This unit consumes about 300 watt-hours per day (drawing around 45 watts while the compressor's active). That means a 250 amp-hour 12-volt deep cycle battery will keep this arrangement. With the AC/DC option, the Sundanzer can run off AC or DC. The Sundanzer will use DC as a backup, automatically switching to your batteries if the AC goes out . A LED display could tell what the internal temperature is without having to open the unit. While the Sundanzer is not fancy, it is reliable. It's also a very flexible product; you can start off using it just like any other fridge/freezer, running it off standard household AC; no batteries are needed in this configuration. Its ability to handle both 12 and 24 VDC is another testament to its flexibility.