Transponder/Com portable install w/battery

[DavidBrien]

I am looking to install a Becker transponder and Comm radio in a J3. I was thinking of a small motorcycle deep charging battery to power the units. I think the install would be very easy. My concerns are the modification or 337 paperwork that might be required. Or just having the battery in a Velcro Box and having the equipment Velcro attached so it would not be considered an attachment or permanent install. Any suggestions from a FAA stand point. Our FSDO out here is not friendly to anything or anyone. Anyone have something similar?

 

[jimrice]

 

[d.grimm]

 

[soyAnarchisto]

 

[JimC]

 

[d.grimm]

 

[DavidBrien]

 

[cubdriver2]

 

[N1500N]

 

[yogi63bear]