DIY Yuba Mundo BMC V3 48V died mid ride

[beoutside]

I built this bike up from a frame last year and thought I finally had the bugs out.
BMC V3 Hub 48V 1000 W Used
Lyen Controller
CA 3
twist throttle
3 speed switch

I just pulled this bike out for the new season, it charged to 54V ( full for my battery) and started up once I reconnected everything.
At the end of last season I was just figuring out the CA but seemed to have it running smooth and also with in the pedal speeds that suited the three settings.
I had a good twenty rides in no issues except for configuring CA with three setting switch.
1) set for starting and town, if I pedaled more then 10 mph the motor cuts out.
2) set for Bike Path 20 mph
3) 30 mph... I am late picking up kids.

I have quite a bit of experience building bikes , limited electrical experience, no ebike experience.

On the first ride into town this season the motor cut out mid ride
I checked my connections and they seem fine, also checked battery charge fine

There is no motor noise/function in any speed setting or any throttle position.

The hub moves fine by hand and still pedals fine

I have contacted Edward Lyen and he is a great help but need to learn more about how these entire systems work.
We are working on diagnosing the problem.

What I have checked

With My fluke I have 54 V to controller
While plugged in I have 11.88 V DC coming off my main Blue, Yellow, and Green larger Gauge wires running to the hub. ( PLease explain this to me) This does not change when I change the 3 speed setting , this does not change when I have the throttle full or off .

Testing the smaller wires running from the hub to controller ( Hall sensor) ... All from the controller side...... everything plugged in ....
I have 4.29 V from red to black
from black to blue and turning the wheel slowly in reverse I read 5V to .034 V to 0 V back to 5V
from black to green I read 5V to .034 V to 0V back to 5V
from black to yellow I read 4.81V NOT 5V then .034 V to 0 V then back to 4.81V

also if it matters I have continuity between all phase wires blue,yellow, and green. I have NO continuity between phase and hall wires lg blue to sm blue, lg yellow to sm yellow, lg green to sm green . I have never seen a hub open so not sure what that means .

Any tips?
Also I would love to understand how electrical bike systems run from the ground up, so I'll be better equipped to diagnose problems understanding what electricity/voltage/watts/amps all mean and how they relate to the system and how the systems components relate to each other. Any suggested readings????

Appreciate your time
Donny

 

[beoutside]

From Edward Lyen,
just thought I would through this in to help others leaning to diagnose their ride.
Also to check hall sensors with hub in place Edward sent me a link to this video .
From the three emails you described, I suspect one or more hall effect
sensor(s) is faulty.

A volt meter is required to test hall sensors. I would suggest to get
a volt meter from your local Walmart or Radio Shack. The "most cost
effective" volt meter model would do.

With the controller on and connected to the motor, tap the black and
yellow wire with the volt meter, turn the motor very slowly (in
reverse direction for the BMC motor due to internal freewheel
mechanism). You should see near +5v on & off as you turn the motor.
Repeat with the green and blue wire. (There is a total of 3 hall
sensors inside the motor).

Here is a Youtube video to show how to test it:
https://www.youtube.com/watch?v=efYFOHnXh0E

Feel free to ask if you have any other questions.

Regards,
Edward Lyen

Hello again Donny,

From the two emails you sent, the hall effect sensors inside the motor
seem to be functional. As for the motor main wires (also called phase
wires), they are partially connected to each other internally on the
motor stator, so it is normal to get continuity between the phases.

The next thing I would suggest to verify is the throttle. The to use
another throttle on the controller to see if it works. If you do not
have a spare throttle, you can tell if the throttle is functional by:
1. connect throttle to controller
2. power on controller
3. with a volt meter, select DC voltage reading
4. measure voltage between the green throttle signal wire (positive
red lead on the green wire), and black negative wire (black negative
lead on volt meter).
5. twist the throttle and see if there is voltage variation

Regards,
Edward Lyen

 

[teklektik]

Please see: ebikes.ca "Troubleshooting" page

Although it's not strictly necessary, an ebike tester is a good investment - outfit it with connectors that match your build - (otherwise, be very careful - alligator clips are a sure means to get shorts...). Here's a little doc on how to use it: "UsingTheLyenEbikeTester.pdf"

If it turns out to be halls there are several good threads here on replacing MAC halls - same basic motor as the BMC. See my build thread for disassembly/reassembly tips and video links for BMC servicing.

