PowerStarHC1221W CSB Battery for APC ups RBC21 BF500 500U 400C

Battery size fits the Cyber Power 550VA UPS enclosure. Worked well and kept a PC and 2 monitors running during a 30 minute power outage.UPDATE: The battery worked well for about 7 months then went dead....wouldn't hold a charge for even 30 seconds after the power went out. Charging all day doesn't help either. Became useless as a UPS, but still functions a surge protector.

The battery was correct for the BF500U UPS and it appeared to work for a couple of days, then the UPS alarm started even though nothing was plugged into the UPS. Note that the UPS was plugged into a normal wall outlet and everything appeared fine for a couple of days, i.e., the green light was on and none of the other lights were on.I turned off the UPS to stop the alarm and then an hour or so later the "replace battery light" came on, but this should not have happened with a new battery.Bottom line, not worth wasting any money on this item. And, because it is a sealed battery it cannot be returned apparently. Now I still have an APC UPS that I cannot use because of a dead battery.

Took awhile to find a battery to fit my old backup power supply but this company had what I needed at a good price. Fit perfect and so far working well.

the battery it replaced lasted 9 years where as this one only lasted 10 months

I bought this to replace the sealed Pb-acid battery in a slim UPS system.The size was exactly correct, and the connectors in exactly the right location to make the replacement easy and successful.

I’m writing this review after purchasing this in September of 2017. The battery just died this past week. This is a ups a have mounted on the wall in my non-climate controlled garage. I live in the southern U.S. so the temperature would occasionally dropped to below freezing in January and would constantly see temperatures of over 100 degrees in the summer.Considering the price, I don’t think that is too bad. The battery was well packed and the box was undamaged. I just thought I’d review this in case anyone was curious as to how well the battery works.

The product fit and after adding the UPS seems to work and short outages do not affect the devices. I have not tested longer times to see how long it lasts - but in general this protects from very short glitches on the power line causing routers, alexa, and computers and related devices to reset.

This battery came out of the box with one of the terminals so corroded that it broke off. Received a refund but just a hassle. The old battery years old had no leakage or corrosion. I would be very concerned that the battery would leak in the item and ruin it. Avoid