Pyronix PCX256 battery fault

[Neil Sutherland]

My alarm was showing a Battery Fault 100 error, so I replaced the battery and all appeared to be well initially. However, after a few hours the Battery Fault returned, and shortly after that Low Volts. I'm wondering if there's a PCB fault that's discharging the battery? Any ideas please?

 

[Bigsosij]

What are the battery and charging voltages

 

[Handymanjo]

Check battery fuse.
Where did you get new battery from ?
Not the first time new battery could be flat or fault,could have been on shelf for some time.