Not all flashlights are created equally; likewise, the methods to change the batteries vary from model to model. No matter what, the process usually involves twisting one part of the flashlight to take it apart and gain access to the battery chamber.
Maglite flashlight models, including the Solitaire, feature a twist-off tail cap that holds the batteries in place.
Turn the tail cap counterclockwise until it pulls away from the flashlight. If the flashlight already contains a battery, it may fall out into your hand.
Insert a new battery so the top or pointed end faces the light. The Solitaire requires one AAA battery; other versions may require larger or more batteries, as noted on the flashlight packaging. Note the width and length of the battery chamber as clues to what the flashlight requires if you do not have the packaging, or visit the Maglite website.
Replace the tail cap by turning it clockwise until it stops moving.
Rotate the top portion of the Maglite flashlight left and right until the shining light offers the desired amount of focus. Some Maglite models including those with rechargeable batteries offer a push-button switch to turn the light on. Rotate the heads on such models to focus the beam, as with other Maglites.
Pelican L1 1930 and Element K2 Flashlights
The L1 1930 model requires four LR44 1.5V alkaline coin cells, also known as watch batteries. The Element K2 uses 3 AAA batteries. Both have separate removable chambers that hold the batteries in place; slide the chamber back into the flashlight body once you fill the chamber with the required batteries.
Unscrew the portion of the flashlight nearest the light or lens by turning it counterclockwise until it separates from the flashlight body.
Remove the battery tray assembly after making a mental note of how it aligns in the flashlight body.
Line up the four LR44 cells in the Pelican tray so the positive ends -- the side with a "+" on them -- all face the same way, following the decal diagram on the battery tray. For the Element K2 model, use 3 AAA batteries instead of the coin cells.
Place the battery tray back in the flashlight so it lines up exactly as it was before you removed it.
Twist the top of the flashlight back into place until it stops turning. Press the rubber-coated push switch on the bottom of the flashlight to turn it on.