naz.ride
New Member
Hi all E-Bike gurus!
I kindly request assistance for a DIY E-Bike that is new out of the box but is yet to function.
First of all I'm helping someone else get their bike going and while I have experience with electronics I can't seem to pick apart the the symptoms to understand the issue.
The bike as far as I can tell is generic though 'Bluedot' returns images of similar bikes. Looks similar to a 'stealth bomber' (im in Australia).
It has a SW900 LCD and the motor controller (from research) appears to be a 72V 150A Sabvoton (I have photos and also pictures of the plugs and associated wire function/colours if required).
I will try to explain what I have tested so far, hopefully someone reading will identify the issue or point me in the right direction for further testing.
So experiencing no power/display on bike. My first question is whether or not battery/charger voltage should drop to almost nil when the motor controller is connected.
The 72v battery measures approx 65v (seems nominal just uncharged) and the charger outputs 82v (approx.) when disconnected.
However as soon as either is plugged into the motor controller the output voltage drops to less then a few volts (literally 1 or 2 volts) which seems very odd to me, almost like a short.
No heat or anything else abnormal and same results when all or none of the other motor controller wires are connected to rest of bike.
He has two motor controllers and they both operate in the same manner, voltage drop when connected to either power source. Is this normal?
At this point I am thinking the battery/charger to be okay as they both output correct voltages (though subject to load testing).
Im also assuming the rest of the bike components/switches are okay as they are brand new and having these plugged in or unplugged has no effect on the motor controller voltage.
I did test continuty through the key switch to ensure it wasn't something that simple but unfortunately for my issue it worked fine.
Yet to test charging of battery without motor controller connected to help rule out charger or battery/bms. Upon sucessful battery charging would it be reasonable to assume it is the motor controller?
The controller also comes with software though I expected to get no connection without power to the bike, is it worth trying to communicate with the motor controller via laptop?
As I am an engineer/problem solver by profession I also seek to identify the cause of the issue if it is indeed a bad motor controller.
One possibility I observed was that one plug (6 pin motor hall sensor) out of the motor controller could actually clip into two different plugs on the bike frame (both leading to the back wheel).
This plug has 6 pins and on observation one pin had blackening on the inside of the plug. My assumption is that an incorrect connection was made, perhaps twice on two different controllers?
Regardless they are colour coded so shouldn't be an issue when connecting them in the future.
So is battery and charger voltage supposed to drop when connected to the motor controller? And is there anything that would stop the bike from powering on such as a hidden dead man switch?
Thanks for sharing any experience you have had or any potentially helpful input!
Best regards,
Nathan
I kindly request assistance for a DIY E-Bike that is new out of the box but is yet to function.
First of all I'm helping someone else get their bike going and while I have experience with electronics I can't seem to pick apart the the symptoms to understand the issue.
The bike as far as I can tell is generic though 'Bluedot' returns images of similar bikes. Looks similar to a 'stealth bomber' (im in Australia).
It has a SW900 LCD and the motor controller (from research) appears to be a 72V 150A Sabvoton (I have photos and also pictures of the plugs and associated wire function/colours if required).
I will try to explain what I have tested so far, hopefully someone reading will identify the issue or point me in the right direction for further testing.
So experiencing no power/display on bike. My first question is whether or not battery/charger voltage should drop to almost nil when the motor controller is connected.
The 72v battery measures approx 65v (seems nominal just uncharged) and the charger outputs 82v (approx.) when disconnected.
However as soon as either is plugged into the motor controller the output voltage drops to less then a few volts (literally 1 or 2 volts) which seems very odd to me, almost like a short.
No heat or anything else abnormal and same results when all or none of the other motor controller wires are connected to rest of bike.
He has two motor controllers and they both operate in the same manner, voltage drop when connected to either power source. Is this normal?
At this point I am thinking the battery/charger to be okay as they both output correct voltages (though subject to load testing).
Im also assuming the rest of the bike components/switches are okay as they are brand new and having these plugged in or unplugged has no effect on the motor controller voltage.
I did test continuty through the key switch to ensure it wasn't something that simple but unfortunately for my issue it worked fine.
Yet to test charging of battery without motor controller connected to help rule out charger or battery/bms. Upon sucessful battery charging would it be reasonable to assume it is the motor controller?
The controller also comes with software though I expected to get no connection without power to the bike, is it worth trying to communicate with the motor controller via laptop?
As I am an engineer/problem solver by profession I also seek to identify the cause of the issue if it is indeed a bad motor controller.
One possibility I observed was that one plug (6 pin motor hall sensor) out of the motor controller could actually clip into two different plugs on the bike frame (both leading to the back wheel).
This plug has 6 pins and on observation one pin had blackening on the inside of the plug. My assumption is that an incorrect connection was made, perhaps twice on two different controllers?
Regardless they are colour coded so shouldn't be an issue when connecting them in the future.
So is battery and charger voltage supposed to drop when connected to the motor controller? And is there anything that would stop the bike from powering on such as a hidden dead man switch?
Thanks for sharing any experience you have had or any potentially helpful input!
Best regards,
Nathan
