Not that it matters too much but the typical resistance range for an LDR can be from 1M (darkness) down to 100 ohms (bright Light).

 

Is it any concern that when the adapter power goes off you will have just over an hour with the 9V battery?

 

certainly that is not ideal but i can go with a 600mah one to get a decent usage. beside that i don't know any other 9V source that would be a suitable replacement unless you have something in mind. it just need to be 9V and compact.

 

certainly that is not ideal but i can go with a 600mah one to get a decent usage. beside that i don't know any other 9V source that would be a suitable replacement unless you have something in mind. it just need to be 9V and compact.

Probably a hair over 2hrs.