Hi, I have an e-bike made from a conversion - BafangG310 rear hub motor, Grinfineon 20A controller and a 36 V battery. Recently the motor stoppedworking properly - it seems ok under low power/low loads but makes a ‘knocking’ feeling under higher load and doesn’t deliver any power. I bought one of these cheap e-bike testers from china and the motor itself tests ok. For the controller, the LED sequence on the tester starts out OK for about 10-20 s but then the LED’s go ‘nuts’ (flash rapidly and randomly) and eventually all LED’s just cut out. Note I don’t have a traditional throttle, just a PAS RPM sensor. I am assuming my controller is the issue here? Or could it be the battery/BMS? All voltages on the battery look ok and the 5V indicator on the tester seems ok. Thanks for any help!
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E-bike tester - Funny controller LED response
- Thread starter alfy22
- Start date
Which specific LEDs on the tester are you talking about? Exactly what is the tester connected to, and how, during the test?
What does "starts out OK" mean, exactly?
What specifically happened to the bike between the time it worked correctly and the time it did not? More details are better, as this will help pinpoint where the problem may lie.
What does "starts out OK" mean, exactly?
What specifically happened to the bike between the time it worked correctly and the time it did not? More details are better, as this will help pinpoint where the problem may lie.
Thanks for the reply. So I have the 3 phase wires and the 5 hall wires connected to the tester and I’m spinning the cranks to activate my PAS as I don’t have a throttle. This is the result:
As you can see the LED’s start off by following the correct lighting pattern (as per attached manual) but then go random before turning off completely. It does not seem to be a function of how fast or slow I spin the cranks, rather just time.
The issue just started one morning in the middle of my commute when I was riding along all well and good and then the motor just started stuttering/knocking and I didn’t get any power out of it.
The issue just started one morning in the middle of my commute when I was riding along all well and good and then the motor just started stuttering/knocking and I didn’t get any power out of it.
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So when the tester stops displaying in that situation, it means it isn't getting any signals to display, meaning the controller has stopped outputting, which is what you are also getting while riding.
The randomness is probably equivalent to the part where you get the knocking/etc., and probably means the halls aren't providing the right signals to the controller, so the controller outputs the wrong signals to the motor.
If your grinfineon is like mine, then it has sensorless fallback if you unplug the halls, but if it just gets corrupt hall signals it can drive the motor wrong. If it loses just one hall signal but hte other two are ok, it should be able to still operate in a form of sensored mode, as long as the motor is spinning fast enough though at startups it might be rougher.
If it loses a phase connection but the halls work then the contorller can't tell, so the motor runs rough adn may feel "gutless", and may not start on it's own, might just grind or sit there.
So...the first thing I'd check is the connections between motor and controller, and all of the wiring and cabling especially at the axle exit from the motor, and where it enters the backs of connnectors, etc.
The other thing you can check is the CA's diag screen, one left button push from the main screen. Any letters on the left lower side should stay lowercase. uppercase means that limit is engaging, which means the htrottle output from it to your controller is being modified / decreased / ceased. It also shows the throttle output value on the right top, so if that's still at the same value when working and when not working, while you're turning the cranks, the CA is still doing what it should. If the throttle drops to nothing, it means the CA is no longer telling the controller to do anyhthing.
The randomness is probably equivalent to the part where you get the knocking/etc., and probably means the halls aren't providing the right signals to the controller, so the controller outputs the wrong signals to the motor.
If your grinfineon is like mine, then it has sensorless fallback if you unplug the halls, but if it just gets corrupt hall signals it can drive the motor wrong. If it loses just one hall signal but hte other two are ok, it should be able to still operate in a form of sensored mode, as long as the motor is spinning fast enough though at startups it might be rougher.
If it loses a phase connection but the halls work then the contorller can't tell, so the motor runs rough adn may feel "gutless", and may not start on it's own, might just grind or sit there.
So...the first thing I'd check is the connections between motor and controller, and all of the wiring and cabling especially at the axle exit from the motor, and where it enters the backs of connnectors, etc.
The other thing you can check is the CA's diag screen, one left button push from the main screen. Any letters on the left lower side should stay lowercase. uppercase means that limit is engaging, which means the htrottle output from it to your controller is being modified / decreased / ceased. It also shows the throttle output value on the right top, so if that's still at the same value when working and when not working, while you're turning the cranks, the CA is still doing what it should. If the throttle drops to nothing, it means the CA is no longer telling the controller to do anyhthing.
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