The Autel EVO II Troubleshooting Guide
DroneLogix has hundreds of hours of logged flight time flying the Autel EVO II series platforms, both Pro and Enterprise models, and both V2 and V3 models. Below are insights that we have learned from flying and maintaining these aircraft.
Additional Resources:
Autel Support: Call +1 (844) 692 8835 or send email to support@autelrobotics.com
EVO II Enterprise Series Downloads
EVO II Enterprise RTK Series Downloads
EVO II Enterprise Dual (Thermal) Series Downloads
EVO MAX Series Downloads Note: The EVO Max firmware and the app can only be updated through OTA(Over-The-Air) methods.
EVO II Enterprise V3 Maintenance Manual
Explorer App Message: "The firmware can't be upgraded while the device is charging"
This message appears when attempting to upgrade the aircraft firmware while the charging cable is plugged into the remote controller.
Resolution:
Simply close the error dialog by clicking "Ok", if visible, and then unplug the charging cable and click the "Start upgrading" button. When the Information dialog opens that is titled "Wait upgrade..." you may then reconnect the charging cable. This will continue to charge the Remote Controller during the firmware upgrade process.
Explorer App Message: "failed to obtain device list" message
We noticed this message on a couple of V3 devices in our fleet when using the 7.9" Smart Controller while attempting to update the device name. This appears to be an issue for aircraft running the Autel Explorer app version 3.1.49.
Resolution:
The Smart Controller should be connected to its aircraft during this process, so power on both devices. On the Smart Controller, go to Settings (swipe up from the bottom of the screen and press the circle), go to Apps & notifications and then select the Autel Explorer app. On the App Info page select the three dots in the upper right corner and select uninstall updates. Click on OK when the dialog opens that asks you to "Replace this app with factory version? All data will be removed." Go back to the Autel Explorer app click on the Profile icon in the upper right corner of the main screen and log in to your Autel account. After login, you should be able to navigate open My Devices and see your aircraft serial number and bound email information. You can change the device name by clicking on the edit icon next to the device name at the top of the page. After confirming access to your aircraft in My Devices, click the Camera button on the main screen and navigate to the settings area (gear icon in upper right of screen) and select the General settings page . Click on Software Update and select APP and update the software to the latest version. Following the update, reboot both the aircraft and remote controller and confirm you can access the aircraft data in My Devices.
NOTE: If you previously installed the firmware that is associated with the upgraded Autel Explorer app version (in this example the APP version is V3.1.49), you will not need to reinstall the firmware on the aircraft.
Gimbal Automatic Calibration Fails
This particular problem was present on earlier firmware versions (Year 2022 - Version 2.3.23 and earlier) of the EVO II Enterprise V2 6K model, then it was introduced on the EVO II Pro around July 2022 (version 2.7.35). We experienced this using the 7.9" Smart Controller and the 6K gimbal, so it may not be an issue with iOS or mobile Android versions of the Explorer app or other gimbals.
Resolution:
Before a software update was available, the workaround was to remove any third-party filters (i.e. Freewell filter) on the camera lens prior to performing a gimbal automatic calibration, then reinstall the filter after calibration success. This bug was fixed in 2023 by a firmware update.
Explorer App Message: “Your remaining server space is less than 28.0MB Click Continue, your earliest records will be deleted.”
This occurs when your flight record data volume has outgrown the allotted Autel cloud storage associated with your Autel account login credentials and you attempt to sync your flight records from your device to the cloud. Clicking on Continue causes the sync process to fail. Clicking on Cancel cancels the sync process, as expected. When you experience this condition, your flight records stored on the remote controller will not sync to the Autel cloud and therefore your third-party aircraft or flight management software (e.g. Airdata, Dronelogbook, etc.) will also fail to sync and load recent flight data. Additionally, multiple attempts to run the sync process during the same session returns errors with the server space number bouncing around from 28.0MB to 20.0MB. The number is different almost every time and it goes up and down during this session.
NOTE: This condition has nothing to do with local remote controller storage space, so don't waste time trying to analyze local storage.
Resolution:
Contact Autel Support at support@autelrobotics.com and request that they increase your cloud storage space size for flight records for your Autel account. When your Autel account's cloud storage runs low, you will experience the above error. You will need to supply them with the email address you use to login to your Autel account. They should make the change within a day or two, however, we have experienced delays up to five days. In the interim, DO NOT “Clear Local” data since the locally stored flight records are not yet synced to Autel's cloud storage.
Explorer App Message: "mission failed to upload" message
For RTK Missions: Some pilots report experiencing this issue when flying a defined mission using the EVO II Enterprise V3 with RTK after a battery swap occurs during the mission. To avoid this message, you need to first make sure your RTK fix has been completed and your drone is fully ready for takeoff before attempting to resume the mission. The Autel Explorer app does a poor job of managing the workflow needed to avoid this problem, so you should follow the "Suggested Workaround..." steps below to avoid the error condition.
For Standard Missions: Some pilots have reported this error when attempting to fly missions using an EVO II V3 (without RTK), and it appears to be an ongoing Autel Explorer bug. As noted above, you need to always make certain your aircraft is ready to fly (GPS status is good/excellent, RemoteID is normal (for US pilots), gimbal is ready, and battery power is above the minimum needed to fly) before attempting mission flights. Autel's software quality control is weak and they are known for releases where prior bugs are reintroduced. The recent Autel Explorer update (November 20, 2024), version 3.1.117 that targets the Smart Controller, and aircraft firmware update, version 1.2.7, indicates it "fixed occassional mission upload failures". If you experience this error repeatedly and you have updated to the latest app and firmware, it is recommended that you reach out to support@autelrobotics.com and request assistance. They may provide another version for you to install that may resolve this issue. In our experience, we usually request a hot-fix for mission-critical bugs and they often will work to supply such a fix.
