Instead of using radios that use electricity and generate waste trough the disposal of batteries use a radio that uses the power of humans as the form of electricity.  There are many items on the market but use tand you'll find a lot of savings while helping out the environment. 

FR300 is ideal for catching the play-by-play in the stands. It can be crank-operated, which means no need for AC power and zero battery waste. The FR300 has a TV audio section and will even recharge a dead cellphone battery in a  pinch.

http://www.amazon.com/gp/product/B000JL8ZFC?ie=UTF8&tag=creatcitiz-20& 

reference link: http://www.amazon.com/gp/product/B000JL8ZFC?ie=UTF8&tag=creatcitiz-20&

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