Learn how to install or replace a battery in the Visonic MCT-320 SMA door or window sensor.
What you'll need
- Xfinity Home
- MCT-320 SMA door or window sensor
- A flathead screwdriver
- One CR2 battery
- Double-sided tape (optional)
Difficulty
Medium
Do you need a battery?
Make sure you have batteries before you proceed. Visit your nearest retail store that sells batteries or click the button below to order your replacement battery kit.
Call us at 1-800-XFINITY if you receive a low battery alert within 30 days of device installation.
Install the battery
Before proceeding, make sure that your system is disarmed. Working on devices while the system is armed can generate false alarms.
Did you know? You may want to have some double-sided tape on hand if you need to remove your sensor from the wall to install a battery. Use the tape to reattach your sensor if its existing adhesive fails to hold it in place.
Help protect our environment: Please properly recycle your discarded batteries. For your convenience, batteries are accepted for recycling at various locations. Check call2recycle.org or call 1-800-8-BATTERY (1-800-8-228-8379) to find a recycling location near you.
Is this your sensor? Make sure that your sensor looks like the one in the image below. If it does, you're in the right place to find out how to install a battery in your sensor.
To install batteries:
- Locate the small slot on the right side of the sensor by following the slim cut-out design on the middle of the sensor until it becomes wide.
- The slot is at the end of the wide cut-out next to the magnet indicator.
- Did you see? There is a tab located on the narrow side of the cut-out that shows the location of the magnet for the sensor (see arrow above).
- This sensor only reads the tabbed magnet.
- If the magnet is not lined up properly after you've replaced the battery, your sensor won't react to open or closed events.
- The slot is at the end of the wide cut-out next to the magnet indicator.
- Insert a flathead screwdriver into the slot and gently turn the screwdriver clockwise to pop open one side of the battery cover.
- After removing the cover, you may receive a tamper alert from your system.
- The tamper alert warns you when the cover of your device is open and will clear once the battery is replaced and the cover is reattached.
- Locate the small slot on the opposite side of the sensor.
- Insert a flathead screwdriver into the slot and gently turn the screwdriver clockwise to release the cover from the sensor's body.
- Take a look: If a battery is already present, remove it by using your fingertip to gently pull one end of the battery up until the battery is loose and you can pull it free from the slot.
- Insert a flathead screwdriver into the slot and gently turn the screwdriver clockwise to release the cover from the sensor's body.
- Locate the positive (+) and negative (-) battery placement indicators inside the sensor's body.
- Be sure not to press down on the tamper (blue square) when inserting the battery as this will reset the sensor to the factory settings.
- Be sure not to press down on the tamper (blue square) when inserting the battery as this will reset the sensor to the factory settings.
- Insert one CR2 battery into the slot, matching the positive (+) end of the battery to the positive (+) placement indicator.
- When the battery is inserted correctly, the red light inside the sensor will light up.
- If you're replacing the battery, confirm that the low battery alert has resolved and the sensor appears on your list of connected devices in your touchscreen or the Xfinity Home app.
- Align the small tabs on the side of the cover with the guides on the sensor's body then gently push the cover onto the sensor's body until it snaps into place.
- If you're replacing the battery, test the sensor to confirm that it is working correctly.
- If you're replacing the battery, test the sensor to confirm that it is working correctly.