Weak powerline vs Underpowered PSU + weak powerline

[OpenSource Ghost]

I have a weak powerline in my house and can't change it for now. I also have a UPS, but it makes beeping sound when I load some intense games. It is very very rare, but it happens and for a few seconds. PC continues to stable during such rare beeps. That means my UPS is not powerful enough for my PC, but shouldn't UPS battery compensate for such instances and overall provide more stable power delivery than weak powerline by itself?

 

[kydsid]

How isn't it? Computer stays on right. I have a UPS with a laser printer on it, it beeps, indicating move to battery every time the printer starts. No biggie.

 

[cpufrost]

I have a weak powerline in my house and can't change it for now. I also have a UPS, but it makes beeping sound when I load some intense games. It is very very rare, but it happens and for a few seconds. PC continues to stable during such rare beeps. That means my UPS is not powerful enough for my PC, but shouldn't UPS battery compensate for such instances and overall provide more stable power delivery than weak powerline by itself?

First you need to check your incoming voltage at the outlet to see how far it sags under load. The issue may be your UPS is undersized and the beeping is to notify you that you're exceeding its maximum rated output. The battery is there to provide backup power in the event the input power is interrupted. Some units provide buck/boost function in that their transformers have windings that can be switched when over or under voltage is detected. An LED or display would show when this is happening. Even still, there are always limits to what a unit can deliver continuously.

How isn't it? Computer stays on right. I have a UPS with a laser printer on it, it beeps, indicating move to battery every time the printer starts. No biggie.

Hopefully the laser printer is connected to the wall and NOT your UPS! Only very large UPS units should be powering laser printers and those typically are not served by standard household 120V 15A branch circuits.

The reason why is due to the fuser heaters in the laser printers. They have a very high inrush current and the UPS isn't rated for this. On long branch circuits they will also cause noticeable nuisance flickering of lights (especially incandescent lighting) due to the high inrush current causing brief dips in the voltage. These dips will trigger the UPS to switch to battery periodically.