Sorry dude was disc golfing! When it said 082 that could have been battery percentage, you toggle between percentage and voltage with the button, you need to be on the voltage setting to go up and down. Good Luck, let me know! That pup needs energy!
The batteries go in the back, you'll need to remove two screws. The single button turns it on/off, and it can adjust the voltage up and down by .5V increments. You will hold the button to toggle between up and down. Holding longer shuts it down.