I was a little afraid that it might not work, but it was perfect. The previous battery was about 4 years old. Replacing the battery cost less than half of buying a new unit and I was so glad I went this way.
I replaced two of these batteries. One is working OK and other keeps interupting its power output and resetting the PC. I can only use it as a surge protector and not battery back up.
I have been using APC battery back up power units for years. We have power pops here at least once a month. Until I started using the APC protection I had to replace several hard drives, printers, monitors and motherboards due to them being hit by the power off and on. Sometimes it would do it 3 or 4 times in a row killing my eletronics big time. The APC has saved me not only money to replace these things but also the loss of important data time and back aches. I am 71 and crawling around under the desk gets to me these days. I would recmmend this product in a heart beat.
I followed the instructions enclosed with the replacement battery, but the battery alarm keeps going off telling me to replace the battery. I am assuming the unit itself is bad. I recommend you buy a completely new unit and not just a replacement battery. Perhaps buying a replacement battery is better with the more expensive UPC systems. With this version, it isn't worth it. Just replace the whole thing!
Unfortunately the new replacement battery failed after 3 weeks of use and now behaves as if it is an old battery that needs to be replaced. I had to buy a new one from the local store since this was purchased specifically for a scheduled I.T. event with new equipment for server accessory equipment back-ups. I am too busy with my work load to attempt to resolve this with APC online for a refund and basically resolved my situation by resorting to purchasing a new APC back-ups locally from another vendor. I realize time has transpired in posting this review since the unit was ordered and failed but the outcome remained one I thought should be shared. I will only purchase new APC units go forward.