Help Docs – Lift Battery Codes

Many people have wondered what the lights on their batteries mean. It seems like the battery is always flashing some combo of lights, trying to talk to us. Well, here is how to decode it! This specific set of instructions is for Firmware Version V0.9.40, but is mostly accurate for current firmware versions.

Huge shout-out to Matze over on the forums for putting this together.

Lights should be read with the handle facing you.

The LED indications depend on what state the battery is in, as described below

1.1. Initial Reset

1. LED1 – LED2 Blue for 3 Seconds: BMS Board Revision B (Old)
2. LED1 – LED3 Blue for 3 Seconds: BMS Board Revision C (Latest)
3. LED8 0.5 seconds after Blue Indication:
   a. Green: Battery Voltage is Greater than Shutdown Voltage (47V)
   b. Yellow: Battery Voltage is Less than shutdown Voltage (47V)
   c. White: BMS Board Revision B (Old)

1.2. Sleep

1. LED1 – LED8 Green 0.5 Second Blink Every 5 Seconds: Proportional to Battery State of Charge (SOC)

1.3. Charging Startup

1. Single Green LED Indicator Scrolling between LED1 and LED8: Charging Startup Procedure

1.4. Charging

1. LED1 – LED8 Green: Proportional Indication of Battery State of Charge (SOC). Modified by the following:
   a. If One LED is Blinking Green at 2 Hz: More than 2 Amps of Charging Current is Flowing into Pack.
   b. If One LED is Blinking Yellow at 2 Hz: Cell Voltage Imbalance of >100mV is leading to reduced charge rate. Cell Balancing is active.
   c. If LED1 is Blinking Yellow at 1 Hz: Battery Charge Current is Limited due to High Temperature.
   d. If LED1 is Blinking Purple at 1 Hz: Battery Charge Current is Limited due to Low Temperature.

1.5. Charging Complete

1. LED1 – LED8 Blinking Green at 0.5 Hz: Battery Pack is Fully Charged

1.6. Active States

1. LED1 Blue: Battery Pack is in Startup (lasts 2 seconds)
2. LED1 – LED2 Blue: Battery Pack is in Idle State
3. LED1 – LED3 Blue: Battery Pack is in Precharge State (lasts a few seconds)
4. LED1 – LED4 Blue: Battery Pack is in Active State and ready for discharge (contactor closed)

1.7. Battery Fault

1. LED8 Yellow: Battery Fault is Active. Other LEDs indicate which fault conditions are present.
2. LED1
   a. Yellow: Cell Over-Voltage Fault
   b. Purple: Cell Under-Voltage Fault
   c. Blue: Failed Thermistors Fault
3. LED2
   a. Yellow: Pack Over-Voltage Fault
   b. Purple: Pack Under-Voltage Fault
   c. Blue: Pack Voltage Sense Fault
4. LED3
   a. Yellow: Cell Over-Temperature Fault
   b. Purple: Cell Under-Temperature Fault
5. LED4
   a. Yellow: Charge Current Envelope Exceeded Fault
   b. Purple: Discharge Current Envelope Exceeded Fault
6. LED5
   a. Yellow: Power Connector Over-temperature Fault
   b. Purple: Cell Voltage Reading Mismatch Fault (Indicates Internal Voltage Calibration is Off)
7. LED6
   a. Yellow: Pre-charge Timeout Fault
   b. Purple: 12V Output Fault (Indicates possible short-circuit on 12V output)
8. LED7
   a. Yellow: Charger Voltage Mismatch Fault
   b. Purple: Charger Current Mismatch Fault

1.8. Severe Battery Fault

1. LED8 Red: Severe Battery Fault is Active. Battery operation is prevented for safety reasons. Other LEDs indicate which fault conditions are present.
2. LED1
   a. Red: Severe Overtemperature Fault (battery has measured extreme temperatures previously)
   b. Blue: Contactor Failed Fault (Contactor has Failed Open)
3. LED2
   a. Red: Severe Cell Under-Voltage Fault (It is not safe to recharge battery)
   b. Blue: Current Sensor Fault (Current Sensor is no longer functioning properly)
4. LED3
   a. Red: Severe Cell Group Capacity Loss Fault (Too many cells have been disconnected or failed to safely operate)
5. LED4
   a. Red: Open Cell Group Fault (An entire cell group is disconnected from the voltage stack)
6. LED5
   a. Red: Open Cell Voltage Sense Connection (BMS cannot reliably measure one or more cell group voltages)

1.9. Firmware Update
2. LED1 – LED8 Blue: Indicates battery is in bootloader mode, awaiting new firmware.