Alas things have not been going too well with my plant waterer project.
It needs a hefty power supply to drive the pump and solenoids.
As it will only need to run once a week (maybe), or "infrequently" I am thinking of being stingy with the power.
Instead of keeping it connected to the mains all the time, I was thinking of a small battery for when it is not doing the main work.
I have a 5 volt relay which is mains rated on the contacts, so that is a bonus for me. I'll explain in a second.
Idea: As most of the time not much is happening, a battery runs the "system" - which only needs to be the Arduino and RTC. When "time x" happens the Arduino puts a pin high and turns on the mains. It waits a while then does what it needs to do. Waits a while again then turns off the mains.
In theory that sounds easy, but I am wanting to ask if there are any problems I am not seeing in what I have explained.
Thanks in advance.