RING alarms and CCTV

i *think* Ring is the same as Blink cameras. The camera talks by wifi to a box hanging off the router and uploads to the cloud, provided both wifi and internet are available. The cameras themselves have long life Lithium AA batteries, but the other box is on a wall wart (so not too difficult to give it batteries, but you'd need to keep the router alive as well).

I don't have a Ring camera but am reluctant to sign up for a subscription to record to the cloud. After a trial period, it's £25 a year.

Another argument for Blink, which is still free AFAIK. Though I suppose that might change. There is only limited space, and it clears itself automatically, but there is always the opportunity to download specific recordings.