Notes

  • Before connecting the battery to the bike, disable the discharge port using the Overkill Solar BMS app or the Xiaoxiang BMS app.
  • Avoid using the stock ONYX BMS app, as it is outdated and no longer maintained. Instead, opt for the Overkill Solar BMS app or the Xiaoxiang BMS app for better functionality and support.
  • Prolong the charge cycle lifespan by consistently limiting charging to a maximum of 82 volts.

Resrouces

regular

Connecting the charger to the ONYX 41AH battery

To avoid sparking during the connection process, always plug the charger into the wall outlet first, then connect the charger cable to the battery’s XLR circular three-prong connector.

ONYX 41AH Battery Charging Times

5 Amp Charging To 100% (84 Volts)

  • 0% To 100% - 10.6 Hours
  • 50% To 100% - 7.6 Hours

5 Amp Charging To 97% (83.3 Volts)

  • 0% To 100% - 9.2 Hours
  • 50% To 100% - 3.6 Hours

10 Amp Charging To 100% (84 Volts)

  • 0% To 100% - 5.4 Hours
  • 50% To 100% - 3.6 Hours

10 Amp Charging To 97% (83.3 Volts)

  • 0% To 100% - 4.6 Hours
  • 50% To 100% - 1.8 Hours

ONYX 41AH Range

These real-world range averages are based on my experience and input from others. Your actual range may vary—potentially more or less—depending on factors like your location, weather conditions, battery health, riding style, and other variables.

NEW YORK CITY - FLAT

  • ECO Mode / 80 Miles Range
  • Normal Mode / 65 Miles Range
  • Sports Mode / 45 Miles Range

SAN FRANCISCO - HILLS

  • ECO Mode / 70 Miles Range
  • Normal Mode / 55 Miles Range
  • Sports Mode / 35 Miles Range

ONYX 41AH Battery Charge Level

The ONYX RCR display features both a battery charge bar and a voltmeter. For an accurate reading of the battery’s state of charge (SOC), I recommend primarily using the voltmeter. Keep in mind that the ONYX RCR draws 0.6 volts when powered on, and the updated ONYX RCR v1.5 compensates for this.

On the ONYX Motorbikes 41Ah battery page, it specifies the battery’s operational range as 84 volts fully charged to 55 volts depleted, which is accurate, though 60 volts depleted can also be considered valid. Digging into the battery management system (BMS) settings, the “cell full voltage” field lists 4.15 volts per cell, resulting in a total of 83 volts when fully charged. This appears to conflict with the stated “total battery capacity” of 41000mAh, which aligns with 84 volts.

Similarly, the depleted “total cycle capacity” of 32800mAh conflicts with the “cell 20% capacity voltage” field, which is set to 3.300 volts per cell. These apparent discrepancies are due to battery balancing. In practice, there’s no need for concern—the BMS ensures the battery operates optimally, delivering the full 41Ah capacity as intended.

Battery Pack

In personal electric vehicles, the battery pack comprises multiple individual cells, typically ranging from 160 (72V) to 200 (72V) batteries. These cells are almost always Lithium-ion 18650 or 21700 NMC (Lithium Nickel Manganese Cobalt Oxide) batteries. Each cell operates at a fully charged voltage of 4.2V and discharges to a minimum of 3.0V.

Cell Drifting

It is normal for individual cells within a battery pack to drift slightly in voltage, a phenomenon known as “cell drifting,” which reflects an unbalanced state. There is no way to prevent cell drifting, but it is managed by the Battery Management System (BMS). Drifting occurs due to factors such as time, load variations, peak demands, constant use, temperature fluctuations, and regenerative braking.

Cell Delta

The difference in voltage between individual cells is referred to as the “cell delta.” A healthy cell delta typically falls between 0.005V and 0.040V—the lower the delta, the better the pack’s overall balance.

Battery Management System (BMS)

The Battery Management System (BMS), housed within the wrapped battery pack, is responsible for balancing the cells. Its primary function is to equalize the charge voltage of the cells, aiming for minimal variance, with a delta of 0.005V being ideal.

Not all BMS units handle battery balancing the same way. Some require a balance-compatible charger to be connected for a set duration to activate the “balance function.” Others operate independently, continuously balancing the battery without the need for a charger connection.

Modern BMS designs often feature Bluetooth connectivity, allowing real-time monitoring via iOS or Android apps. These systems display individual cell voltages, series voltage levels, and the battery’s overall cell delta value.

