According to the latest report, Apple has released an updated firmware for the MagSafe external battery, which is compatible with the iPhone 12 and iPhone 13 models that support MagSafe accessories.
Starting today, the updated firmware should be released via OTA, and after installing the firmware, MagSafe External Battery users will see version number 2.7.b.0 in the Settings app.
Firmware updates are done quietly via OTA, and Apple doesn’t provide release notes, so it doesn’t know what features or bug fixes might be included in the software.
There is currently no explicit enforcement method to update the new MagSafe External Battery firmware, but it should initiate the update after connecting to your iPhone.
Apple last updated the “MagSafe External Battery” firmware last December, and the previous firmware version number was 2.5.b.0.