Several times per month my SBP will completely power off when being used as a UPS. After a few moments the screen comes back on and shows the battery at 0%. After another minute or so, the battery will suddenly start to steadily climb by 1% every second until it returns to full capacity.
The whole reason I decided to purchase this battery over competitors was for it's claimed UPS feature. It's literally been worse than having no UPS feature, because it does this periodically and completely cuts the power to anything that is plugged into it, even when the battery itself is directly connected to the wall outlet and fully charged at all times.
Something else I think is really poorly thought out: The option to set the SBP to stop charging once it reaches the battery percentage specified doesn't even work while in UPS mode. If anything, this is the most important time for said feature to even work. The way it is now, the thing is always at 100% battery when it's being used as a UPS, greatly shortening the lifespan of the product. Or is that intentional?