One of my ei141 started beeping - so had to remove it from base. I will only be able to change the battery and place it back on the ceiling after a week or so, so the electricity supply for all other alarms is now also off. Can I turn it on (otherwise other alarms will start beeping soon without main supply) - when one of the alarms is not on the base? 

Hi

You can take the beeping alarm down and turn the mains power back on….meaning the rest of the alarms will still work when one is off its base.

Just be careful not to touch any of the live wires on the base plate without smoke alarm head.

Harry