How To Change The Battery In Ademco Vista 20SE

The Ademco Vista 20SE is an alarm system from ADT that comes with a backup battery that looks like this. The battery allows the system to continue providing security against fire, burglary and emergencies despite power outages.

Once the keypad displays “BAT” with no zone number, it means the battery power is already drained. This warning also comes with a beeping sound that can be turned off when you press [1 OFF]. The battery can be recharged through the house electricity but if the warning remains after 24-48 hours of charging, then you need to replace the battery. This replacement is usually required after 3-5 years.

These are the steps to replace the battery of the Ademco Vista 20SE.

Purchase the Ademco Vista 20SE.
Place the system on test mode.
Look for the control panel box in a closet, attic or garage. Open it to access the backup battery.
Disconnect the battery, starting with the black wire then the red wire. Remove the wires from their respective terminals using pliers with insulated handles. In case the wires are tight, wiggle it to loosen them. BE CAREFUL not to short the battery when removing it from the control panel box.
Remove the plastic terminal protector of the new battery before you connect it. Start with the red wire and connect it to the red positive terminal before you connect the black wire to the black negative terminal.
Close the control panel box.
Look at the keypad display if the warning “BAT” is still there. It is okay to let the new battery charge for 1-2 days. If the warning persists after the 2nd day, there could be a problem with the system. Get in touch with the alarm provider.
Recycle the old battery.