I just received my FR970 on December 15th. It has been updated to 15.33. Except for some transfers from my FR955, it's in the original system configuration. In particular, Low Battery Alert is off.
The watch regularly prompts to enable power saver mode. Typically, a few times a day for random percentages (98%, 84%, 48%, apparently the number 8 causes it. ;-)).
This issue was raised 4 months ago - Battery Saver Prompt after Update to 12.70 - Forerunner 970 - Running/Multisport - Garmin Forums - without apparent resolution.
Why is my FR970 prompting to enable battery saver when that functionality is turned off, and the watch has plenty of juice?!?