We've had many viewers asking if there is a battery operated converter box available. Winegard has come out with a battery pack for their converter. It takes six D batteries. Here is a link for information: http://www.winegard.com/dtv/dig_r.php
Winegard products are available at JK Satellite in Rome, NY
There are also many new battery operated TV's on the market. You can find them at local electronics retailers such as RadioShack & BestBuy. We purchased the Accurian 15-454 at RadioShack to use on remotes where our meterologists need to see their graphics that are on-air. This TV has a bright crisp picture (widescreen so you can watch NBC HD) and reception is great when you're not moving around. We've had varied success while moving. It has rechargeable batteries and comes with a charger, cigarette lighter adapter and a magnetic roof mount antenna for your car. This model is available in the store and there are many models available online.