OK, so I have the previous 450 VA model, but it just failed on me causing a power outage. The battery failed, and power just went out. The next day, the battery bad indicator starting beeping but TOO LATE. For an uninterruptible power supply to cause a power outage is just unacceptable.Everything I have gotten from Belkin has been poorly designed. I replaced with an APC. They seem to have a clue.