72v Fardriver shuts down under throttle

[Peezy]

Setup:

-Fardriver 72450
-72v 25ah battery
max constant discharge current: 50a
peaking discharge current 100a 5s
-kunray 3000w motor



When I have the rear wheel off the ground and pull the throttle 100% it’s fine. If I sit on the bike and try and move it, it’ll move for 2-3 feet and then shut down. My old Kunray controller setup worked fine, so I have a feeling I have something wrong in my settings. I’m sure it’s a simple fix but this is all relatively new to me!

I have tried to change my max line current to 50 and max phase current to 100 and had the same results.

 

[amberwolf]

By shut down do you mean it powers off, or just stops operating the motor?

If it actually powers off, then the most likely issue is the battery being unable to supply the demanded current and the BMS shutting off it's output.

If it doesn't actually power off, it can still be a battery issue where voltage drops below the LVC of the controller because the load is too high for the battery's condition.


"line" current is usually battery current, so if your battery is only capable of 100A peak, having a "boost" line current of twice that could be the problem.

If the battery is only capable of 50A continuous, then having a regular line current of 70A is probably also a problem.

 

[dominik h]

If you loose Bluetooth connection to the controller then the BMS cuts off.

I would set line and boost current to 40A , retry and see what happens.

I would also set temp sensor to "Cacu" if the motor does not have a sensor the controller will calculate the temperature in the motor. The rated power is the value with which the controller estimates the thermal capabilities of the motor.

 

[TommyCat]

3 pole pairs… is that accurate?

 

[dominik h]

The fardriver needs the pole pairs only for rpm calculation. I can set what i want as Pole pairs, nothing changes during driving only the rpm on the screen.

 

[Peezy]

It looks like I had a loose wire in my hall sensor, so that seems to have fixed it! Now I just need to see what else I can do to make this a super fun dirt ripper!