How to Change a Home Alarm

Purchase a replacement battery that is compatible with the home alarm system. This information can be acquired from the installation manual that accompanies the system, or can be found on the manufacturer's website.

Call the security monitoring center's phone number if you are using a home alarm that is monitored externally. Instruct the personnel at the security center (once you have verified who you are and the location of the alarm system) that you will be replacing the battery in the control panel and so your alarm should be put in "Test" mode at their end.

Enter your passcode on the control panel's keyboard to disarm the system. Unplug the power cord attached to the control panel from the AC outlet it is plugged into. If the control panel is hard-wired to the electric line, pull the appropriate fuse or trip the appropriate circuit breaker in the fuse box to cut the power to the control panel.

Remove the screws on the side, top and bottom of the control panel with a Phillips screwdriver. Pull the top off the control panel -- if there are push tabs or a locking plate on the control panel, depress the push tabs and remove the padlock from the locking plate with its key first.

Locate the battery that is inside the control panel. If there is a compartment door over the battery compartment, open the door. Unscrew the tabs on each of the contacts at the top of the battery with your fingers. Remove the black and red wires connected to the control panel from around the contacts on the battery. In some cases, the tip of each wire will have to be pulled out of a hole in the center of each of the contacts.

Remove the battery and dispose of it properly. Place the replacement battery in the same position that the first battery was in. Place the black and red wires on the replacement battery's contacts in the same manner as on the previous battery. Screw the tabs onto each of the battery contacts. Close the compartment door over the battery if there is one.

Place the top back on the control panel reversing the way you removed it. Reattach the screws. Plug the power cord back into the AC outlet, or reinsert the fuse or trip the circuit breaker again to restore electrical power.

Enter the passcode on the control panel's keypad to rearm the alarm. If necessay, contact the security monitoring center to inform them that the alarm is now rearmed and they should take you alarm out of "Test" mode.