Bit of a long shot but someone may know, Bunnings is currently selling 4.0Ah Einhell (=Ozito) battery packs in a bewildering range of prices, specifically the PXBP-40B (black base) for $49, the PXBP-400 (red base) for $99, and two of them, as the PXBP-800, for ten dollars more at $109. Unfortunately the -800's are out of stock everywhere despite what the web site says and all they've got left are the 40Bs. Does anyone know the difference between the 40B and the 400? I'm assuming higher-current cells or something similar but there's little info out there, and the Einhell web site only shows the -400s.