Accenta G4 Alarm. Batteries/bell box still sounding

[Dora the explorer]

Hi I had a power cut and the alarm went off so I need a new battery in the panel seen on YouTube easy to change. So I turned the electricity to the panel off incase of any more power cuts its was 3.30am . Forgot to get battery today now the bell box is sounding..... Then the box has stopped sounding do I need a new battery in the bell box aswell? What order do I reinstate them?..... Will the alarm need reprogramming? If so is it easy or do I need my electrician.
Cheers

 

[Dora the explorer]

Okay so the bell box only stops for a short time and starts again... Its like a very loud chirping noise with an occasional siren

 

[Dora the explorer]

Anyone know how long the bell will ring its still going although quieter thanks

 

[sparkymarka]

Until you put the electric back on

 

[Dora the explorer]

The keypad wouldn't respond... Anyway the siren got quieter and quieter then the electrician sorted the bell box... Thanks