AURA Strap is powered by replaceable round coin cell (type CR2032) up to 6 months. To replace the battery you need:
1) Remove the backward cover with the included screwdriver (Philips PH0) сounterclockwise;
2) Remove the old battery and insert a new one with positive polarity upwards. Battery type is CR2032;
3) Place the cover and tighten the four screws clockwise.
4) Try to make a measurement