Intermittent power on TSDZ2

[nesdon]

I have a 48V TSDZ2 with an 850C display and a Hailong Shark style battery with a throttle running stock firmware from Eco Cycles. When testing on the stand my motor gives a small burst, then drops to near zero. I don’t feel any power when starting off, but once I reach 12-15 mph it starts working normally.

At first it seemed like a bad power plug, but I cleaned, tightened, and checked the connections with no change, and then discovered it worked at speed. Any ideas what could be causing this?

 

[DingusMcGee]

If you suspect the wiring, finding the location of the open circuit (loss of continuity) can be difficult because the way in which we set up the probes pushes the circuit gap together. Twice I have traced the erratic power loss to a cracked solder joint on the 3 phase power plug of a Cyclone 6k.

The first incident was a mystery for a while as every meter test confirmed continuity. I suspect I was pushing the cracked solder joint together with the probes and insuring continuity. Apparently high speed vibration when running kept the crack close enough most of the time for sufficient electrical power transmission (maybe intermittent). This situation works, after all, the normal power feed is pulses. On an earratic stop in the field I pulled on the blue motor phase wire and held the other side of the plug with the other hand. The wire readily came out of its socket. Since the blue wire resoldering job this ebike has not exhibited erratic running.

The second incident was on the other Cyclone 6k bike at the same plug. The erratic running occurred so seldom that no attemp was made to locate the source of the nuisance. Then while pulling a steep trail hill the motor quit. The CycleAnalyst showed max amps at 79.48, max rating is 80amps. One of the phase wires easily pulled out of the plug -- poor job of soldering or just too hot? I eliminated the plug and the erratic halting has not reappeared.

The Cyclone compact phase plug has the three wires very close to each other -- think to much adjacent heat transfer? Also resoldering wires to it is a task as it is hard to heat one joint without the other solder joints melting.

F.....g lousy design/plug. E-contact lube doesn't help.

Sometimes plugs get minuscule gaps. Electrical conducting greases will often close the space.

Sometimes plugs get contaminated. Airesol sprays applied with brushing may remake a non-working joint.



Too much mushed out electrical conducting grease can create a short circuit -- use miniscule amounts on the Hall Plugs.

 

[nesdon]

I think the fact that it works normally across various loads at speed suggests it’s not an intermittent short. Seems more like an electronic issue.

I also notice a snap of an arc, like a capacitor discharge, for an instant when I connect the battery hot. Maybe it’s actually changing a coil or cap in the motor.

 

[DingusMcGee]

Note: you use the term "short circuit". Most likely you have an "open circuit" situation. The two terms are not synonymous. Generally short circuits heat things or burn 'em up -- Sparks. With open circuits action ceases.

If it is an electronic issue, throw your controller away and get a new one.

"The snap of an arc" -- you are charging the capacitors to fast. Put a 20 watt 2000 ohm resistor in parallel with your power connect switch.

 

[nesdon]

Indeed I misspoke. It acts more like an intermittent open. But I would expect a poor connection to come and go either by something flexing, or by changes in voltage or current that might allow it to arc across the gap. That it always conducts as soon as it reaches 12 mph, across the full range of loads, but stops and never conducts the moment it falls under 12 mph regardless of load or power level suggests something else. Perhaps even software. Why should the controller even react to a value like wheel speed?

 

[ilu]

Mysterious problem indeed. A simple misaligment of the speed sensor could cause this kind of behaviour, if the speed reading would be erroneus at lower speeds but more stable in higher speeds, but then the display would show random speed readings as well (which could shut off the motor when speed exceeds the top limit).

I would also suspect a software fault, do you have another display you could try? Or a spare display cable, on which you could connect the Vin and P+ wires according to this, as that would make the controller to use 'default' values at full power.

 

[nesdon]

I haven't checked all the low-voltage connectors. I suspect the speed sensor may work by generating a voltage rather than modifying resistance. If so, its connector pin may only conduct when that voltage gets high enough to push through the whatever is compromising the connection, and that may allow other signals.

I do live in the NY and my bike is often ridden in rain and snow where the streets are liberally salted. The connectors, with their very fine wire contacts, along with the force required to close them, always makes me concerned I may bend a pin, so I avoid opening them whenever possible. I think I will clean and check them all, reflash the firmware while I have them open, and see if that fixes it.

 

[amberwolf]

Based on your description it is not intermittent (meaning it randomly comes and goes), it is a very specific lack of operation below a very specific speed. That greatly limits what could cause it, and connections are unlikely to be the cause. Id' recommend changing the title of your thread to match that of this post, to get more accurate help / responses.

You don't say if this is a new problem (and exactly what happened between the time it worked and the time it didn't) or if it has always existed, but if the latter, then it is probably a setting in the system, either corrupted or set to disallow assist below a certain speed. (usually that kind of restriction is the other way round, to prevent assist *above* a speed, but...)

If the former, you'd need to list events that occured between the time it worked and the time it didnt'. Being a fairly dramatic kind of change, it should be easy to remember when it started and what happened at that time. Then you could work logically from those events to see if any of them could possibly have affected anything on the system that could then in turn cause your problem.


The spark you get at battery connection is normal when you connect a voltage to a load like that. it doesnt' charge anything in the motor (because that only gets power when it is being commanded to spin) but it does charge capacitors in the controller.


Wheel speed sensors on middrive ebikes simply use magnets on the wheels (usually on the spokes) and a sensor on the frame; the sensor is turned "on" (usually grounded) by the passage of the magnet. The controller sees a pulse for every magnet pass, and then based on the wheel size set up in the display/controller, it counts wheel revolutions to determine speed, then modifies it's behavior based on whatever settings you have chosen regarding that. So no, the sensor doesn't generate a voltage in the manner you're thinking, so it wouldn't have the kind of problem you would be checking for.


