Will my burglar alarm still work if there is a power cut?
It should work fine.
There is a rechargeable back up battery within the alarm control panel which ensures that your Alarm System functions properly in the event of a mains failure. This should keep your system powered for at least 12 hours. When the power is restored the battery will automatically recharge.
Your installer will check the battery whenever a routine service is carried out.
DIY If you don't have an annual service visit it's quite easy to check the battery yourself. Every six months or so, turn off the electricity supply for a couple of hours and see if your alarm continues to function as normal. TIP It may be wise to do this during normal working hours, then if there is a problem you'll find it easier to get professional help.