Panasonic vl20 rechargeable button cell lithium 3v 203050mah panasonic vl2020 1hfe this 20mah rechargeable button cell from panasonic is a vanadium pentoxide lithium battery equipped with solder tags offers twice the energy density of button type nickel cadmium battery and ideal for devices such as memory cards pcs phones and video cameras can also be used as a replacement battery for a bmw ignition key panasonic vl2020 1hfe 20mah rechargeable button cell lithium 3v 1 pcs