Two days later the second of these small APC backup UPC devices, an identical model, decided that the battery needed to be replaced (what, not even 3 years after initially installing them?). Except this UPS decided it wasn’t just unhappy but extremely pissed at me because instead of just sounding the beeping alarm and flashing the error lights it decided to temporarily, for about 5 seconds, pull the power from the server it was providing with current (it wasn’t running on batteries but on pass-through current).