Get an insulated minnow bucket, forget the battery powered bubbler. Buy a 110 volt inverter that plugs into your lighter plug, and a cheap aquarium pump. It will kast forever and pump twice as much air. With no batteries to buy get a few gallons of spring water or untreated well water like I have at home to change the water a couple times a day. Pick out the dead ones and keep water cold with ice or ice packs like a student uses in his lunch box. I can keep minnows in my 5 gallon insulated bucket for days!!