MSX 84V can't blow a mosfet? WRONG!

[Hansolo]

controls battery voltage with a voltemeter to compare with the value under WheelLog

[The Fat Unicyclist]

On ‎7‎/‎25‎/‎2019 at 8:33 PM, Seba said:

With WL you are always notified by three distinct beeps (each per speed alarm) and "Slow down" message.

Ooohh... Would it be difficult to ad the option to load different audio tracks for the messages?

Or perhaps have the option for celebritary voices (such as @Marty Backe or @Rehab1) telling you to "slow the hell down!"?   

[Seba]

On 7/25/2019 at 6:18 PM, Marty Backe said:

Battery Percentage Not Correct

While performing my formal Nikola range tests I confirmed that WheelLog does not report accurate battery percentages. It appears to be 10 to 15 percent too low. For instance, under load WheelLog was reporting ~0-percente battery yet the wheel had over 15-percent battery remaining.

Every application uses its own algorithm to calculate battery level percentage. Most OEM apps just linearly convert battery voltage to battery percentage. As LiIon discharge characteristic is not linear, obtained percentage will be unreliable especially below 20 % of charge. Many users think about battery level like it would be a fuel gauge and complains that even if they still have 15 % of battery, EUC slows down, starts to tiltback and soon become unrideable.

So WheelLog use more reliable scale to mimic car's fuel gauge. Now you can safely go down to zero and you should still have few miles of margin to ride before wheel become unrideable. So I would say that battery charge shown by OEM apps is not correct if it shows that there is some charge left in battery, but cannot be used to ride. Of course Nikola is a new wheel and it may be needed to adapt WheelLog's algorithm to this wheel, but it need more feedback from users.

[Seba]

On 7/25/2019 at 6:14 PM, Marty Backe said:

Unfortunately the disconnects are so common for me that I'll probably have to go back to the previous version. The Playstore version just works better with my phone. And the voice messages for the current alarms are annoying to me and not practical.

Everyone is different. Looks like other people are really enjoying your version so I'm the outlier 

This is why there are two flavours of WheelLog and anyone can use what fits better their needs and preferences. Euc.world WheelLog was specially developed for long-distance riders, just like me. However it's still universal application and has many features that may suit needs of majority of the riders, Play store version may be preferred by some users and this is why I plan to rename my version so it will be able to have both apps

[EUCGUY]

On 7/15/2019 at 4:13 PM, meepmeepmayer said:

Well, technically it didn't blow a mosfet Just the good old motor wiring melting, as seen in the car push test. Everthing else is just a consequence of that.

I'm surprised it happened so quick. How can you push a car for 6 minutes but a minute on a hill kills it? The way down will already have heated the wires heavily, but even that included it was only a short time, wasn't it?

perhaps a bad bean. on the flip side, i have now designed a temperature guard. demo to be recorded today. hill test. Takes control over leds and sound alarm. 2 modes. "hot" = beep and red flash every 2 sec.  "too hot" = non stop blink and alarm. 

[Marty Backe]

1 hour ago, Seba said:

Every application uses its own algorithm to calculate battery level percentage. Most OEM apps just linearly convert battery voltage to battery percentage. As LiIon discharge characteristic is not linear, obtained percentage will be unreliable especially below 20 % of charge. Many users think about battery level like it would be a fuel gauge and complains that even if they still have 15 % of battery, EUC slows down, starts to tiltback and soon become unrideable.

So WheelLog use more reliable scale to mimic car's fuel gauge. Now you can safely go down to zero and you should still have few miles of margin to ride before wheel become unrideable. So I would say that battery charge shown by OEM apps is not correct if it shows that there is some charge left in battery, but cannot be used to ride. Of course Nikola is a new wheel and it may be needed to adapt WheelLog's algorithm to this wheel, but it need more feedback from users.

I know this is forever debatable. But I want an app that reads ~0-percent battery when I can't ride anymore. When the app says I'm at zero but I can still ride for 5-miles, that's not useful to me. But everyone is different, I understand. 

59 minutes ago, Seba said:

This is why there are two flavours of WheelLog and anyone can use what fits better their needs and preferences. Euc.world WheelLog was specially developed for long-distance riders, just like me. However it's still universal application and has many features that may suit needs of majority of the riders, Play store version may be preferred by some users and this is why I plan to rename my version so it will be able to have both apps

Yeah, I guess I'll go back to the Playstore version. It's just more reliable for me.

