Battery lifetime varies on usage but eventually, you will need to replace the SmartCuff's battery.
You can always check if you need to replace the battery by taking off the sensor box’s lid either by unscrewing the top of the box or by popping off the lid off the box.
Next, take out the battery, wait about 30 seconds, put back the battery, and check if the led is blinking. If for any chance the led is not blinking, you'll need new batteries.
You’ll need 3V CR1632 batteries for a SmartCuff™ with an unscrewable box and 3V CR2032 batteries for a SmartCuff™ with a box with a poppable lid.
If needed, simply open the sensor box as explained above, take out the old one, wait about 30 seconds and then replace the old battery with the new one.
After you place in the new battery the LED on the blood pressure sensor's printed circuit board (right next to the battery socket) will start to blink, signaling a successful battery replacement.