What I meant was if the (mains adapter) power supply feeds one of the easily available mobile devices battery back-up / charger units which in turn the Pi is connected to.
Would this not give several hours UPS ?
I was testing power bank some time a go. Good one, not the cheapest. It was not working. It could be in charging state, or powering your phone.
This mean. When it was charging itself, then it was not put power to the phone.
Power bank is not DC UPS. Ofcourse there is planty of them, or even more than planty, some of them could work as DC UPS I believe, but I don't know unit which could do that.
So I can't recommend power bank.
I am testing now two units of DC UPS, both are working fine:
This oneand this oneFirst one has only one LiIon cell, but it is very easy to use. Just plug to electrical outlet.
Second has 3 cells, so we could say that it is 3x capacity of 1 one. It comes without AC adapter. You need to have 12v, probably 1A AC adapter to use it.
I am testing them. I will write test results on WXForum. I will also ask Ryan to have it in his shop, to provide best customer service, not like this from China websites.
Ryan has also USB to Davis console cable, which is needed.