Short answer
Most wired alarm panels use a 12-volt sealed lead-acid (SLA) battery, usually 4 Ah to 7 Ah, inside the metal cabinet. Put the system on test with your monitoring company, open the cabinet, move the red and black leads from the old battery to the new one (red to +, black to −), close it up, and give it up to a day to charge and clear the low-battery message.
On this page
Before you start
- Call your monitoring company and ask them to put the account on test. Opening the cabinet can trip a tamper switch. See putting your system on test.
- Have your code handy to silence any beeps.
- Leave the AC power plugged in. The panel stays running on mains power while the battery is out, which avoids a full power-down and losing the clock.
Get the right battery
Read the label on the old battery and match it:
- Voltage: almost always 12 V.
- Capacity: commonly 4 Ah, 5 Ah, or 7 Ah. Going up in capacity is usually fine if it fits in the cabinet and the panel's manual allows it; going down shortens backup time.
- Terminals: F1 (narrow, 3/16 inch) or F2 (wide, 1/4 inch) tabs. Match the old ones so the leads fit snugly.
Touchscreen all-in-one panels (2GIG GC3 and Edge, Qolsys IQ, Honeywell Lyric and Lynx) use a different, model-specific internal battery pack, often lithium-ion. Order the manufacturer's replacement pack for your exact model instead of a generic SLA battery.
Swap the battery
- Open the panel cabinet. On most it is a key lock or a screw on the side of the door.
- Note which lead goes where: red to positive (+), black to negative (−).
- Pull off the black lead first, then the red one. Do not let the bare red lead touch the metal cabinet.
- Lift the old battery out and put the new one in the same position.
- Connect the red lead to + first, then black to −. Push the clips fully onto the tabs.
- Close the cabinet and clear any trouble beeps with your code.
Never reverse the leads. Connecting a battery backwards can blow a fuse or damage the panel's circuit board.
How long until the warning clears?
A new battery arrives partly charged. Most panels only re-test the battery periodically, so the low-battery message can stay for anything from a few minutes to about a day. If it is still there after 24 hours, check that the leads are tight, the AC transformer is plugged in, and the battery is not a dud (a meter should read roughly 12.6 V or more off the charger). A battery that keeps going low quickly can point to a charging problem in the panel.
Recycle the old battery
Lead-acid batteries should not go in household trash. Most auto parts stores, battery shops, and municipal hazardous-waste sites take them for free.
How often to replace it
Plan on every 3 to 5 years. Heat (attics, garages) shortens battery life. Writing the install date on the battery with a marker makes the next swap easier to plan.