 

[beoutside]

Thanks , I'll talk to Edward about that.
Enjoying learning everything just need more info on what you should be seeing for voltage and continuity in testing everything.
Should you have continuity from your phase wires to your hall sensor wires?
I may need to find some info on these hubs and how are wired/connected.
I am not at the point yet were I understand how these systems work from top to bottom.
Donny
yuba mundo bmc v3 build

 

[beoutside]

Still trying to find out problem of hub motor quitting. Now checking throttle

Hi again Edward
Using my Fluke 77 multimeter ( pawn shop score years ago)
With only the controller plugged into 54V DC , rechecked battery... and the throttle plugged directly into controller, nothing else plugged into controller.
I see
pos to neg , or red to black power on throttle in 0 position I read 4.63 V
green to black it starts at 3.40 V at beginning position and climbs to 3.63V at end position. So thinking throttle fine, but I don't know perimeters.

Appreciate your help!
Also I checked the main phase wires coming from controller while in this configuration
meaning I do not have anything plugged into the controller except power and throttle .
and I have ~ 12V at green and yellow, ~.4 at blue.

I also pulled the covers off the wires leaving the hub and the look good.... which I assume was confirmed by the reading coming back when I tested hall sensors.

 

[beoutside]

Also checking throttle configured back to everything hooked up through CA I get more of a voltage range on the twist throttle .
testing the same black and green throttle shows .8V to 4.8 V as twisting off to full on .

If ~12 V is what I am supposed to read coming from your controller phase wires yellow, green and blue. which I see continuing down my green , yellow and blue. Then I should open the hub and see why the hub isn't responding at all.

Also I just don't understand as you twist the throttle where should you see this at the other end as far as voltage goes and increasing power to hub.
This might help me understand were I am having problems?

Also My hall sensor connectors going into your hall sensor connectors looked sketchy so i pulled them out and reconnected them but still get 4.8V yellow on and off. 5.0 V green on and off and 5.0 V blue on and off as rotating wheel backwards.

As I was testing this the ground that goes from my battery to your controller came unplugged, I was piggy backing this as my tester ground ( Andersen pole connector) by chance I did not notice this at first and read 54 V now coming off a phase wire. So I went back and unplugged the ground leaving just the red power going from battery to controller... this showed 54V coming off all phase and hall sensor wires... I assume that's bad! Hub motor did not respond.

Thanks appreciate it!
Donny

 

[bobc]

"pos to neg , or red to black power on throttle in 0 position I read 4.63 V
green to black it starts at 3.40 V at beginning position and climbs to 3.63V at end position. So thinking throttle fine, but I don't know perimeters."

I'm thinking throttle not fine at all. I know nothing of "Yuba mundo", but my hall effect throttle output varies from about 1.0V to about 4.0V as you twist the throttle. That's on quite a few twist and thumb throttles.
Also I'd expect the "red to black" voltage to be near 5.0V, 4.63 sounds a bit low, but it could be being pulled low if something is faulty.

 

[teklektik]

Seriously dude - stop measuring voltages at random, particularly when you don't know what the proper readings should be. Don't worry about how everything is supposed to work when it's running, you only need to find specific test procedures to determine what's broken - these are very different things...

pos to neg , or red to black power on throttle in 0 position I read 4.63 V
green to black it starts at 3.40 V at beginning position and climbs to 3.63V at end position. So thinking throttle fine, but I don't know perimeters.

Not to be harsh, but if you had read the 'Testing a Throttle' troubleshooting guide on the page I linked above you would know that your throttle is nowhere near 'fine'...

Start by disconnecting the CA and plugging the throttle into the controller to eliminate variables - especially since it sounds like your CA throttle voltage is 0.8-4.8V which is way strange (looks like your CA is not set up correctly).


Here's a 'Why doesn't my bike work?' test procedure for a MAC/BMC from a post a few years back - maybe this will help:

• Here's a bunch of things to test (some sort of dumb, but... ):
  
  • Power up the controller to draw a little of power and probe the connectors:
  • Do you have battery voltage at the battery connector? If not and you didn't first charge the battery when you got it, the BMS may simply have shut down. If no volts, then charge it.
  • Do you have battery voltage on the other side of the breaker? If not, try jumping the breaker - it may have toasted contacts.
  • Measure the voltage across the Gnd and +5v pins of both throttle and/or the hall connectors (red/black).
    • If either one measures 4.5v-5v then the logic supply is good.
    • If voltage is not present on either, then the controller logic supply is either switched off or dead. Check for the small gauge red 'ignition' wire and verify that it's hooked to Vbatt+.
    • If present on only one then the other connector (without the voltage) has a broken Gnd or 5v connection.
• If you got this far then the controller is powered, the logic power supply is good, and the halls and throttle have power.
  
