Magic Pie 4 with Magic Pie 5 controller only half speed

[Timtama1]

We replaced the throttle and wiring loom on a Magic Pie 4 with a 5 controller and the motor will only go half speed now, tried a different throttle and it goes a little bit faster but not like before, the wiring loom is one that has coloured ends so could it be the loom or has something happened to the controller which is just a coincidence? The controller has had the flash update applied. Any help would be awesome!

[Bikemad]

Hi Tim andto the forum.

As changing the throttle affected the speed, it sounds to me like the controller may have a weak +5V output which supplies the motor Hall sensors, PAS Sensor, Bluetooth dongle and the throttle Hall sensor.

Check out this post for further information on checking the actual voltage on the +5V circuit.

As your wiring loom has had to be replaced, is it possible that the problem with the original wiring loom may have somehow shorted and/or overloaded the +5V output causing damage to the +5V regulator in the controller?

Alan

[Timtama1]

When I say the speed is in half, it does everything it can to stay on 20klm/h, the lcd display shows 1000w used when accelerating up to the 20 but then it uses less watts when at 20. When going downhill it won’t use any watts at all. The wiring loom was replaced due to running on the front handlebars and freying. It’s like it has a speed limiter now

[Timtama1]

Tested the 5v and it is normal not under voltage so I’m not sure what the problem is then. Might just have to get a whole new wheel and kit

[Tommycat]

Might be worth checking the output of you hall sensor throttle just to be sure... See this thread for particulars.
https://electricbike.com/forum/forum/kits/golden-motor-magic-pie/70584-guide-to-hall-sensor-throttle-operation-testing-and-modification

If you've got over 3.6 volts output, a couple things come to mind.

Have you done any controller programming? As they can be adjusted to minimize top speed.

Are you using a BAC-601 display made for a version 4 controller?


Regards,
T.C.

[Bikemad]

Hi Tim,

I would first try disconnecting the LCD display, pedelec sensor (if fitted) and both brake switch connectors to see if it has any effect on the maximum speed.

If it makes no difference, and the +5V output is still correct, is it possible that you have somehow set the Maximum forward speed (rpm) setting to less than 360~380rpm?

Please double check the controller settings to make sure everything is still correct:



If all the settings are as they should be, and the controller was flashed with the correct MP5 firmware, I think it could be one of the following:

• a faulty throttle
• a wiring/harness fault
• a faulty controller
• the wrong BAC-601 LCD display unit (As T.C. has already mentioned)

I would start by removing the controller and disconnecting the Yellow, Green and Blue Phase wires (making a note of where they were connected).

Use the positive voltmeter probe to measure the voltage on the green throttle wire connection in relation to battery - (Ground):


With everything connected (except the Phase wires) the voltage should be between 0.8V and 1V with the throttle released and must go above 3.25V with full throttle applied to obtain maximum rpm.

If the throttle signal voltage goes above 3.25V with full throttle applied, then the controller has probably been damaged internally when the wiring loom chafed against the metal handlebars.
However, if the voltage is below 3.25V with full throttle applied and the +5V supply is still showing ~5V on the white +5V terminal, then the problem must be either the throttle itself, or a partial short circuit (or poor connection) somewhere on the wiring between the controller and the throttle unit.

Alan
 

[Timtama1]

Thankyou very much Alan, would replacing the controller fix this issue?

[Bikemad]

Would replacing the controller fix this issue?

Might be worth checking the output of you hall sensor throttle just to be sure... See this thread for particulars.
https://electricbike.com/forum/forum/kits/golden-motor-magic-pie/70584-guide-to-hall-sensor-throttle-operation-testing-and-modification

If you've got over 3.6 volts output, a couple things come to mind.

Have you done any controller programming? As they can be adjusted to minimize top speed.

Are you using a BAC-601 display made for a version 4 controller?


Regards,
T.C.

If it is still slow with the BAC-601 display unplugged and the Maximum Forward speed (rpm) set to 360 in the software settings, and you've confirmed that the throttle signal voltage is higher than 3.25V when full throttle applied, then replacing the controller should hopefully cure the slow top speed problem.



Alan