On a pure DC battery or on a battery run UPS?
The X10 modules all need AC as they send
their signals when the AC waveform is
crossing the zero point in the cycle. So DC
is not possible. On an UPS it is also
questionable. Most use a modified square
wave that the power supplies in the modules
don't like . I have read of some off grid
power users frying modules with the modified
wave from an inverter.