Battery stuck in bootloader mode due to failed firmware update

Modified on Wed, 7 Aug at 2:57 PM

Lithionics BMS firmware can be updated using Lithionics Battery Monitor app on your mobile phone or tablet. Update is loaded via Internet connection into the app and then via Bluetooth connection from the app to the battery. During this process the battery is in Bootloader Mode, a special state which allows flash memory update.

Firmware update is a sensitive process, so it should be avoided when you are camping and relying on battery power. It's best to wait until you have a good grid power connection and a strong Internet connection.

It is critical that Bluetooth connection stays strong and steady during update, which requires your phone to be as close as possible to the battery and that you disconnect any other Bluetooth devices from your phone, such as headphones or speakers, etc.

If Bluetooth connection is weak or interrupted during the update, your battery will be stuck in the Bootloader Mode until you repeat the process without interruptions. In some cases of multiple unsuccessful attempt you may want to try using a different mobile phone, ask someone else to use their phone to try and finish the update.

Note that Bootloader Mode has a 2-3 minute timeout, during which the LED is flashing. If you wait 2-3 minutes the battery will go back to normal operation, so you can either repeat the update from the start, or wait until later. However, if you power cycle the battery it will go back to Bootloader mode until the update is successfully finished.

How to recognize a failed firmware update? You will see "Failed" at the bottom of the Log window, see below example.

You can press Update Firmware again to repeat, but first try to bring your phone closer to the battery.

How to restart the update from another device or if I closed the app? Try to connect to the battery as you normally do, but expect to see this prompt if the battery is still in the Bootloader Mode after the last failed update attempt. Press OK to get back to Firmware Update screen, then press Update Firmware button to repeat the update.