the max speed in the app is set to 20 kph (for example).

My point: I would like to set the max speed to 20 kph (so the alarm goes off at 20kph) but I still, I would like to have the possibility going a bit faster than that (let's say I would need to accelerate up to 25kph or even more up to 30kph, ignoring the alarm shouting at 20kph).

Physically, this should be possible as the wheel itself is capable to go at up to 30kph. But is there any software trigger which shuts off the wheel after I set the max speed in the app for example even to 10 kph?

Thanks very much for your reply,

Regards, Michal

The wheel does not shut off, once one goes faster than the speed set for the alarm. This setting is just for the alarm beeps and nothing else. 

The max speed setting could maybe also be for the tiltback to occur beside the alarm beeps - normaly the wheels can set both speeds seperately.

As discussed/explained here in this topic high(er) speed+high acceleration lead to a situation that has the same result as an power cut off - no more torque left to balance the rider -> faceplant.

[Michal]

13 minutes ago, Chriull said:

The wheel does not shut off, once one goes faster than the speed set for the alarm. This setting is just for the alarm beeps and nothing else. 

The max speed setting could maybe also be for the tiltback to occur beside the alarm beeps - normaly the wheels can set both speeds seperately.

As discussed/explained here in this topic high(er) speed+high acceleration lead to a situation that has the same result as an power cut off - no more torque left to balance the rider -> faceplant.

Thanks a lot for confirming this, it helped.

[dmethvin]

8 minutes ago, Chriull said:

As discussed/explained here in this topic high(er) speed+high acceleration lead to a situation that has the same result as an power cut off - no more torque left to balance the rider -> faceplant.

@Michal this point is really important to understanding how an EUC works. Watch the videos of people testing out the maximum speeds, they are on smooth flat streets. It is very difficult to cruise at the maximum speed, or even close to it. If you lean forward aggressively at 25kph you are likely to end up on your face. If you hit a pothole or even a relatively shallow bump at 25kph you can end up on your face. 

[Michal]

11 minutes ago, dmethvin said:

@Michal this point is really important to understanding how an EUC works. Watch the videos of people testing out the maximum speeds, they are on smooth flat streets. It is very difficult to cruise at the maximum speed, or even close to it. If you lean forward aggressively at 25kph you are likely to end up on your face. If you hit a pothole or even a relatively shallow bump at 25kph you can end up on your face. 

Thanks @dmethvin, aware of this. I only accelerate hard, time to time, from a still position, never pushing hard when at any higher speed than 10kph. I never push hard and close to the physical max(advertised) speed of the wheel. I don't want to fall and scratch my wheel  So far I've done 300 km on my V8 (my first wheel) and only fell once while learning going backwards (the second day). Fortunately, the wheel was wrapped at that time.
Now, I'm only cruising safely and wisely.

My question was only about the alarm, whether it affects the real speed limit of the wheel or it only drives the tilt-back and the alarm for the speed awareness.
I got the answer now from Chriull above

Thanks anyway

[WARPed1701D]

Unless I've been missing something for a long time then there are no speed alarms on the V8. You set max speed and at that speed the wheel will tilt back making going faster very difficult /impossible. I've never seen an option to have the wheel just sound an alert at a preset speed but allow you to ride through it. 

If you use wheellog then you can have your phone (or Pebble watch) buzz at preset speeds but this is not an alert from the wheel speaker itself.