| > Evidently, AC waveform generation is extremely power-hungry I've tested a dozen models from APC. The inverter used in those devices uses roughly 15-20W with no load. Then for any load they have about 85% efficiency. Then you have further losses into any PSU connected there because they tolerate square waves but aren't optimized for it. So yes, in the end, less than 40% of the battery capacity in cheaper UPSes is actually usable. The reason you're seeing 20x is because obviously you've also greatly increased your battery capacity (typical under-the-desk APC units have 70-150Wh capacity, less than half of which is usable as explained above). > Overall power consumption with AC present dropped by about 40%. I'm finding that part harder to understand. The UPS consumes almost nothing when AC is on, so that can't be that. You've replaced multiple PSUs by more efficient, bigger ones, sure that can explain part of your improvement. But 40% drop is wild! |
Back in the 1990s, one could buy a "double conversion" UPS that converted AC to DC then back to AC, at all times. This was, supposedly, the best type of UPS (in my experience they were also the least reliable)