DJI Issues Firmware Updates For TB50 And TB55 Batteries
Updates Address Small Number Of Batteries Reporting Incorrect Power Levels
DJI would like to clarify uncertainties regarding new firmware updates that are now available for users of TB50 and TB55 batteries to enhance the battery management system and optimize power supply during flight. DJI implemented this measure following reports that a small number of TB50 and TB55 batteries have shown incorrect power levels that have led to loss of power mid-flight.
The firmware updates address a rare issue involving the battery state of charge (SOC) calculation algorithm. They add measures in the flight controller to help bolster flight safety and product reliability which are DJI’s top priorities. M200 series drone users are strongly advised to update their drone and batteries to the latest firmware. From 23 November 2018, this safety-related update is mandatory for pilots using DJI GO 4 to operate their M200 series drone as they will experience a flight lock until the update is complete. We ask that pilots allow extra time before their next flight to perform this update to minimize disruption to their operations.
For TB55 batteries used with the M200 series drone, the firmware update will impose these new battery safeguards:
Battery temperature detection before take-off
The battery temperature must be 15°C (59°F) or higher before the aircraft can take off. This is because a battery with low temperature has a higher internal resistance, which causes lower voltage than in warmer conditions. A battery with low voltage will provide a lower level of power to the drone, and hence impose higher risk of a power loss.
SOC (state of charge) detection before take-off
The voltage of the battery will be used to verify the SOC value by the DJI algorithm in the new firmware. This SOC value will be compared to the one calculated by the battery SOC calculation algorithm to determine if there is a “false high” SOC reading. If there is a “false high” SOC reading, then the aircraft will not be able to take off.
Return-to-Home (RTH) or Automatic Landing
When the DJI algorithm detects a difference in SOC levels (this calculation runs within the battery and is therefore not visible to users through the screen) between the algorithm and the actual level that is greater than 5%, RTH (return-to-home) will be activated at a detected battery level of 30% and automatic landing (AL) activated at 10% (based on the DJI algorithm). If the difference is less than 5% then no action will be activated.
For TB50 batteries used with the M200 series drone, the firmware update will impose this new battery safeguard:
Battery temperature detection before take-off
The battery temperature must be 15°C (59°F) or higher before the aircraft can take off. This is because a battery with low temperature has a higher internal resistance, which causes lower voltage than in warmer conditions. A battery with low voltage will provide a lower level of power to the drone, and hence impose higher risk of a power loss.
Please note:
For the time being, pilots who are using drones of both the DJI M200 series and the DJI Inspire 2 may receive an "inconsistent firmware" notification when using batteries updated with different firmware versions. This may lock the drone so DJI advises that pilots use batteries upgraded with the same firmware until a new firmware update is pushed out in December. This update will solve this compatilibility issue in addition to improving overall user experience.
Safety is DJI’s top priority which is why we implemented these conservative safeguards as a quick countermeasure to help prevent any further potential of M200 series drones experiencing loss of power mid-flight, while we continue our thorough investigation of the root cause of the issue and take further steps in the near future to remediate the issue.
These conservative measures, however, mean that some pilots may experience early and unexpected RTH or AL of their M200 series drone during operations as the batteries have been programmed to take an overabundance of caution when it detects even a small chance of battery failure or insufficient power to RTH/AL. During this interim period, we advise customers to plan their flights accordingly, allowing for the potential of an early RTH or AL function to be initiated.
DJI has prepared a user guideline to help minimize potential disruption to our users’ operations as we work around-the-clock to release the new firmware update in December which will further address these issues and improve overall user experience.
If you believe you may have experienced a related power problem involving the TB50 or TB55 battery, please contact DJI customer service at dji.com/support to report the issue.