Also note there are a number of TSDZ2 threads, some of which may have info on similar problems to yours, if you haven't already read thru them. This is a link to all threads with TSDZ2 in the title; it's unlikely that they are all relevant, but some certainly could be.
https://endless-sphere.com/forums/search.php?keywords=tsdz2&terms=all&author=&sc=1&sf=titleonly&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search

 

[nesdon]

Well, intermittent does not mean random, it means "stopping or ceasing for a time; alternately ceasing and beginning again" so this time I did not misspeak, but your suggested title is much better, thanks.

The etiology of the problem is that I turned it upside down to change a tire, then when I got on to ride, it had no boost. I came back, and put it on the stand and observed that the throttle would start the wheel for a moment, then continue to run slowly. I thought maybe the upside down jostling had dislodged the battery plug, so checked it and the inline bullet connectors. It seemed to to repeat the bursts of boosts when I manipulating the power connectors while the throttle was depressed, but rather than modulating the current through a poor connection, I now think it was just repeating the initial bursts everytime it remade contact.

I rode it again on a bit of an uphill route where I was running in a lower gear, so never got over 12 mph, and it was on the way back that I finally got up to speed and had the boost kick back in. I took a few more test rides and confirmed the speed correlation.

With the motor off and no throttle or crank torque, it seems there shouldn't be a load per se to arc. However, I once had a huge 50 amp variac that could blow a breaker just from the inrush to charge the primary coil. This little snap of an arc more resembled a capacitor discharge than the arc of a load or inrush to a coil, but, as I said I was just guessing. Hoping to do some work on it tomorrow and will report back.

 

[amberwolf]

The etiology of the problem is that I turned it upside down to change a tire, then when I got on to ride, it had no boost.

Then the most likely causes are a mechanical issue such as the wheel-mounted speed sensor magnet getting moved, or the frame-mounted sensor itself getting moved, especially if these are on the wheel that was serviced. Note that if the magnet is loose on the spoke, just a tiny bit, it might move "inward" a hair and not line up with the sensor, but at a high enough speed, it would be forced outward and line back up with the sensor again.

If this is the problem, then it will probably read the speed incorrectly or erratically until the magnet is realigned. If there are no problems with the speed readings regardless of the speed, then this is not likely to be the problem.


It could be a speed-associated setting (corrupt, or accidentally altered), but that's much less likely, unless there are no problems reading speed.

Note that if the system requires a valid speed reading to operate but isnt' getting one, you could easily get a burst of operation when the throttle/etc is applied, then nothing more until it does get a valid speed reading.

With the motor off and no throttle or crank torque, it seems there shouldn't be a load per se to arc.

Capacitor inrush is what causes this battery-connection spark in ebike systems that don't have the battery turned off (at it's BMS, or it's keyswitch, etc) during connection. (or a disconnect switch somewhere between battery and controller that is still connected).

 

[nesdon]

I keep my bikes at my daughter's home where I used to live, as my third floor walk up apt has nom place to store them. I charge my car there as well, so the bike is my way top shuttle back and for5th to pick up and drop off my car, meaning I often am not near the bike when I am posting here.

I have the bike on the stand again, and to my surprise found the magnet of the speed sensor twisted sideways. I realigned it and it seems to work fine now, Doh!! Pretty lame of me to not check it first, especially that it's just a glance, but I assumed (making an ass of me) that if I was getting a speed reading, it must be okay. Double Doh!

Now treat I've got Bootcamp working on my Mac, and set up to reflash the firmware, I'm thinking of reinstalling the OSF. I went back to the stock due to a fault where the OSF seemed to get stuck for few revs calculating a new power point after I stopped pedaling to make a shift (being an IGH guy, I've never felt the need to use a shift sensor as I my habit is to stop pedaling before I shift).

I recall reading some revelations about what might be causing this, but wonder if a fix was included in the current version. I know casainho had moved on to wireless and displays, but that other folks were also involved, but the newest version on github looks like 0.57.3 and is 2 years old. Does anyone know if that pause issue was resolved in this build?

 

[Blacklite]

Try MBrusa’s firmware - there is adjustable deceleration as a setting for when you stop pedaling.

Also will help you diagnose the possible speed sensor issue as you will get useful error messages, and the firmware is far less sensitive to magnet location on the sensor as well.

https://github.com/emmebrusa/TSDZ2-Smart-EBike-860C

 

[Waynemarlow]

Many of the intermittant speed problems can be a very simple thing on the stock TSDZ2's, its been written about a 100 times already on the main thread but just to repeat it once again, you have your magnet to close to the speed sensor. At least 10mm clearance, many of us run out to 15mm clearance.

 

[nesdon]

That's odd data. My magnet has shifted a bunch of times, and the only result, prior to this, was that when gets over about 10mm or so the speed readout just stays at zero. I return it to about it 5mm and it reads accurately (more or less) again. This time it had rotated so it was perpendicular to the pick up. I turned it back and all fixed.

Are you saying that this same symptom: no boost until high wheel speed, happens when yours is at 10mm and returns to normal at 15mm, with the speed readout working throughout? I've seen videos of folks running these on the bench with no speed magnet at all.

Hard to understand why the speed pickup should be able to cause my symptoms at all. I guess there must be code to limit the top speed that is interpreting the pick up data in a different way than the speed read out. Strange it should trigger the high speed limit when the display is reading 5mph.

 

[nesdon]

waynemarlow, can you give me some links to these posts? I made some searches before the original post and after your reply as I'm still unsure of the parameters of the issue and would love to understand it better. I'm not even sure I could find a position on the chain stay and spokes where the sensor would get 15 mm of clearance from the magnet.