[Seba]

13 minutes ago, Marty Backe said:

I know this is forever debatable. But I want an app that reads ~0-percent battery when I can't ride anymore. When the app says I'm at zero but I can still ride for 5-miles, that's not useful to me. But everyone is different, I understand. 

It's just impossible to obtain 0 % at zero range remaining, because it vary with load as much as 10 % (and sometimes more). Play store version is no different, it also shows lower percentage than OEM app.

[mrelwood]

My take on the battery gauge is that it would be best to have the same value shown in different apps. After I had learned to interpret how the percentages from the (green) KS app relate to distance, trying to understand the new % scale from DarknessBot was frustrating, so I gave up and only used the KS app.

[meepmeepmayer]

@Seba We had the same discussion in the Wheellog thread before.

I like that your approach is more friendly to newbies. But personally, I 100% want the old style (direct voltage conversion). I know my wheel starts beeping at 15% voltage. Everything the wheel does depends on the voltage so I want to know exactly where I stand. Range left is less important with all the experience one already has.

Could you maybe have an option to toggle? Your "Intelligent Battery Meter (real battery percentage)" or the old "Direct Voltage Conversion"? Then everyone is happy

[Marty Backe]

2 hours ago, meepmeepmayer said:

@Seba We had the same discussion in the Wheellog thread before.

I like that your approach is more friendly to newbies. But personally, I 100% want the old style (direct voltage conversion). I know my wheel starts beeping at 15% voltage. Everything the wheel does depends on the voltage so I want to know exactly where I stand. Range left is less important with all the experience one already has.

Could you maybe have an option to toggle? Your "Intelligent Battery Meter (real battery percentage)" or the old "Direct Voltage Conversion"? Then everyone is happy

PLUS ONE! Thanks for letting me know that it's not just me that wants the reported battery level to match what Gotway hardware does (beeps at 15%). For now I'm back to the old WheelLog again and it's wonderful.

[mrelwood]

After nearly three very long weeks, replacing all motor wiring, replacing the hall sensors, and replacing the control board, my MSX is finally operational again. Felt like three months.

The new mainboard, dated July 2019, still has the mileage counter bug, where lifting the wheel back up after a fall, all ridden mileage for that power cycle resets.

I think I sensed a slight difference in the 35km/h tilt-back though, in that the tilt-back is now constant and doesn’t go away if I go past 40km/h. Although, I didn’t monitor my speed very closely, and since I had some trust issues at first, I might have not passed the 40km/h limit by very much.

The clicky geiger counter style low speed stress growl also might be dampened a bit.

More testing required though, since the wheel felt extremely strange and unfamiliar at first, after three weeks of riding the 16S.

Took me about two dozen km to start trusting the wheel again somewhat. A few dozen more and I’m sure we’re back where we left off.

[Damarafaka]

On 7/27/2019 at 8:55 AM, Marty Backe said:

Yeah, I guess I'll go back to the Playstore version. It's just more reliable for me.

Hi Marty!

Are both versions compatible with the pebble watch?

I thought I could only use the euc version to connect without problems to the watch.

[Damarafaka]

On 7/15/2019 at 4:13 PM, meepmeepmayer said:

Well, technically it didn't blow a mosfet Just the good old motor wiring melting, as seen in the car push test. Everthing else is just a consequence of that.

I'm surprised it happened so quick. How can you push a car for 6 minutes but a minute on a hill kills it? The way down will already have heated the wires heavily, but even that included it was only a short time, wasn't it?

Besides component failure or a combination of factors, it still seems strange how quick wheel collapsed. The MSX seems flawless maintaining very high speeds and the amps don't seem to affect too much in any negative way. But maybe the initial descent had something to do with it. The MSX seems to be quite stressed and uncomfortable during steep descents and am not quite sure, nobody seems to give it importance, the effect this has on wires, mosfets, overall temperature etc. If you combine this with rider weight, 92kg, starting ascent without resting wheel, the stressful slow pace characteristic of these steep climbs and summer temperatures, could give some clue to the causes of the "quick" failure.

[Marty Backe]

3 hours ago, Damarafaka said:

Hi Marty!

