CyberPower 1350AVR UPS Failure
The UPS I bought years ago at Costco seemed to go on the fritz: the display was blinking nonstop, and it seemed like it was cycling the power on some of its outlets, even. A stereo amp plugged into it would periodically turn on during this, as if it had freshly been plugged in (as it is normally dormant, alive when newly plugged in, turned on, or sensing a signal in). The LG 55" C9 stayed on without issue. All of the devices plugged into the UPS were actually plugged into the surge-only outlets rather than the battery backed outlets, as (weeks earlier) the power was cut during some bathroom remodel work that drained the battery, with items plugged into the battery ports dead even when the power was restored and the UPS was powered on (making me think the battery backed ports were nonfunctional when the battery was 100% dead, I suppose?).
The UPS behavior looked like this:
I wasn't sure if the UPS itself had failed, or if this was behavior that would be explainable by the end of life of the batteries within the UPS. I'd replaced the batteries several times in a prior UPS, but this unit is on its original set (years old at this point...surely 5+ years), so I've never seen this unit during battery failure.
Searching online, I found someone else describing the exact same behavior: https://blog.sherwinm.com/2017/08/05/replacing-battery-on-ups-cyberpower-1350avr/. Besides seeing the behavior, this personal also talked about how they went about replacing the battery: an OEM CyberPower battery is $70-80, which is a half of what the entire unit costs new. They ordered an third party replacement at https://www.replaceupsbattery.com/CyberPower-RB1280X2A-Batteries-Set-of-2/. It's less than half the price of the OEM battery (with free shipping, too), and the person at this first link swapped it in and has been running fine. The standard warranty is 1 year (shorter than the OEM 18 months), but a $3 more buys you a 2 year warranty..and you're still less than half of the OEM price. Shipping from outside of Texas with no local presence, there was no sales tax either.
I ordered on a Sunday, it shipped on Monday, and arrived the next Monday. Swapped it in and...back in business. It's not as straightforward as the currently-linked product documentation suggests, though; mine is CP1350AVR, but the version of that model linked on the CyberPower website is this: https://www.cyberpowersystems.com/product/ups/intelligent-lcd/cp1350avrlcd/. The user manual linked there shows the removal of two screws in the bottom, with half of the side of the unit sliding off to reveal both batteries. What I found was instead one screw newer the bottom front, with a faceplate that slides off. The pair of batteries inside are wrapped in clear plastic tape with some extra coming towards the faceplace, giving something to grab onto to slide them out. My first inkling of there being a design refresh of the CP1350AVR was when ordering the batteries: it Replace UPS Battery directs you to one battery set if your serial number begins with one sequence, and a different battery set otherwise. The newer design certainly seems like an improvement over mine (easier access to the batteries, no need for a special joining plate, and no need for the tape pull).
Removal videos for the new version are like this:
Whereas I found some guidance by watching someone use mine:
and especially this one:
This video is for the 1500 AVR, but the physical design is the same and these just use slightly higher capacity batteries. I'd also found someone doing my same generation 1350AVR, but he cut the video when removing the batteries, which I needed to see, as it was a struggle. The trick for me was to pull them out with the batteries closer to the ground and the wires coming from the case on top of the batteries; I think when the wires are on the bottom, the weight of the batteries pressing down on them results in more friction and a much harder time getting the batteries to slide out.
After reassembling things with the new battery, I plugged the unit back in and powered it on. It passed its self test fine, and shows an icon for 'Normal'.