Nutloose, the battery ona is for use where it is not practicable to run power. It also means it can be moved around easily. I have just finished installing a mains powered, Alexa compatible one as well. By day there is no difference in quality of the image. By night the mains IR illuminator is about 3 times better.
I haven't compared detection ranges yet.
I find the cams very useful. Last week I only had an older one working. We saw a delivery driver leave a parcel 'in a secure place' when the instructions were to leave with a neighbour. Rang the neighbour who retrieved the parcel.