2500k+UPS Beeping

Today i got a Cooler master 212 plus, so i decided to do some overclocking, got it to boot no problems at 4.6ghz, ran prime, temps were fine, max was about 75c. About 5mins or probably less into the test, my UPS began to beep quite fast. I immediately shut off the pc, (kinda panicked lol. flicked the switch on the back on the psu off, wasn't sure what was going on.) This normally happens when there's no electricity, and it switches to batteries, and there about to die. My UPS is rather old and i assume the batteries are worn out because as soon as the power is cut its beeps loud and then shuts off. No batt life. I use it still for surge protection. Can someone explain whats going on here?

Thanks!

P.S sorry if i posted this in the wrong section...nt 100% sure where this would fall into

It sounds like when you were overclocking, you used more wattage and over loaded your UPS.
If you continue to have issues you can plug into the surge protection only if your UPS has one, or purchase a larger UPS.