We are continually working on improving battery life. One thing that may help in the meantime is using Dark theme, which was a top mobile request added to Teams mobile in February.
An error occurred while saving the commentPeter Gioia commented
An easy solution is to offer options to limit the times it checks for messages. Users can accept a trade-off of infrequent checking to save battery. Ideally I could check every 5 minutes during working hours and every 20 outside of working hours but any version of limiting battery usage would help.