Solved UPS keeps cutting power to computer.

Does anyone know anything about UPSs? My UPS has shut down my computer unexpectedly a few times. Until a few minutes ago, I thought it was the computer doing it. The two times I've witnessed it, neither the power in the house flickered nor the other UPS (on another computer) made a sound, but my UPS clicks and beeps when it happens. It is a Cyberpower 900AVR. There is a PC Gadget for it that I can put in the sidebar. It says there are currently 162 watts but it has dipped to 145 watts of stored battery power. I ran the self-test and the result is "Battery capacity is critical". The gadget claims that it should be able to maintain power to my unit for 18 minutes, which is normal and the battery is full. My computer's power supply has more wattage than 162 watts.

It has been supplying power to my computer for a while. The only thing I have added is a Western Digital MyCloud, but that has been connected for a few months without incident. My power supply, which has a bad fan, has been running the computer with this UPS for years.

So the questions are:

Is the UPS itself going bad?
Are the batteries dying? I've changed them before.
Could the computer power supply be tripping the UPS if it is what's shutting down the computer?

Chances are the battery has reached the end of the line. You have another UPS so a quick test would be to swap them. But it sounds like the battery is on the way out. Every time A UPS of mine died it would beep and cut out for no apparent reason.

Sounds like you got your money's worth out of it.

I've always had trouble finding batteries for UPSs locally. If I can find which battery to get, I may get them from Amazon. It takes two. I've gotten them locally before, but I don't remember where.

AndyTampa said:

I've always had trouble finding batteries for UPSs locally. If I can find which battery to get, I may get them from Amazon. It takes two. I've gotten them locally before, but I don't remember where.

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How much do you save by replacing the battery? By the time my battery dies usually the box is pretty beat so I just buy a new one. But if you have the expensive power conditioning type of UPS then it may be a different story. I only bought the power conditioning type the first time. After that it was too expensive so I got whatever was on sale.

Apparently the UPS takes 12v/7.2Ah batteries. I keep finding 12v/7Ah and 12v/8Ah batteries. Would the 8Ah battery damage the electronics? Is it a different physical size? Does anyone know?

MilesAhead said:

How much do you save by replacing the battery? By the time my battery dies usually the box is pretty beat so I just buy a new one. But if you have the expensive power conditioning type of UPS then it may be a different story. I only bought the power conditioning type the first time. After that it was too expensive so I got whatever was on sale.

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The entire UPS is about $120. Replacement batteries can be found for under $20 each. It's cheaper to replace the batteries than to buy a whole new unit.

AndyTampa said:

The entire UPS is about $120. Replacement batteries can be found for under $20 each. It's cheaper to replace the batteries than to buy a whole new unit.

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It probably conditions the current then. Otherwise the UPS is usually less than $80 or so. I would look for a forum specific to the UPS. Usually the manufacturer has one. If not that then one that is for UPS type questions. Much higher chance the reader will have the specific experience such as you asked about the batteries.

MilesAhead said:

It probably conditions the current then. Otherwise the UPS is usually less than $80 or so. I would look for a forum specific to the UPS. Usually the manufacturer has one. If not that then one that is for UPS type questions. Much higher chance the reader will have the specific experience such as you asked about the batteries.

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I called Cyberpower and they don't sell batteries to the public. It is a two-battery pack that sells for around $90 from most who carry it. Cyberpower recommended I go to www.ReplaceUPSBattery.com to get it. Cyberpower said they sell the battery pack, but ReplaceUPSBattery doesn't sell it. They sell two individual batteries as a bundle for $32.62 and I found a 5% online coupon which makes the total price $30.99.

They arrived a couple hours ago and I haven't installed them yet. Looking inside the unit, I see two batteries wired together and taped with some very, very, thick, plastic handles to pull them out of the unit. It is a very tight fit. I'll have to remove the tape to disconnect the two batteries and reuse the tape and wires.

Well, I installed the batteries and reused the thick plastic handles. I don't know how many battery changes the adhesive will last through, but so far it's all good. However, sliding the battery pack in and out of the unit catches the plastic and tears it sometimes. At some point I'll be resorting to duct tape. I hope that doesn't melt.