Charging Process

To charge your battery correctly:

  • Plug the charger into the wall outlet first.
  • Then connect the charger’s cable to the battery’s XLR (three-prong circular) connector.

This sequence prevents sparking and ensures a safe connection.

High-Temperature Charging

When temperatures rise above 85°F, lithium batteries behave differently during both charging and discharging. Aggressive riding, faster speeds, and intense hill climbing can generate higher internal battery temperatures.

The ONYX 41Ah battery cells are rated for operation up to 140°F, with the BMS cutting off power at 158°F. You can monitor the battery’s temperature using the BMS app.

If temperatures reach 120°F, it’s a good indicator to ease off the throttle. Treating your battery with care on hot days will help maintain its performance and extend its charge cycle lifespan over time.

Battery Safety

After a ride, allow the ONYX RCR 41Ah battery to rest in the shade for about 30 minutes before charging, especially if using a 10-amp fast charger. On days hotter than 90°F, wait at least an hour. Use the Overkill Solar BMS app or Xiaoxiang BMS app to monitor internal temperatures. If the battery is above 105°F, wait until it cools below 95°F before charging, especially at higher currents like 10 amps.

Resting the battery after riding has significant benefits for longevity and performance. It increases the charge cycle count, allows ions and electrons to stabilize, reduces operating temperatures, and minimizes the risk of thermal runaway-something no BMS can entirely prevent after a hard ride on a scorching day.

  • Avoid charging the battery in direct sunlight.
  • Keep the battery away from heat sources like radiators while charging.
  • Refrain from charging immediately after racing, hill climbs, or on days above 90°F.
  • Periodically clean the charger’s XLR pins and the battery’s XLR port using Isopropyl alcohol 70% or connector contact cleaner.
  • Do not charge or store the battery in environments where temperatures drop below 32°F or rise above 120°F.
  • If the display voltmeter fluctuates randomly while the battery is at rest, stop using it immediately. Turn the battery off, move it to a safe outdoor location, and contact ONYX Motors for assistance.

Charging Safety

Overnight charging is safe with the ONYX RCR’s stock 5-amp charger, 10-amp charger, and battery management system (BMS), which include multiple fail-safe mechanisms. As the battery charge level approaches 97% (83 volts), the charger significantly reduces its amperage output and begins trickle charging. This minimizes heat generation and turns off the charger’s cooling fan for the remainder of the process. Once fully charged, the ONYX 41Ah BMS automatically cuts off both the stock 5-amp and the ONYX 10-amp SFX charger.

Best Practices for Battery Longevity:

  • For long-term storage, keep the battery at 74 volts.
  • Between rides, maintain the charge between 78 and 81 volts to extend its charge cycle lifespan.
  • Avoid intentionally keeping or discharging the battery below 64 volts or at 84 volts for extended periods, as this does not improve battery health.
  • It’s fine to leave the battery fully charged at 84 volts for a day or two, but avoid making it a regular practice.

Protective Cap

The ONYX RCR is now equipped with a protective cap for the charging cable, located just outside the right-side porthole. For added protection during winter or rainy conditions, replace this with an XLR rubber cap to shield it from moisture and debris.

Cleaning Connectors

Regularly cleaning the male charger pins and female battery porthole connectors helps minimize electrical resistance, ensuring efficient charging and preventing heat buildup. Follow these steps:

  • Turn off the battery using the BMS app.
  • Remove the cotton from one end of a cotton swab and apply two drops of contact cleaner to the exposed end.
  • Gently insert the bare end into the battery’s female portholes, twisting to clean the contacts.
  • Apply two drops of contact cleaner to the intact cotton end of the swab and use it to clean the male charger pins.

OSE 8 Connector Soldering Instructions

  • Power Down the Battery: Use the app to turn off the ONYX 41Ah battery before beginning any work on the battery connector.
  • Discharge the Bike: Unplug the battery from the ONYX RCR while the bike is powered on to ensure the bike’s connector is cold and safe to handle.
  • Work with Caution: If you’re unfamiliar or uncomfortable replacing the stock SB50 connector with an OSE 8 connector on both the battery and bike, always consult a professional for assistance.

Safety first-never compromise on precautions when handling high-power batteries!

Amperage Update

The ONYX 41Ah BMS has been upgraded from an 80A model to a 100A model. Previously, the discharge overcurrent setting in the BMS app was configured at 90A; it is now set to 110A. This update allows the 41Ah battery to output 20 additional amps, resulting in increased torque and potentially a slight speed boost.

