The Coolpix L180 uses AA Size battery (Alkaline, NiMH, Oxyride or Lithium).
The Coolpix L810 flash settings cannot be change when shooting in certain scene modes. Example: Landscape, Sports, sunset, firework show, E.T.C. The camera will not respond when you press the flash button. However, you should have full control over the flash setting when shooting in Auto Mode.
Press the scene button on the Coolpix L810 and there should be four icon listed on the left side of the LCD. Scroll down to Auto Mode and press Ok, or reset the camera back to the manufacturer settings by Pressing the Menu button-->Setup Menu-->Reset All.
Note: If Image Mode shows up when you press the menu button, press the left multi selector (self timer button) until you see the wrench tool highlighted in white, and then scoll down and select it.
If the flash does not work while in Auto Mode, You may need to sent the camera in for service. our contact information can be found at support.nikonusa.com