Use the right procedure to change the batteries on your Wetjet, and your Swiffer should last a long time.
Turn the Wetjet mop-side up. Push the white button on the front of the Wetjet panel to release the bottle of cleaner. Remove the bottle and set it aside to avoid leaks while changing the batteries.
Hold down the purple tab below the white bottle-release button and gently swing the battery compartment door open. Remove the compartment from the Wetjet handle.
Remove the four old AA batteries and replace with new ones.
Slip the two tabs at the bottom of the compartment door into the two slots near the bottom of the Wetjet handle. These slots are just above the white plastic hinge that connects the mop head to the handle. Hold down the purple tab at the top of the compartment door and gently swing the door back into place on the Wetjet handle. Release the tab when the door is back in place.
Push the bottle of cleaner back into place. The bottle is secure when you hear it snap into place.