When it is time to replace the battery in your door/window sensor, you will see an alert on your system panel, as well as a notification in the alarm.com app
The DSC PG9303 door/window sensor requires a 3-volt lithium CR2450 Panasonic battery, which can be purchased at your local hardware, mass retailer, or battery store.
Step-by-Step Instructions:
1. Locate the sensor with a low battery on either your system keypad or App
2. Open the cover by inserting a coin into the slot, then twist to remove. If a coin is not available, insert a 4mm flat screwdriver into each slot of the plastic cover, then twist to open each side.
5. Place the cover back on starting with the opposite end from which it was opened. You should hear a snapping sound if it closes correctly.