We are now sold on only purchasing YUASA batteries for our UPS's. We have tried cheaper brands 12V 5.5Ah for $9.85 and 12V 6Ah for $15.99 each. Neither can compare to this YUASA! The cheep batteries only will run the UPS on battery for 7 - 9 minutes and they fail in 18 months to 2 years. This YUASA battery will run on the same system and last 14 -16 minutes of run time. Don't know the life of this battery yet, but I am expecting to get 5 years out of them before needing to replacement.