APC UPS Battery Replacement, RBC21, for APC Back-UPS Model BF400C

Battery received quickly and installation is really quick and easy. HOWEVER, be aware that while APC mentions inclusion of of free, environmentally sound, disposal method for old battery this consists solely of a few written instructions re: how to take to your local community disposal site in the same package in which the new battery was delivered to you. So it provides no advantage over buying cheaper, non APC replacement battery. IS THERE A DIFFERENCE IN BATTERY LIFE OVER OTHER BRANDS? Only time will tell.

This is a replacement battery for my UPS. Works very well. One thing that I did not know is that it came with a shipping box and an UPS label for return of defective battery. I liked that idea very much because I was wondering what to do with the old battery.May 2015: bumped up the review because it is almost 5 years and it is still working. Have not stressed test to see how much capacity it still has, but know my model of UPS will not work with a bad battery.

I received a different brand and amps (5.1 not 5.5 as mentioned in the description), but otherwise it's working fine.Be aware substitution likely upon ordering.

The battery on my APC UPS was failing setting off an annoying alarm every so often. I removed the batttery cover and ID'd the part #. Searched and located this brand. Replaced in 30 seconds and all is well. I expect this battery will be good for 3-4 years.

I purchased this battery on August 14, 2011. As of November 24, 2011, it needs replaced - less than 3 months usage.

After 1 month the alarm beeps every day. Very disappointed. I use many APC products but this one failed me.

I saved about $20 buying this item through Amazon. It's exactly the battery my computer needed to restore its backup system.

Good services Excelent