Regen braking fried my controller

[Volt_Ampere]

That's overkill. If you look at schematics, you can find the proper diode. It's probably a 10 amp diode. I don't know proper specs for it offhand. You might want to reach out to one of the vendors here.

[davros]

Nice diodes, I have used that series before. For most applications ( probably not this one) they need to be "heatsunk"

[Volt_Ampere]

Alltrax schematic shows a 6 amp 660Volt "REGEN" diode across the big terminals for Club Car.

[nejccesar]

Originally Posted by Volt_Ampere

If over voltage protection prevents regen, then that might work but if the BMS shuts down while you are driving, the only thing that will protect the controller is a flyback diode on the solenoid big terminals! This needs to be a beefy diode too!

Well If i place the diode on the solenoid, the current generated by the motor will go through the controller first. Should I not place the diode on the A1 and A2 connections on the motor to protect the controller by the regenerative braking if the BMS shuts down?

[davros]

Originally Posted by nejccesar

Well If i place the diode on the solenoid, the current generated by the motor will go through the controller first. Should I not place the diode on the A1 and A2 connections on the motor to protect the controller by the regenerative braking if the BMS shuts down?

I'm mentally struggling with this too, A diode can deal with reverse volt spike but we have an overvoltage in the "normal" direction by my thinking. Big TVS/MOV/Transorb maybe?

[Volt_Ampere]

No. The diode goes on the solenoid. When the solenoid opens under load, the voltage on the controller side can spike way up. The diode gives the current a path so it doesn't generate a large inductive voltage spike.
I have never seen a diode on the motor armature for any cart schematic that I have looked at.

My Yamaha G29's do not have this diode because it's not normal for the solenoid to open when the cart is running. On some carts, the key switch goes to the solenoid so it drops out if you turn the key off while driving. The Yamaha cart doesn't work that way. The key switch goes to the controller and the controller won't open the solenoid.

I just realized that the diode across the solenoid won't help if the BMS shuts down on a Lithium battery. For that, there might need to be a diode across the battery terminals. Don't know if any BMS's have a diode there.

[TheCartBoy]

VA is describing the flyback or suppression diode on the main contactor, this is used for normal cart operation when the contactor is switched off.

For a BMS shutdown and subsequent system overvoltage due to motor regen, you would need some type of zener diode across B+/B-. The zener diode voltage rating would need to be higher than the BMS shutdown voltage but less than what the controller can handle. The zener will work to clamp the voltage to it's rated value.

[nejccesar]

Scrolling through the manuals of 1266 controller, I have found a setting for overvoltage protection. If I understand correctly this would save all my problems and I would not need any diode?
I should set this to 56V as the full battery is 58.4V, and the regen would not activate on a fully charged battery?
See the attached image.
Manual for Curtis 1266A controller: https://plumquick.com/wp-content/upl...66A-Manual.pdf

[TheCartBoy]

Originally Posted by nejccesar

Scrolling through the manuals of 1266 controller, I have found a setting for overvoltage protection. If I understand correctly this would save all my problems and I would not need any diode?
I should set this to 56V as the full battery is 58.4V, and the regen would not activate on a fully charged battery?
See the attached image.
Manual for Curtis 1266A controller: https://plumquick.com/wp-content/upl...66A-Manual.pdf

What is the floating voltage (charger disconnected for a while) once fully charged? I'd set the threshold a bit below that.

[InvalidUsername]

Something you can do to burn off some amps before you descend your hill when you've just charged to 100% is stop the cart at the top of the hill, wait until the solenoid clicks and then release the foot pedal and coast. If you feel resistance trying to slow the cart that's not regen current; it's field or plug current that's coming from the battery pack, not going into it, so there's won't be over-voltage that makes the BMS flip out and shut everything down, which spikes the voltage and destroys your controller. Regen only works when the solenoid is on. If you get a shunt meter like Junctek that shows both positive (discharging) and negative (charging) current you'll see what I'm talking about