Security & Fire Protection Systems/XL-2 with XL4600SM Keypad


My system is over 16 years old with no problem up to this time. My AC/LB light was flashing and I replaced the battery. After the replacement I'm getting the flashing AC/LB light. I also will get an alarm which I can turn off for a short time, about 5 minutes, After which the alarm will go off again. I've tested the system and rearmed the system.This seemed to work correctly.

Do I have a power problem? Could my new battery be bad?

Depending on where you purchased your battery and the conditions it was stored in, it could have discharged sufficiently to activate the "low battery" circuit on your system.  If you're still experiencing the problem after 24 hours, then we'll run some additional diagnostics on your charging circuit and battery.  You'll need a DC voltmeter for this.  Let me know.

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Frank Kurz


Questions relating to Burglar Alarm and Security Equipment, Fire Alarm and Extinguishment Systems, Access Control, CCTV Systems, Installation, Service, Testing, Verification


30 years installing, servicing, and testing security, access control, extinguishment, and fire alarm systems

Chair of ULC Working Groups for Fire Alarm Testing (CAN/ULC-S536) and Fire Alarm Verification (CAN/ULC-S537), Executive Director of the Fire Protection Technicians Network (

Publications, Better Business Bureau Magazine, Applied Science Technologists and Technicians of British Columbia ( SUPPRESS! and Techs Fire Break Newsletters

Associate in Science; Emergency Systems (University of British Columbia); Aircraft Maintenance Technology (BCIT)

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