Need Help Hub Motor


New member
Local time
3:11 PM
Mar 9, 2021
When I connect my battery to the Controller it trips the Battery BMS.
Here is what I have:
Hallowmotor High Power Ebike 72V 100A 3000W-5000W Intelligent Programmable Control 19" Motorcycle Rim Rear Wheel Conversion Kits
19" Motorcycle Wheel Size is the same as 24x3.0'' bicycle wheel

72V Universal 3000W-5000W 19" Motorcycle Rim Rear Hub Motor Wheel
Risunmotor 48V/60V/72V Universal 100A 3000W-5000W Sine Wave Intelligent Programmable Controller
Full Color TFT-750C or UKC-1 Color Display (We will choose randomly for you)
Disc Brake cut off power
Pedelec Assistant Sensor/8 Magnetic PAS Drive

Voltage: 72V
Capacity: 30Ah
Dimensions: 245*175*165mm
Charging Current: <=10 A
Maximum Continuous Discharging Current: 50 A
Maximum Discharging Current: 100 A
Discharging Cut off Voltage: 50V
Chemical Composition: Lithium ion/li-ion
Lifecycle : >= 500times
BMS : Built in battery

This is installed on a custom built trike ( Like a Morgan) with drive wheel in rear. So I am Not using PAS.

The battery is connected through Anderson plug to separate 1/4" terminals, the + gpes through a 100A cut off switch between the Anderson connector and the Terminal.
From terminals i Have 10Ga Copper wire to to controller and 12Ga copper wire to 72V-12V converter.
Fully charged battery measure 82V
With the controller disconnected I have 12V power to my lighting (LED) which works fine.
When I connect the controller it trips the battery BMS and voltage at controller reads 1.8V
I have disconnected the motor and all other connections from the controller so there is no load and it still trips the BMS.

Contacted Hallomotor and they claimed that the controller is 100A and requires a 100A Continuous battery. So they swapped out the controller for an 80A 200W- 4000W Controller.Still does the same thing.

I have contacted the battery supplier to find out what the BMS is rated for. I had assumed that since the battery is rated for 100A Max that that is the BMS Limiting. I have not heard back from the Battery supplier.
What I dont understand is why the controller would trip the BMS with no load. Not getting much help from Hallomotor and it difficult communicating with them being 13 hours ahead of me.

Could it be the BMS is rated much lower than 80A and would the controller cause it to trip with no load?
I have full voltage at the terminals from the battery before I connect to the Controller. The battery powers my 12V converter just fine when Controller is disconnected.
Any suggestions or recommendation are appreciated.
It seems to me that the battery BMS should only trip as a result of excessive amp load from the battery? I don’t see how the controller could trip the BMS unless it was pulling a load higher than the battery BMS could support. Of course since you weren’t using any throttle that amp load would be nothing initially. since you have already change the controller for a different one, I would think that the battery BMS was defective. I wish I had more experience and could help you more, but all of my projects have lead acid batteries because of the initial cost of lithium ion when I built my bikes. Now I am converting and probably will be experiencing the same kind of issues. Lee
I've had to replace the bms on my 48v 20amp hour cheap Ebay battery. I found one on Ebay for $12. I don't think that battery could ever run a 5000 watt hub though. Is it an 18650 pack?