Small battery-operated portable televisions, while valuable in time of disaster, are generally poorly suited to digital conversion. While at least one CECB (Winegard's RCDT09A) is operable from an external battery pack, the combination of television, converter, external antenna, and power supply limits portability. , portable digital LCD TV sets cost at least $100, and could not be used while in motion at significant speeds (restoring this analog functionality would require broadcasters to transmit mobile TV via the separate ATSC-M/H standard, which would in itself require new tuners).