Cyberpower 725sl Shuting Off

I replaced the battery but it will shut down the computer when it loses power. Some times for no reason it will shut off. Sounds like the charging circuit has failed. Can it be replaced?

 

If the equipment purchase date is less than three years from today, they say "CyberPower will repair or replace a defective UPS system (including batteries) within three years of the purchase date.".

 

First, kudos to you for using a UPS. Every computer should be on a "good" UPS with AVR, regardless how stable your "grid" is.

Did it used to work just fine with that same hardware connected to it?

Note that 725VA is about 400W capacity. Not tiny, but not very big either. While 400W is typically plenty for most computers (even when stressed), if you have other devices connected to the UPS too (multiple monitors, a single CRT monitor, printers, network gear, speakers and more), you could be overloading the UPS. Things like speakers and printers (especially laser) should not be on the battery side of the UPS.

What cells (should have been two) did you put in there. They should have been two new 12V 9Ah. I am seeing 12V 8Ah suggested as replacements. While technically, the 8Ah should still work (though provide less run time), if the connected devices are placing a near capacity load on the UPS, you may actually need that little bit of extra current capacity during the cut-over.

The specs for that UPS unfortunately, do state the response time. Most UPS are able to respond to power anomalies in less than 10ms. This is normally plenty of time to prevent power interruptions. This is because ATX power supplies are required to "hold-up" output voltages for any power outage lasting less than 17ms. This of course, assumes the PSU is working properly.

If you have the correct replacement batteries installed (assuming you let them fully charge before testing them) I agree with Max and you should check the warranty. If less than 3 years, contact CyberPower. Otherwise, your UPS may need replacing.

Note I have 2 150W lamps I use to test my UPS. You might give something like that a try instead of testing with a computer.

 

Had one used on a cad/cam machine that had a wire pinched between the 2 parts of the case when put together. Was past warranty and had never been opened before. The wire was mis-laid in the plastic grooves provided causing a nick. Small wire and eventually the nick became a problem.