Hi all,
The charging situation is even worse with my Jackery 240 power station - it charges at a rate of 39W from its power brick (but can charge at a somewhat higher rate from higher voltage supplies like solar panels). I think other Jackery models are better about this. (note: the cheaper Jackery 160 is not a true sine device, and can't charge and be charged at the same time)
The good news is that equipment pulls far less power at idle than the nameplate rating. My S950 pulls about 10W at idle, if I remember right. The onboard digital amplifiers are very efficient. Plus I have a Behringer UMC404HD that pulls a tiny amount of power, and if I have the StagePas 400i sound system hooked up, it pulls about 30W at idle. So, those things combined, I'm not quite breaking even, even in the best case. But I don't use the power station for continuous UPS protection 24x7; instead I use it just when I need it. (we use it for non-music purposes, such as when out camping/etc, which was the original reason we got it)
Be sure to compare watt-hours rather than amp-hours, as amp-hours is dependent on the voltage in question. For example many small power banks output 5V over USB, but the labeled Ah rating is based on the 3.7V internal Li-ion battery. So the Jackery 240 is a 240Wh device, and operates at about 85% efficiency, giving 204 net Wh at the output. The CP900AVR has two 7Ah 12V batteries, giving 168Wh internal, but it probably only operates at about 50% efficiency for 84 net Wh.
Line-interactive UPSes like the CP900 are designed to be operated 24x7 but very infrequently on battery, and their lead-acid batteries like being kept at full charge (so keep the UPS plugged in even when you're not using it). A power station like the Jackery is designed for portable intermittent use but mostly on battery, and you'll get the most life (years) out of its Li-ion batteries by keeping them at about 50%-70% charge when in extended storage (but every couple of months do a full charge cycle).
Some lower-end UPSes also sometimes cannot be manually powered on in the absence of AC line power.
Double-conversion UPSes having a true sinewave output are more expensive, but are more well suited for sensitive audio equipment, when compared to modified-sine line-interactive UPSes.
So which route you choose (power station vs UPS) really depends on your use case - stationary backup power for the occasional power glitch, or else needing to be more portable or operate completely off-grid, either due to storm activity or because there's no AC power nearby.
For UPSes, I've tended to like APC, Liebert, and Eaton more than Tripp-Lite and Cyber Power. For lead-acid UPS batteries I currently like the CSB HRL series and often order from OSI Batteries when I need a bunch of them.
- Greg