your £50 visit was cheap, £10 each for a sensor battery was dear
We'd be more than £104 & if non contract we'd might not come at all
By contrast
A daytime visit for my house telephone would be £120+vat if my equipment is not at fault
The business telephone line went off some months ago £450+vat for an engineer to attend on Saturday morning I declined, they fixed some days latter at the exchange (there a bunch of clowns)
I pay call costs & line rental.... you've provided no income for your alarm co. since the install
I'd change lithium radio alarm battery's every 2 yrs & the lead acid battery every 5yrs unless they fail earlier
In your case I'd **assume** the end station, radio expander & keypad ect... stopped working after 10hrs or so.
when powered back up it recharged its battery but shows L! for every radio device or something ? The batterys may not need replacing at this point but I'd expect who however replace them has measured them & found there down on volts?
Any fault with your CPX will appear in the log, view it ?