A:
The pirhana 150 and 170 are not meant for portability. Neither units come with a battery or battery case. A good unit for you would either be the humminbird 160 portable or 565 portable. Both of these units come with a 12v battery case and suction cup transducer. Because your already looking at the 150 or 170 i would suggest looking into the 160 portable unit as it is very comparable to both of these units.
Keep your compass facing north