To replace a Swiffer Sweepervac battery, open the Swiffer Sweepervac's central cavity, and replace the old battery with a new one. Depending on the model you have, you may require a 5-cell or a 6-cell battery.
Place the Swiffer Sweepervac on a table, with its back facing you and its handle extending out toward your right side. Using a flat-head or a Philips-head screwdriver, press the handle release button. Remove the handle, and set it aside. Push the peanut-shaped button above the filter reservoir, open the reservoir door, and remove the filter and any trash.
Cut the product information seal that is affixed to the back of the Swiffer Sweepervac. With the Philips-head screwdriver, remove the screws located along the Swiffer Sweepervac's body. Gently pry the Sweepervac's hemispheres apart with your flat-head screwdriver.
The entire Sweepervac is anchored around the filter reservoir button, which falls off when you separate the hemispheres. Gingerly pull the series of wires that anchor the battery pack to the inside of the Sweepervac. Unscrew the two anchor screws located on either side of the battery pack.
With a spudger, apply pressure to the locks on the red and black wire attachment. Remove the white mount or silver battery caps, depending on your Swiffervac. Remove any protective tape from the new battery pack, insert it into the Swiffervac, and reconnect the wire attachments.