I just put 2x 1,000w hub motors on my bike, need assistance!

[Dragonsandfaeries26]

I purchased the AW International 1,000 watt front and rear hub motor kits for my bike with a large home made li-ion battery. At first I was riding around on just the rear powered hub motor to test how long my battery will last with just 1 motor(the power and take-off speed is very poor for this size wattage hub motor) Then I installed the front hub motor and didn't know if I needed to install both controllers to the display, which I just did without thinking, I spliced the wires and connected both to the single display (the e-bike won't function unless the display is turned on) then I hooked up just the white wire on the throttle from the second controller as shown in many youtube videos. So at first all the sudden I had tons of power and take-off, way way more then on 1 rear 1,000w hub motor, I got about 200 feet up the road and the power just stopped, but the display was still on. I turned off and on the display and still nothing, throttle did nothing. Did I stupidly hook up both controllers to the single display and fry something? I am going to disconnect the second controller from the display and hope it will work again and with all that extra power, if it doesn't work and I actually ruined something, I'm going to kick myself in the butt! This has been a big project for me and I haven't had much time to spare to complete it. Does anyone know my error and if it broke something, is it the controllers? I'll find out tomorrow if it works after disconnecting the other controller from the display.

 

[spinningmagnets]

It's possible the BMS shut down the battery.

The nominal rating for the hub motors might be 1,000W each, but...they can draw much more under load. If the two motors drew over 3,000W from the battery...at 48V that's over 60A.

That bring said, It's hard to say, it could be any one of several things.

 

[amberwolf]

Displays aren't normally designed to talk and listen to more than one controller, and vice-versa, *and* they aren't designed to provide "keyswitch/lock/ignition" power to more than one (that last is not normally a problem, but it can be because sometimes these things fail even with only one controller attached!).

If the little transistor inside the display that does the turning-on of the system overheated from powering two controllers, it can fail and then the display will still turn on but the controller's won't.

If you have two kits, then you should have two displays. Connect the "spare" display to just *one* controller and see if ti turns on and works now. If it does, the first display's transistor failed from overload. If it doesn't, try the spare on the other controller. If that also doesn't work then it's not the transistor, but something in both controllers.

If it does work on both contorllers separately, then to use the single display with two controllers you'd need to do something else to turn on the controllers. You can either bypass the display's switching abilty by using an actual switch between battery voltage and hte controller's KSI wires, and manually turn the controllers on/off separately from the display, or use a relay powered by the display to do it from the display.



Secondarily, that doesn't prevent turn on but will prevent correct info from being displayed and *might* keep the right assist level or other settigns from being set (if the display's TX line can't drive two RX lines at once), is that the display is only meant to talk to one controller. Two at once means the data from each controller is going into the same line at the same time (like two people talking at the same time to you it's hard to understand). The display can't understand it, so information may not correctly display on screen (speed, power, etc) and it may not work as expected, it might even send wrong data back to the controllers that can affect their operation depending on system design.

If you must use only one display with two controllers then only connect the TX line from one controller to the display's RX line (the TX line from the display can still be connnected to both controllers' RX lines).