Take radio to shed and connect it to antenna and battery . A service station is a good place to find car batteries. Go inside the cashiers booth. Examine the trashpile inside the cashiers booth and get battery. Look at the battery.
All car batteries have liquid inside.
Fill the battery in the lake. Use the hydrometer. The battery must be charged before it can power the radio. Examine the basement laboratory. There are two items in the lab a mixing vat and a staircase.