FarDriver Regenerative Braking and Full-Battery Cutouts for ONYX RCR

This article explains the recorded FarDriver regen system and its interaction with the ONYX battery and brake input.

Reference Applicability

The explanations and tables below are the blog’s recorded FarDriver parameter reference, not a universal tune. The complete settings snapshot remains in Jaws Mode Settings. The parameter reference and settings snapshot have unresolved differences: 500 RPM is 100% versus 98%, 2250 RPM is 80% versus 58%, and LowSpeedPhaseRatio is 65% versus 60%. Their revision/hardware basis is not recorded. Do not combine the records or overwrite motor-specific learned values.

Firmware labels, scaling, motor pole pairs, installed wiring, and battery limits determine applicability. Interpret descriptions of riding feel as the source’s explanation, not proof of an outcome on every build.

Battery and Braking Limits Come First

The 20A/40A values and the source’s 20-40A guidance below are recorded examples, not a safe range for every battery. Charge acceptance can change with state of charge, temperature, chemistry, and BMS behavior. Descriptions such as “Safe” in the source table are comparative source labels, not certification of traction or braking safety.

A cutout during braking near full charge requires diagnosis of battery voltage, BMS behavior, installed brake logic, and regen demand. Do not raise OverVolProtect to conceal it. The 91.1V/89.6V reference pair does not establish suitable protection for an 84V-full battery or any other pack. Keep protection within verified component/battery limits; reduce or disable regen as the applicable equipment requires and use functioning mechanical brakes. Stop riding tests after an unexpected cutout.

The source’s suggestions to “adjust voltage protection” are retained as historical tuning discussion, not a general remedy. FarDriver’s control-parameter instructions connect electronic braking to brake-signal detection, the Follow selection, and return-current limits. Confirm those labels on the installed firmware.

Energy Feedback (EABS)

Core behavior:

• Energy Feedback defines baseline regenerative braking force when throttle is released or braking is applied
• It controls how much current is sent back into the battery during deceleration
• Acts as the primary “feel” setting for regen before fine control via current limits

Interaction layer:

• Directly interacts with MaxBackCurr, which defines the maximum regen current
• Works with regen RPM tables to shape braking behavior across speed ranges
• Influences battery voltage rise during regen, interacting with OverVolProtect

Real-world behavior:

• Low -> minimal braking, bike coasts freely
• Medium -> predictable deceleration, suitable for most street riding
• High -> strong braking effect, reduces need for mechanical braking but increases instability risk

Limits and failure modes:

• Increasing regen does not improve performance, only braking behavior
• High regen at high battery state can trigger over-voltage cutouts
• Excessive regen can cause rear wheel slip, especially on QS motors with high torque

Tuning Guidance (ONYX-Specific)

• Use Medium as the baseline for ONYX street setups
• Increase to High only if additional braking force is required and traction is sufficient
• Always verify stability under braking after increasing regen strength
• If experiencing cutouts during braking, reduce regen or adjust OverVolProtect before changing other parameters
• Do not rely solely on regen for braking - ensure mechanical braking remains primary for safety

ENERGY REGENERATE

Core behavior:

• Energy Regenerate defines how kinetic energy is converted back into battery energy during deceleration
• It controls negative current (regen current), acting as inverse torque
• Regen behaves as a braking system driven by electrical load, not mechanical friction

Core relationship:

Regen Torque ∝ BackCurrent

Interaction layer:

• MaxBackCurr defines the ceiling of braking force
• StopBackCurr defines baseline braking at low speed
• Energy Feedback (Simple Mode) sets overall regen feel
• OverVolProtect interacts with regen when battery voltage rises
• Ratio In Speed indirectly affects regen stability at higher RPM

Real-world behavior:

• Flat regen table (-25%) -> consistent braking across all speeds

• Low regen -> coasting feel, minimal braking

• Moderate regen (this setup) -> predictable, smooth deceleration

• High regen -> aggressive braking, reduced need for mechanical brakes

• Riders experience:

  • Stable regen -> smooth deceleration without jerks
  • High regen -> strong engine-braking feel
  • Poor tuning -> grabby or inconsistent braking

Limits and failure modes:

• Excessive regen -> rear wheel slip (especially QS motors)
• High regen + full battery -> over-voltage cutout
• Too low regen -> ineffective braking, over-reliance on mechanical brakes
• Uneven regen table -> inconsistent braking feel across speeds

Tuning Guidance (ONYX-Specific)

• Use ~20-40A range for safe, usable regen on QS motors
• Keep regen table flat for predictable behavior unless advanced tuning is required
• Avoid high regen at high RPM without testing stability
• Monitor for cutouts - reduce regen or adjust voltage protection if triggered
• Regen should assist braking, not replace mechanical brakes

Input Logic and Protection Reference

These rows are selected from the mixed FUNCTIONS, PRODUCT, and PROTECT tables. They retain the source values; they are not recommended defaults.

Related Articles

• Mechanical brake diagnosis
• Next step: Validate braking and controller behavior