I have heard this fire alarm needing a battery change noise all day & thought nothing of it.
Yesterday, a new carbon monitor arrived & dh threw the old one into our kitchen bin (I know I know) & eventually the black bin bag went into the wheelie bin.
Our lovely neighbour has just knocked & said the alarm noise is coming from our bin & we all joked about wearing ear plugs as it's to dark & wet to do anything now but I have just been outside & from our neighbours side, nearer to our bins than where I sit it is really quite annoying.
The bag is at the bottom of the stinky weelie bin & it's dark.....