In the past, downgrading to a prior version has also resolved this issue, but you also lose the benefits of other bug fixes and new features when you take this course of action, so reaching out to the Autel support team is usually best.
Suggested Workaround For RTK Missions
After the battery swap and before restarting the aircraft, return to the Autel Explorer home screen on the remote controller.
Now restart the aircraft. When the aircraft initializes and you see the prompt to resume the unfinished mission, decline the prompt and then select camera mode.
After you see the aircraft sensor image on the remote controller, reconnect to the RTK service (because it doesn't login automatically). The RTK status must show "FIXED" before continuing. If needed, revisit the RTK settings and verify your credentials are entered which will trigger the drone to attempt to connect to the RTK network, and wait for a fix to be obtained.
After the RTK fix is confirmed, go back to the Autel home screen and then back into the mission you wish to resume.
When ready to fly, press the Fly button and select Resume to continue with the mission that was interrupted by the battery swap. The mission should upload successfully and the aircraft should take off and fly to the last waypoint and resume the mission.
Smart Controller V3 Fails to Pair with the Evo II Pro V3
This occurs when the Smart Controller fails to upgrade properly, even though the firmware upgrade process reports success. This condition can occur for all editions of the EVO II, both Pro and Enterprise. Essentially, the Smart Controller Remote Control firmware gets stuck on an earlier version (e.g. V6.0.2.0) instead of upgrading to the newer version (e.g. V6.0.2.6) during the upgrade process. There is no indication of an error during the upgrade process. If the remote controller's firmware version does not upgrade properly, it will be unable to communicate with the V3 EVO II Pro (or Enterprise) that is running a newer or different version of firmware. Review the Firmware Version Table information found on the Autel Robotics downloads page to understand and compare version numbers found in the table with those shown on the Remote Controller. In our case, we were upgrading from V1.0.10 to the latest V1.1.9 (EVO II V3) firmware during June 2023. The Smart Controller we upgraded over-the-air (OTA) to V1.1.9 upon receipt, but the Remote Control portion of the firmware package did not upgrade properly. Consequently, we could not bind the Remote Controller with the aircraft, even though the two devices could communicate together out of the box.
Resolution:
Short Instructions: Downgrading the firmware, pairing/binding, then upgrading to the latest firmware resolved the issue.
Detailed Instructions:
NOTE: You may need to engage Autel Support at support@autelrobotics.com for assistance with securing a copy of the previous firmware version in order to complete the steps below. They closely manage access to firmware, so we recommend that you share you are unable to bind your aircraft with its remote controller after performing a firmware upgrade. As part of our firm's best practices, we maintain a copy of each firmware version and details when released.
We will be downgrading the aircraft firmware to the earlier version (in our case, V1.0.10) using the correct version file supplied by Autel or that you may have saved from earlier updates. Once your aircraft is downgraded, we will then do the pairing mode on the aircraft and smart controller. Once they pair, you should then receive an over-the-air (OTA) firmware update notification to upgrade to the newer firmware version (in our case, V1.1.9).
In our case, we were attempting to pair to a Smart Controller 7.9" device, not the Smart Controller SE device that shipped with the aircraft. For this process, we did not utilize the SE controller at all. If you are in a similar situation, please leave the SE controller off.
Here are detailed instructions for a manual update:
BEFORE YOU BEGIN: Make sure that both devices have at least 80% battery power before performing the update process to minimize this risk.
- Download the firmware zip file and copy it to the root folder (no sub-folders) of a Micro-SD card. DO NOT unzip it.
- Power on the aircraft and the Remote Controller. They will not be connected in this particular case.
- Insert the SD card into the aircraft, and the firmware update process will start automatically. You will see the aircraft LED indicators rapidly flash. Nothing will indicate on the Remote Controller since the two devices are not connected.
- Wait about 30+ minutes, and you will see the aircraft LED indicators become solid, indicating the firmware update has been completed.
- After the aircraft update is completed, power cycle the aircraft and Remote Controller. We will do this step whether or not the update passes or fails. If the update fails and the remote control refuses to connect to the aircraft after following these steps, contact Autel Support, because there will be a new set of instructions for you to follow if this happens. (It is not typical that the update fails and then doesn't connect.)
- If the aircraft and remote controller indicate they are connected, you should receive an over-the-air (OTA) firmware update notification to upgrade to the newer version. Perform the update, power cycle the aircraft and Remote Controller and confirm they are able to connect and communicate.
What About Non-Autel, Aftermarket Batteries?
Autel EVO II series batteries work across the full EVO II line, both Pro and Enterprise models, including 6K, 8K, RTK and Thermal models, for V1, V2 and V3 series. We are not aware of any non-Autel, aftermarket batteries, but should you buy one or have a battery rebuilt using third-party cells, you should never use a non-Autel battery for drone flights. Third-party batteries would be fine for ground activities such as gimbal calibrations, IMU calibrations, firmware updates, or powering ancillary devices or charging your controller in the field when using a special cable designed for this purpose. For flights, only use an original equipment, Autel-manufactured 7100mAh Intelligent Flight Battery, part number AR-EV2BT. Flights made with a non-Autel battery that result in a crash will void the aircraft warranty, including coverage under Autel Care Refresh.
Fly safe!