I was siting here earlier, dinner (BBQ) was over, we had cleaned up and the power went out. We do not have many power failures here. I am in a big city and the infrastructure is here to keep power on.
I have two computers, one AC powered Desktop and one Battery powered laptop. I have a sturdy UPS for this and networking gear (modem, router, Wi-Fi) in the basement.
I waited 5 minutes and turned the desktop off. The laptop was fine on battery.
After 15 minutes, I start looking around because the UPS is beeping unhappily.
After about 30 minutes, I go downstairs and realize an old monitor in on (standby) and I flipped it off.
The cable TV box is ON (it has its own UPS). It takes it more than 30 minutes to fully load and start.
After about 45 minutes, we went out walking, up to the top of the hill and realized the outage was very widespread.
We get home and power remains off.
After an hour and 45 minutes the power comes back on.
1. TV Cable Box is fine.
2. Both clocks in our bedroom come on to the correct time (battery backup)
3. Train DCC controllers come back up with no loss of settings.
4. Thermostat stays on throughout (battery backup).
5. Outside lights and time-zone controller are working (battery backup for the controller).
6. Phones stay on. New iPhones have excellent battery life and don't need Wi-Fi
It is amazing, really, how many things can pick up where they left off after a lengthy power failure.