As I've experienced a couple of power outages where I live recently, I was wondering if anyone here has experience with a UPS solution for the RPI. I've been googling and came across a number of options such as PiJuice etc, but I'd rather hear some real life experience and reviews. (FWIW, I run a Pi Zero W with a copper heatsink on the processor, height is approx 48mm)
Thanks in advance for your input!
I put all the network equipment on a full size UPS. If the router is down on power loss the Pi-hole is effectively down whether it has power or not.
Router, modem, switches, Pi-holes, NAS and home automation hub on the UPS.
You could use a simple powerbank
A simple powerbank isn't fit for the job: The RPi would just drain the initial load from it before failing, and it may never wake up or go into a loop of short periods of activity and outages afterwards.
You'd need at least a charge-through model that's capable of both charging itself and supply the RPi at the same time. In additon, some powerbanks may not even provide power at all to low amp devices like a Zero.
Also, jfb is right: In the actual event of a local power outage at your house, it's of little use to have just Pi-hole as the last device standing all by its own.
And a powerbank would still lack another feature of a proper UPS solution: Custom circuitry like PiJuice comes with the added advantage of allowing the RPi to shutdown gracefully before the battery expires.
Similar should be possible with regular UPS equipment, provided you find Linux support for your specific UPS, e.g. http://www.apcupsd.org/wordpress/about/.
Thanks for the replies so far!
Correct, the goal I had in mind is to avoid sudden supply outages negatively affecting the SD card. I can live with not having a working network for a bit tbh.
A charge-through device would then be the minimum of requirements if this would exist, with the capability to supply the low currents drawn by the RPI0W for a period of say 30 min - so say 0,4 Wh would be sufficient. The additional possibility of having a 'graceful' shutdown would then probably not even be needed, but why not.
Any experiences with a PiJuice?
$75 for a PiJuice puts it more expensive than many full UPS. Ouch.
A 1350 VA UPS is $85 US on sale.
That is what in my understand a powerbank is able to do. Charging & suppying at the same time.
Most powerbanks won't support charge-through, which is not surprising given the usage scenario they've been designed for:
They are meant to charge a portable device in the absence of power sockets.
When a power socket is available, you wouldn't need the powerbank - you could charge your mobile device straight from that one.
Even for those models that support charge-through, I doubt that they are meant to be operated under continuous load. I'd expect battery lifetime to suffer if they are.
Well, a graceful shutdown is the only reliable way to avoid that, and you won't get that with a powerbank solution.
Besides, you will get quite a few sd cards for the price of either UPS purpose gadget.
If you're really keen on this, I'd research available RPi-specific UPS solutions instead. They may not even be that much more expensive than a powerbank, and some may even offer additional benefits like a graceful shutdown power button. Cheaper models like Waveshare's UPS HAT may focus purely on UPS.
I have zero experience with those myself, but I recall German ct magazine has done a feature article on UPSs some years ago. Maybe that's still available. 
Im using an 12 Volt inverter a $5 car battery and charger.
Did a test today it lasted over 30 mins to approx state of charge 50% of battery.
I like your setup @smokingwheels
What inverter are you using and where could you get a decent battery for $5?
The inverter, was about $35 off ebay.
The Battery, I put a wanted ad on local buy and sell on Facebook for old car batteries.
The charger, is a pulse repair one approx $35 off ebay.
