For added convivence, there are voltage selectable battery adapters are available on the market. These units are helpful in situations where the device you are looking to power may be a temporary device, such as a holiday decorative device or if you have multiple devices you wish to power throughout the year, but not used all at ones.

For example, let’s say you have a set of string lights for Halloween which uses 2 AA batteries, and you have a Christmas Light-up Gnome which uses (4) AA batteries. You can use a voltage selectable battery to wall power converter and set the unit to the equivalent input power voltage, in accordance with the chart below.