Compatibility Note

  • The stock SB50 connector on the battery is rated for 50A continuous with a 70A peak, which limits the full potential of the upgraded BMS.
  • The revised ONYX RCR 1.5 now includes a 100A fuse, aligning with the new BMS capabilities.

Upgrade Recommendation

While the ONYX RCR will operate fine with the stock SB50 connector, upgrading to an OSE 8 connector is necessary to fully utilize the increased amperage output of the 41Ah battery.

Verify Your BMS Model Using the Xiaoxiang BMS iOS App

  • Connect to Your Battery: Open the Xiaoxiang BMS app and pair it with your battery.
  • Access BMS Settings: Tap “BMS Settings” at the bottom of the screen.
  • Read the BMS Info: Select “BMS Read” and scroll to find the line labeled “BMS Name.”
  • Check the Model Number:
  • If the model number ends in “80A,” you have the 80A version.
  • If it ends in “100A,” you have the 100A version.

Charge Cycles

  • Extend Battery Life: To more than double the charge cycles, unplug the stock 5A or SFX 10A charger when the battery reaches 80 volts.
  • Before Riding: Charge to 82V or 84V depending on your expected range for the ride.
  • Weekly Maintenance: Keep the battery above 74 volts when not in use.

Performance

  • 5A Charger: Charging with the stock ONYX 5A charger maximizes long-term battery runtime.
  • 10A Charger: Using the ONYX SFX 10A charger enhances acceleration performance but may shorten the battery’s lifespan over time.

Voltage Sag

  • Definition: Sag refers to the voltage drop caused by throttle demand.

Expected Sag

  • On cold days: 3 volts under throttle in sports mode.
  • On hot days: 4 volts under throttle in sports mode.

Minimizing Sag

  • Eco and Normal modes reduce sag significantly.
  • Throttle usage directly impacts sag levels.

Cut-Off

  • Automatic Recovery: If the battery cuts off due to low voltage or sag, wait 10 seconds for the BMS to automatically reengage the battery.
  • Advice: Always carry your key fob to avoid being stranded.

Resting Voltage

  • Ideal Range: Let the battery rest overnight or for extended periods between 68 volts and 79 volts.
  • Avoid: Resting above 82 volts or below 62 volts, as these levels can negatively impact battery lifespan.

Charging amperage

Low Amperage (1–3 amps)
  • Healthier for the battery.
  • Slightly increases range but may reduce peak power output.

High Amperage (7–10 amps)

  • Allows for higher peak output levels.
  • Less beneficial for battery longevity.

BMS Bypass

Advanced Use Only

  • Riders with technical knowledge can bypass the BMS to achieve higher discharge levels.
  • Risks: Disabling cell group cut-off and short circuit protection can lead to battery damage or destruction.
  • Recommendation: With proper BMS tuning (e.g., Sicko mode), bypassing the BMS offers minimal benefits and sacrifices critical safety protections.

Charge Cycles

Voltage & Longevity

  • Every 0.10 volts below 4.20 volts doubles the battery’s charge cycles.
  • Charging an ONYX 23Ah battery to 82 volts instead of 84 volts can double its charge cycle life from 800 to 1600 cycles, while only sacrificing about 2 miles of range.

Definition of Charge Cycles

  • The number of times a battery can be recharged before degrading to 80% of its capacity, which reduces peak power output.

Charging Habits

  • I charge my batteries to 79 volts 90% of the time, providing more range than needed while achieving a 5x increase in charge cycle life and maintaining strong peak performance.
  • For the remaining 10% of charges to 84 volts, I still benefit from approximately a 4x increase in charge cycle life.

Takeaway

  • It’s never too late to adopt better charging habits. By slightly reducing charge voltage and avoiding extreme resting voltages, you can significantly extend the lifespan of your battery without compromising performance.

Charge Level Cycle Increase

  • 83 volts (97.5%): Increases charge cycles by 1.5x.
  • 82 volts (92.5%): Doubles charge cycles to 2x.
  • 81 volts (87.5%): Triples charge cycles to 3x.
  • 80 volts (85%): Quadruples charge cycles to 4x.

Tracking your actual riding mileage often reveals that fully charging the battery isn’t always necessary. By experimenting with charging to 82 volts, you’ll likely find it provides more than enough range while also doubling the battery’s charge cycle life.

Charge Cycle Advice

  • Avoid full charges out of range anxiety; instead, charge to 80% or 90% for better battery longevity.
  • Understand your actual range and voltage to manage range anxiety effectively.
  • Invest in a dedicated home charger that can be programmed to cut off at 80% or 90% charge levels.