Mower Battery Issues: Fast Charging, Slow Charging or Short Runtime

Overview

If your robotic mower shows any of the following issues, a BMS calibration may help restore normal battery performance:

• Abnormal fast charging: The battery charges too quickly, for example from 20% to 100% in about 30 minutes or an unusually short time
• Abnormal slow charging / no charging: Charging takes more than 5 hours, or the device may be described as not charging or unable to charge
• Reduced runtime: The mower runs for less than 1 hour before entering low battery mode, or
• The mower shuts down during the return-to-charge process when battery is still around 20%

If you experience any of the above symptoms, please follow the BMS calibration steps below.

BMS Calibration Procedure (Important)

This process requires 5 full charge and discharge cycles.

Before you start

• Use the original charger only
• Ensure environment:
  • 15°C–30°C (59°F–86°F)
  • Dry, clean, no fire hazards or strong electromagnetic interference
• Check battery condition:
  • No swelling, leakage, or unusual odor
  • Mower operates normally

Step-by-step process (Repeat 5 cycles)

1. Full Discharge

To ensure a more complete and faster discharge process, please follow the steps below:

1. Tap Start to begin a temporary mowing task and let the mower leave the charging station to start mowing. This helps accelerate battery consumption.
   • Monitor the battery level during operation
   • If the mower completes one mowing cycle and the battery is still above 20%, start another mowing task

   • Repeat this process until the battery drops below 20%

      

2. When the battery is below 20%, the mower will normally initiate automatic return-to-charge. Before it enters the charging dock, press the Stop button to prevent it from returning to charge
   • Then tap Manual Mode, and in the top-right corner enable the mowing motor
   • This allows the mower to continue consuming power more quickly until it powers off automatically due to battery depletion

Once the mower powers off automatically, do not charge it immediately. Let the device rest for 30–60 minutes

2. Full Charge

1. Press and hold the OK button to clear any abnormal status on the device.
2. Place the mower back into the charging dock and use the original charger only to charge it.
3. When the indicator light turns green, the battery is usually fully charged. However:
   • Continue charging for an additional 1–2 hours
   • Do not disconnect the charger immediately after it turns green
4. After 1–2 hours of additional charging, disconnect the power supply.
5. Let the mower rest for 30–60 minutes before starting the next full discharge cycle.

3. Record each cycle

Record:

• Discharge time
• Charging time

Important safety notes

• Do not manually power off during discharge
• Do not use non-original chargers
• Stop immediately if battery swells, overheats, or smells unusual
• Do not skip resting time

How to confirm success

• Last 2–3 cycles show stable charge/discharge times
• No shutdowns or battery errors
• Battery performance becomes stable

If the issue persists

If the problem is not resolved after calibration, please share the recorded results with us. Our support team will further assist you with after-sales solutions.