Are both versions compatible with the pebble watch?

I thought I could only use the euc version to connect without problems to the watch.

The Pebble WheelLog app (the part that runs on the watch) has not been updated in years. It's the original version.

So yes, any WheelLog phone app is compatible with the Pebble watch version.

[Boogieman]

On 7/16/2019 at 3:12 AM, Marty Backe said:

Wow, and sorry for your loss. I've been there 

Looks like melted insulation that shorted the wires which blew the MOSFET.

Were you monitoring the current? When going up steep hills, I always monitor my motor current. If I have 90-amps going for more than a handful of seconds, I stop immediately. Because I know that even the MSX can fry, as you've just discovered.

Hopefully your hall sensor wires did not get melted too because then it's also a new motor.

@Marty Backe

90 amps for a few seconds? Overheat hill keep amps below 90? 

My tesla reports over 90A all the time (braking hard, taking off, going over bumps) and i have seen peaks at 160A when jumping (wheel spins up in air and when landing on slower ground a spike) and a bit longer 120A when going steep uphill.

Maybe should separate motor wires if that still is a problem on tesla v1.2 they look pretty solid but from above not solid enough (i guess they are at least as beefy on the msx)

Though i dont get the whole idea of separating them, as the cables converge to a tight package in the cable that goes to the wheel (purple area)

The only place i might be worried about is where the cables "bend off" and/or can be mechanically worn by surrounding sharp edges (plastic brackets, washer holding the main board, main board components rubbing on cables a.s.o.)

(Cerise arrows)

I decided to remove the electrical tape that i had used to tie the three cables togehter and instead us velcro to separate them a bit around that area (with soft part of velcro toward cables to minimize rub) and the secure the velcro with some electrical tape to make 100% sure it will not "vibrate apart/open" and cause pieces of velcro bouncing around the electronics ( i even removed a few dead mosquitos that were stuck on the cooling aluminum fin, as the slightest of leading material could cause a short, especially when wet i.e. fresh insects that contain liquid)

Usual "cable collection velcro" from Ali did the trick

Edited August 14, 2019 by Boogieman

[mrelwood]

My favourite trip of unpaved cycleways in the forest includes a few short steep inclines. I had built enough trust after the repairs to take my MSX through the trip, but I had never looked at the amps (tops at almost 160A).

This was with a rider weight of about 205lbs, and I’d say around 13-15• incline. 

Edited August 13, 2019 by mrelwood

[Mike Sacristan]

20 hours ago, mrelwood said:

My favourite trip of unpaved cycleways in the forest includes a few short steep inclines. I had built enough trust after the repairs to take my MSX through the trip, but I had never looked at the amps (tops at almost 160A).

This was with a rider weight of about 205lbs, and I’d say around 13-15• incline. 

Alright now I can stop worrying that I hit 120A on a steep hill. 

[mrelwood]

2 hours ago, Mike Sacristan said:

Alright now I can stop worrying that I hit 120A on a steep hill. 

I’d guess that with your weight on the MSX, there is absolutely nothing you can do that would reach the limits of the wheel or it’s wiring.

But still, I would separate the motor cables  if I were the slightest bit worried. They are originally doubled down and compressed firmly under a clamp. Separating them should allow a decent amount of additional buffer for extreme stress.

[Pavel Karpenko]

On 7/15/2019 at 6:12 PM, Marty Backe said:

Wow, and sorry for your loss. I've been there 

Looks like melted insulation that shorted the wires which blew the MOSFET.

Were you monitoring the current? When going up steep hills, I always monitor my motor current. If I have 90-amps going for more than a handful of seconds, I stop immediately. Because I know that even the MSX can fry, as you've just discovered.

Hopefully your hall sensor wires did not get melted too because then it's also a new motor.

Hi Marty, I just ordered my 84v 1600w MSX, should I too keep it below 90 amps or the 90 apms is for the 100v, thanks.

[Marty Backe]

3 hours ago, Pavel Karpenko said:

Hi Marty, I just ordered my 84v 1600w MSX, should I too keep it below 90 amps or the 90 apms is for the 100v, thanks.

90-amps is a perfect value for the 84v MSX. Only something you have to monitor if you're really riding it hard for long periods, like climbing lots of steep hills.