miniPLUS Downhill Lean-Back into REVERSE V1.1.7

[Michael1953]

Beginning with Main Board Firmware V1.1.7 (thru the latest V1.2.0) ALL serial nos miniPLUS - when traveling downhill (ANY Slope, ANY Speed except DEAD-slow) will abruptly start Squawking, HARD Tilt-Back (or Lean-Back) - grinding to a COMPLETE STOP - THEN REVERSING back UP the hill 4-12 inches !!! THEN Releasing control back to the Rider - IF the Rider has managed to remain on-board thru this ordeal. A Novice rider CAN NOT - took me 12+ such REVERSE UPHILL experiences to learn how to thrust-hands-forward, have 'sticky' shoes on so I don't slip off backwards...

I put nearly 200 miles on my original miniPLUS (purchased 13 months ago, serial under 100) - had Firmware V1.0.8 - rode these astd slopes daily with NEVER the slightest hint of this OUT-OF-CONTROL DOWNHILL-REVERSE.

Then Updated Firmware to V1.1.7 and IMMEDIATELY this DownHill LOSS OF RIDER CONTROL about 5-seconds - HARD TiltBack - STOP - REVERSE UPHILL SEVERAL INCHES - then Squawking stops and Control is Returned To Rider.

Believing my miniPLUS was DANGEROUSLY BROKEN I decided to SELL IT FOR SCRAP. And purchased TWO NEW miniPLUS mid-April 2019.

Both arrived with Firmware V1.1.7 - BOTH SUFFER SAME DANGEROUS DownHill TiltBack-STOP-REVERSE !!!!!!!!!!!!!!!!!!!!!!

Ninebot Rep says "NEVER heard of this".   I suspect MANY / MOST? miniPLUS owners reside / ride in FLAT TERRAIN - so NEVER suffer this V1.1.7 DANGEROUS DOWNHILL MALFUNCTION.

I tried ALL settings (in/out of Learner Mode - Auto-Steering Auto-Ride ON/OFF) Nothing changes this DownHill Squawk-TiltBack-REVERSE behavior.

UpDated Firmware all three (SN under 100, SN under 600, SN under 960) to Main Board V1.2.0 and NO CHANGE - Downhill Danger persists.

Now Ninebot Rep says "THIS IS NORMAL". uh......

Latest demo video:
"miniPLUS DownHill AUTO-REVERSES 6 TIMES NO CONTROL"
https://youtu.be/9-2acpdt3C0

previous attempt
"Ninebot miniPLUS OUT OF CONTROL DOWNHILL TiltBack-STOP-REVERSE 5 in 90 Seconds"
https://youtu.be/-wwPB4HV2XU

first video:
"Segway Ninebot miniPLUS mini-PLUS DOWNHILL Lean-Back STOPS FAULTY V1 1 7"
https://youtu.be/BooqMrP3LUc

Anyone else who DOES NOT live in "FlatLand" suffering this? THREE out of THREE IS STATISTICALLY RELEVANT !!!!!

(Michael1953 now has about 2000 miniPRO miles and 240 miniPLUS miles - and $6000 dental work ;-)

 

[jojo33]

Me too#

Two month ago  I had an accident in a descent, the PLUS no longer answered,
This new alarm beep that I did not have before happens every time I leave home with the battery full, I have a small descent, and it's the same braking with an alarm beep
That the Mini brakes downhill is normal ,

but not lose control 

2 hours ago, Michael1953 said:

I tried ALL settings

Try Parameters>sensors> balance , look your Mini inclination, default value is at -0,8

 when you adjust the balance, look the body, the body leans forward (all in poisitive values) or backward (negative value), it reduces the TiltBack, try differents/several inclinations (in positive), make a ride test for each and keep in mind the best inclination value

I think Ninebot added a security alarm for downhill situations, not to go too fast
except that I had the biggest accident in 3100 MILES/5000 km because of this "precaution" of Ninebot

2 hours ago, Michael1953 said:

Ninebot Rep says "NEVER heard of this"

Always, Europe or US, they really dont know nothing about their products and really dont care about their customers

[jojo33]

@Michael1953

After contacting two hours ago,  , I just received an answer from Ninebot China engineer Wang (Ninebot chief N°2)

Please could you make a screen video record (like apk az record etc...) of the app during a similar situation, this show a pop up alarm with a code

Also, about a full charge battery, but in my case happen with or without full charge battery

Please below, Mr Wang's answer

"Hello Joris,

Many thanks for the feedback.

 

Is the MiniPlus fully charged before you ride it downhill?

If yes, the machine will get regenating charing from downhilling; and charge a fully-charged battery, will trigger over-charge protection and the machine will try to inform the rider to get off ASAP.

 

If not, pls try to connect the smartphone app and replicate the situration when it tilts back, to check out what is the alarm exactly is(There will be popup window on the APP screen when an alert triggered).  If possible, pls send me the screenshot of the APP alarm popup box and our technical team will find out what happened.

 

Thanks again and best regards,"

Edited May 6, 2019 by jojo33

[jojo33]

Well i just made a test, actually it happens when it's fully charged,

Regarding my downhill accident, surely my MINI PLUS had to be 98/99% loaded

(riding 600 meters from a fully charged battery- Battery level around 98%- stop MiniPlus during 40 minutes- battery level increase- downhill good speed and accident without control with overcharge and superbad tiltback )

But anyway, it's still dangerous to be out of control downhill, if there is a car that closely follows the rider, so it's dangerous

Edited May 6, 2019 by jojo33

[trevmar]

Sounds like the electronics does not remain stable with temperature. Perhaps as the battery cools, the voltage being sensed rises (due to temperature dependence of voltage sensor). That would be a pretty easy coding/hardware error to make. Now as to why the new firmware version suffers and the old one doesn't, it is just another sign (to me) that the original guru(s) who write the basic firmware for the MiniPRO have long since found better jobs, and the current team is essentially incompetent.

If I had coded that firmware I would not be asking for error-msg-screenshots, I would be replicating the condition you documented, and making sure I understood what could possibly be going wrong...

Edited May 6, 2019 by trevmar

[MetricUSA]

I don't have update on my pro and it is doing this extreme stop going downhill, but on a topped up battery only, it is because of high voltage going in to battery... Doing a swaying motion downhill forces current out of battery not into it....

[mrelwood]

That is normal behaviour on any EUC, and a well known limitation of regenerative braking. The energy from the braking goes to charge the battery, and if the battery is full, it will indeed trigger the overvoltage warning. It sounds like the newer firmware has a more cautious voltage limit for the overvoltage warning.

I don’t remember wether the MiniPro user manual warns about not riding downhill on a full battery, but on many EUCs it does.

If you always start your trip going downhill, either stop the battery charge before the battery is full, or ride on level ground or uphill for a few minutes first.