Xiaomi Smart Band 7 Manual Del Usuario página 21

Battery Safety
This device is equipped with a built-in battery that cannot be
removed or replaced. Do not disassemble or modify the battery
by yourself.
Disposal of a battery into fire or a hot oven, or mechanically
crushing or cutting of a battery, that can result in an explosion.
Leaving a battery in an extremely high temperature surrounding
environment that can result in an explosion or the leakage of
flammable liquid or gas.
A battery subjected to extremely low air pressure that may result
in an explosion or the leakage of flammable liquid or gas.