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Understanding Battery ReadoutsUpdated a month ago

These are the standard readouts from the battery management system (BMS)—viewable in the info section on the Bafang display. Here’s what each one actually means in plain terms:

How to access Battery Details on the Bafang C080 display

View Battery Details
  • Battery Software / Hardware Version and Status Information
  • Press (+) and (-) for at least 2 seconds to enter the "Setting" mode
  • Press (+) or (-) to select "Information"
  • Press the "Power button" to enter "Information" mode
  • Press (+) or (-) to select "Battery Info"
  • Press the "Power button" to enter "Battery Info" mode
  • Press (+) or (-) to select "→"
  • Press the "Power button" to confirm your selection
  • Press the "Power button" to scroll through the "Battery Info" screens
  • Press (+) and (-) for at least 2 seconds to return to the main screen
  • Or press (+) or (-) to select "Back", then press the "Power Button" to return to "Battery Info". Then select "Exit" and press the "Power button" to confirm.
  • Note: Battery info is for reference only and cannot be modified

🔧 System Info

  • SW (Software)
    Version of the BMS firmware controlling the battery.
  • HW (Hardware)
    Version or revision of the physical BMS board.

🌡️ Battery Condition

  • Temp (°C)
    Current battery temperature.
    • Normal range when being charged: 32°F ~ 113°F (0°C ~ 45°C)
    • Normal range when being ridden: 4°F ~ 140°F (-20°C ~ 60°C)
    • Too high = risk of damage or shutdown
    • Too low = reduced performance

⚡ Voltage & Current

  • Total Volt (mV)
    Total battery pack voltage in millivolts (mV).
    • Example: Bafang 48V x 10.5 Ah Battery (used on the Sun E350 Trike)
      • Total capacity is 54.6 volts (V) or 54,600 millivolts (mV)
        • Assuming 100% charged battery
  • Current (mA)
    Average current flow.
    • Positive = discharging (using power)
    • Negative (if shown) = charging

🔋 Capacity & Charge

  • Res Cap (Ah) (Remaining Capacity)
    How much charge is left in amp-hours.
  • Full Cap (Ah) (Full Capacity)
    Maximum capacity the battery can currently hold.
    • This decreases over time as the battery ages
  • RelChargeState (%) (Relative State of Charge)
    What most people think of as “battery %.”
    • Based on current usable capacity
  • AbsChargeState (%) (Absolute State of Charge)
    Charge relative to the original factory capacity.
    • Useful for understanding battery wear

🔄 Battery Usage & History

  • CycleTimes
    Number of full charge cycles (0–100% equivalents).
    • 1 cycle = total of 100% used (not necessarily in one session)
  • M.N.T (Max. No-charge Time)
    Longest time the battery has gone without being charged.
  • L.N.T (Last No-charge Time)
    Time since the battery was last charged.

🔋 Cell-Level Info (Very Important)

  • Cell (Qty.)
    Total number of cells in the battery pack.
  • Cell 1–13 (mV)
    Voltage of each individual cell group.
  • Each cell as a capacity of 4.2 volts (V) or 4200 millivolts (mV)
    • Assuming 100% charged healthy cells
    • If a single cell reaches at least 4150 mV, it is considered fully charged

👉 This is critical for diagnosing battery health:

  • All cells should be very close in voltage
  • Typical difference: ≤ 30–50 mV
  • Larger differences = imbalance → possible issue

🧠 Quick Real-World Interpretation

  • Healthy battery:
    • Even cell voltages
    • Full Cap close to original spec
    • Normal temperature range
  • Aging battery:
    • Lower Full Cap
    • AbsChargeState lower than RelChargeState
  • Potential problem:
    • One cell significantly lower than others
    • High temperature
    • Rapid drop in remaining capacity
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