What is the power consumption of UPS during a PC startup?
What is the power consumption of UPS during a PC startup?
Similar to around 50W or a bit higher. Unless your UPS battery isn’t completely charged, then the UPS battery charger will also start to charge the battery.
Without knowing the precise UPS make and model, it’s hard to determine exactly how much power the UPS charger uses.
But for PC PSUs, if you have a 760W PSU (which is quite high for its capacity), the initial startup of the PC uses about 50W, even without a full charge.
The PSU doesn’t always deliver the full 760W to the components at once. Instead, the PC parts (CPU, motherboard, RAM, GPU, SSD/HDD) request power from the PSU and then pass it on.
Suppose the PC needs 200W from the PSU. The PSU provides that amount, but because of inefficiency, the PSU draws more power from the UPS.
If your PSU is rated 80+ Bronze, it’s around 82% efficient under typical loads. At 20% load it’s 82%, at 50% it’s 85%, and at full load it’s 82%.
With a 200W demand on a 760W PSU, the actual load would be about 26% (about 82% efficiency), meaning the PSU extracts roughly 236W from the UPS. The surplus 36W becomes heat.
If you use a 80+ Titanium PSU, which is more efficient, the numbers change.
I’ll use my own PSU as an example. I have a Seasonic PRIME TX-650 80+ Titanium PSU [SSR-650TD].
This model is 94% efficient at 20% load, 96% at 50%, and 94% at full load.
At 200W demand on a 650W PSU, the actual load would be around 31% (about 82% efficiency), so the PSU would supply 200W to the components while drawing 210W from the UPS. Only about 36W is lost as heat.
My current PC is drawing roughly 78-85W from the UPS, while the UPS I own is: CyberPower CP1300EPFCLCD (1300VA/780W, pure sine wave, line-interactive).
Details about the UPS’s power draw aren’t listed, but if we estimate a charging time of 8 hours at 780W, it would consume around 97.5W per hour. Of course, battery charging isn’t constant, but for simplicity, let’s assume that.
During normal operation, the UPS might use about 5W. The display only lights up occasionally or when there’s a problem with the main power.