12V 8Ah Compatible Battery for APC Back-UPS CS 500, BK500, BK500BLK

I installed this battery as a replacement into an APC CS 500 Back-UPS on Feb. 20, 2018. When I came into the office on Oct. 12, 2020, the unit was squealing and in fact would not stop until I unplugged the unit and removed the battery completely. The manufacturer indicates that this battery has a long life. I would have expect perhaps another six months to one year of longevity, but for the price still can't overly complain about the battery's service life. The APC unit was plugged in continuously to protect a PC that was minimally used during this period, perhaps three for four hours per day for no more than four days per week.

The price for the battery is very low and after easy installation, it works without any issues. I've not tested how long it would hold the charge after no power but I believe the time will be sufficient enough to safely shut down connected devices. It was never intended to be the power source for a very long time anyway.