DarknessBot pwm inaccuracy with veteran Sherman

[Monoxy]

I connected DarknessBot to my Sherman and realised that the app was beeping early, at like 58-60km/h. I then set the beeps on DarknessBot to 80% and noticed that the app still started to beep before the actual euc. Since the Sherman beeps at 70%, DarknessBot must be inaccurate. Anyone else experience anything similar?

[Chriull]

1 hour ago, Monoxy said:

I connected DarknessBot to my Sherman and realised that the app was beeping early, at like 58-60km/h. I then set the beeps on DarknessBot to 80% and noticed that the app still started to beep before the actual euc. Since the Sherman beeps at 70%, DarknessBot must be inaccurate. Anyone else experience anything similar?

PWM duty cycle is not reported by sherman but roughly estimated by darknessbot. So nothing to really rely upon but just to be taken as a hint.

[littlebigmac]

I just picked up the Sherman max and also was able to trigger the 70% pmw alarm in darknessbot at around 58 km/h. Has anyone played around with the “PWM correction” setting in darknessbot? I’m wondering if there’s a way to dial in the “estimated” value a bit closer to the real world value somehow. I ride with a full face helmet and use a Bluetooth headset for speed/pmw alarms as it’s easier to hear over wind/traffic noise (which works great on my 16x).

Edited April 3, 2022 by littlebigmac

[Chriull]

57 minutes ago, littlebigmac said:

I’m wondering if there’s a way to dial in the “estimated” value a bit closer to the real world value somehow.

One can get the real pwm values by now with 

 

[littlebigmac]

1 hour ago, Chriull said:

One can get the real pwm values by now with 

 

Oh sweet! I’m going to have to look into this. Thanks for the tip!

[Xodarap1]

Tonight on the Shermax, during my 14.8 mile commute in to work I heard darknessbot in my bluetooth earpiece say power exceeded a few times periodically.  Sometimes when hitting moderate bumps at 37 mph, sometimes on smooth pavement at 37 mph.  Tire pressure: 30 PSI

Highest temp during the ride was displayed at: 114.6 F

My wheel is always charged to 100% when I leave from work or home.

Once I was able to review things, it seemed to happen 7 times.. each time my speed went over 38 mph.  I was riding into the wind but on level ground most of the trip and the warnings happened during the first few miles before the battery was even down below 98%. 

*Trip info when arrived: max speed: 38.3 mph, Voltage: 92.72, Temp: 113.4 F, Battery: 73%, 
Average speed: 32 mph, Remaining mileage: 92.4, Total miles on the wheel: 386.9 Mi

I was at my usual riding setup with backpack for a total of 243 lbs.

My darknessbot settings:

By speed: 42, 43, 44 mph

Smart alarms is ON

By amperage:  145, 148, 150 A

By power: 4800, 5500, 5600 W

By PWM: 80%

I had current readings over 88, 7 times: 115, 104, 106, 113, 141, 120, 121

I had power readings over 4800, 7 times  * One was spiked at 8,212 

I got no warning beeps from the wheel itself, although I did get a speed exceeded warning twice when I hit 38 mph, but I guessed that was mid trip and was the PWM at 80% in darknessbot warning me.  But, I really don't know.

Was I in any danger of it cutting out?

If not, would it be still safe for me to adjust the darknessbot settings higher for amp and power?

Suggestions?  

Sorry for the book.  Any help or comments appreciated.

Steve 

 

 

 

Edited May 23, 2022 by Xodarap1

[Tawpie]

7 warnings and 7 overcurrent/overwattage but no PWM. I'd say you were probably ok, Sherman runs quite a bit faster than 38 without incident.

If it's working properly (big if), PWM is sort of the 'master alarm' for how close you are to the wheel not being able to keep you upright. Current and wattage are related to your battery voltage so they're kind of redundant—I think they're bragging fodder more than any kind of usable warning.

I wouldn't feel bad about raising current and power warnings, or even turning them off so you don't get nuisance alerts. PWM should be your one-stop "about to overpower" warning.

One thing interesting is you thinking you might have gotten current/power warnings on bumps—I think we underestimate how much surge power is required to hold balance through a bump. When my Mten cutout on me, I'm absolutely certain it was because I hit a bump and that overpowered the wheel. No power pads, was maintaining speed not accelerating. Just a bump was enough to make it throw all the toys out of bed. Both my 16X and S18 will beep the safety margin alarm hitting a bump while moving briskly on a not full battery. Bumps+high speed are not a good combination, especially with high capacity instead of high power battery cells.

Edited May 23, 2022 by Tawpie

[Xodarap1]

Thank you very much for taking time to reply.  Your reply was great.  

I'll just run the highest, 3rd alert and disable the others.  I should hear the PWM in my bluetooth earbud.  I do wish that there were separate volume settings in darknessbot for both wheel alarms and music via spotify.  I'd prefer the wheel alarms to be twice as loud as what they currently are, or at least louder than the music level.  If I raise the volume to hear the alarms better, my music would make me deaf in no time :-)

Yup, the bumps definately set off the power exceeded warnings and I was just holding speed when they sounded.  Bumps are no joke and they do take a lot of extra surge power.  Respect the beeps and the bumps :-)

Thanks again! 

Edited May 23, 2022 by Xodarap1

[Xodarap1]

I"m adding this update in case this might help someone else in a similar situation..  I made some adjustments in darknessbot and did the commute again:

By speed: 43, 44, 45

Smart alarm is ON

By amperage: 160 A

By power: 6000 W

By temperature: 205 F

By PWM: 80%

* Same route, same outside temp (61F), less wind.

*Trip info when arrived: Distance: 14.7 mi, trip time: 29:42, max speed: 42.6 mph, Voltage: 93.52, Temp: 109.6 F, Battery: 76%, Average speed: 33.2 mph, Remaining mileage: 98.9, Total miles on the wheel: 419.2 Mi

 I only had one "power exceeded" warning when hitting a bump at around 37 mph.  I had one "speed exceeded" warning at 42 mph.  Thats it.  The wheel still felt good and stable during the commute.  I didn't face slide, so that's always a plus