A 'charging' device typically shorts the two data pins together to identify itself as a dumb power source, but this isn't implemented consistently by different manufacturers (Apple are notorious for doing their own thing in this regard). The obvious alternative is to leave the data lines floating, which some devices will happily charge from, but others won't (because following the standard, they're waiting for a host controller to tell them how much power they can draw), or will only do so at a reduced current. I can't remember which the Edge needs to not go into PC mode.
But it probably doesn't make a lot of difference, as the connector on the E-Werk looks proprietary.