openinverter forum

Hello,

I am using a ZombieVerter VCU with a Nissan Leaf drivetrain (PDM, EM57 motor, inverter) coupled to a 6-gear manual gearbox. I am kindly requesting guidance on how to set regenerative braking correctly.

The car was making a noise whenever I pressed or lifted my foot off the throttle while driving. I discovered that the issue was related to regenerative braking, so I changed Regenendrpm from the default 100 RPM to 1000 RPM.

This completely stopped the noise when driving at speeds below 1000 RPM. However, when driving at higher speeds and lifting my foot off the throttle, the noise is still present.

I have shared my current parameters for reference.
Thank you in advance for your assistance.

I have no scientific evidence but it seems regen is hard on the transmission that is only supposed to transfer torque in the "drive" direction. My transmission was screaming heavily in Norway when descending long steep hills. Soon after it broke alltogether though.

A manual transmission coupled to an ice engine only needs to handle Internal Combustion Engine pumping losses + drag in deceleration.
An electric motor can make way more deceleration / regen energy than an ice.
The ring and pinion gets pulled on opposite in regen / decel and typically has a much smaller bearing to work with.
I'd guess it's a case by case basis on what different manual transmission designs can handle for regen in ev swaps.

maiks wrote: ↑Sat Dec 27, 2025 6:01 pm
The car was making a noise whenever I pressed or lifted my foot off the throttle while driving. I discovered that the issue was related to regenerative braking, so I changed Regenendrpm from the default 100 RPM to 1000 RPM.

This completely stopped the noise when driving at speeds below 1000 RPM. However, when driving at higher speeds and lifting my foot off the throttle, the noise is still present.

I have shared my current parameters for reference.
Thank you in advance for your assistance.

Regenendrpm is well at what rpm do you want to stop regen. So yes at high speeds (when the motor is spinning over 1000rpm) you will have regen still.

try adjusting regenmax and regenramp.

Bratitude wrote: ↑Sat Dec 27, 2025 11:17 pm Regenendrpm is well at what rpm do you want to stop regen. So yes at high speeds (when the motor is spinning over 1000rpm) you will have regen still.

try adjusting regenmax and regenramp.

Thank you . The noise is gone
Have changed the following parameters as follows
Regendrpm to 500
Regenmax to -5
RegenBrake to -5
Regenramp to 0.15

Do you even have the brake input wired up?

If not, adjusting regenbrake will do nothing.

Bratitude wrote: ↑Mon Dec 29, 2025 1:53 pm Do you even have the brake input wired up?

If not, adjusting regenbrake will do nothing.

Yes l have the brake input from brake pedal to the vcu