This Polaroid battery charger does not have a cover. The batteries simply snap into place and the device is then plugged in to start the charging process. A red "charging" light on the front of the Polaroid PDC- 2300Z Battery Charger indicates that charging is taking place. When the charging is completed, a small green "ready" light will begin to glow. The green light will remain glowing until the unit is unplugged.
The Polariod USB Battery charger caught my eye immediately. Wal-Mart had it priced at $9.97. This was the only USB battery charger that they had on the shelf. It is about two dollars less expensive than the next closest charger but it also comes with fewer batteries.