Three years ago, I bought three Back-Ups (2 BE750, 1 BE650). Two protect computers from power surges and power outages. These two also have an electric clock and a cordless phone base-station attached. The third Back-Ups is dedicated of keeping a alarm clock/radio operating through power outages. For surge protection, and for allowing orderly computer shutdowns during a power outage, the Back-Ups perform as desired. However, as an back-up power source for operating the telephone base-station and the alarm clock/radio, they are useless. The units will power themselves off within a short time, even with virtually no power drain on them... such as an electric clock. The batteries in the Back-Ups should be able to keep an electric clock running for months, but the units shut themselves off in less than an hour... much less. That "feature" was not mentioned in the description and features. I would not have purchased them if I knew their limitations. Having three units that do not fully serve my intended use is disappointing, to say the least.