  • Power the controller down and unplug the halls and phases.
  • Use your meter to test for continuity between each of the phase and hall connections and the axle. There should be none - no lead should be shorted to the axle.
  • Spin the wheel backward (so the clutch engages) - it should turn with just minimal drag from the gears - note the level of drag for comparison.
  • Short the Y+B phase wires together and spin the wheel backward - there should be noticeable drag as the dead short loads the motor in 'regen mode'. Repeat for the other phase pair combinations: Y+G and B+G. If any pair does not have drag then there is a broken phase wire.
• If you get this far then the phases and phase wiring are okay.
  
  • Just take a moment to examine the hall and throttle connections for wire breaks near the connectors.
  • With the phases disconnected and the controller powered down, try to rotate the wheel backwards. Note the amount of drag. Now connect the phases and try to rotate the wheel backwards again. The drag should be the same. If there is more drag then you probably have shorted FETs.
    
  • Connect the halls, power up the controller, and using your meter check the voltage from the black hall lead to each of the three hall wires (B,G,Y) individually while slowly turning the wheel backward (so the clutch engages). For each hall, the voltage should switch up and down (0V to 4-5V) about every 2 degrees of wheel rotation.
    • You have to turn the wheel extremely slowly and carefully when testing a MAC because of the 1:5 speedup of the rotor caused by the internal gearing - the hall transition is very easy to miss with a meter. If you are using an auto-ranging meter - lock it to 'volts' range so it won't waste time doing ranging.
    • If this was DD instead of MAC (no clutch and gears), the signal would change 5 times more slowly (10 degrees or so) and the wheel could be turned in either direction to test.
• If you got this far then the FETs and halls should be okay.
  http://www.ebikes.ca/documents/BlownMosfets.pdf
  http://www.ebikes.ca/documents/HallSensorTestingFinal.pdf
  
  • Power up the controller.
  • For a hall throttle, probe the throttle connector and verify that the throttle sense wire varies from about 1v to 4v (more or less) as you advance the throttle from ZERO to WOT. A resistive throttle (Magura) should have a larger range of 0v - 5v (or close to it).
• If you got this far the throttle is supplying a workable input voltage to the controller.
  http://www.ebikes.ca/documents/ThrottleTesting.pdf

If all this worked, then your controller/motor/throttle all should be good - if not then you probably have some other controller issue.

 

[beoutside]

sounds good

 

[beoutside]

Also I was going from what Lyen Controllers described to me. I may have also not done a very good job of describing my analysis.

Tested throttle control from controller directly while CA unplugged by : measuring main red/black on throttle/controller wiring first, voltage 5V, great. Then checking green to ground for initial low voltage~1V climbing to ~4V as twisting to WOT . I did not get these readings but instead saw 3.4 initial V to 3.6 WOT V and sent my controller back per Mr. Lyens advice. Lyen also recommended jumping the connection on the controller side of the throttle to make sure it wasn't the throttle it self, no result.

Previous to this I tested my hall sensors per Justin's recommendation from ebike.ca and Lyens recommendations as well as using his guide for testing the controllers mosfet. Both tested out fine but again how I wrote this out may have been confusing.


Appreciate the info.

 

[beoutside]

From Lyen controllers

I have received your controller and troubleshooted. Unfortunately, the
microprocessor is shocked and a high power capacitor blew. I am not
sure the root cause. I would suggest if you leave the battery with the
charger plug in, it would be best to unplug the controller completely
by disconnect the main battery terminal (or at least one of the
battery wire such as the battery positive). This way, the capacitors
inside the controller will not be charged when the battery is being
charged. Also unplug the controller when not in use. The reason is
because the controller is still in standby mode when it is turned off.

The controller circuit board and two capacitors need to be replaced,
the repair cost is $50. Please let me know if you would like me to
proceed.

 

[beoutside]

I ordered another Lyen controller, problem solved, went with a 12 mosfet vs the 9 mosfet one I had been using, although it only had 30 miles on it I have not received any warranty credit.
I also ordered a BMC controller 12 mosfet, directly from BMC.
Thanks for all the help .Donny