I was using am OEM charger with an extended length USB cable (15') for months without issue, then suddenly my Bionic would not charge past 85% (I could see the charging graph level off in System Panel. Switching to an AC extension chord and a 6' USB cable fixed the problem.
I understand that losses on the longer cable affected charging, but I don't understand how it became an issue after a period of satisfactory use.
The problem I see with Motorola's "ecomoto" chargers is that the included USB cable is only about 24" long, making it very difficult to stick with the OEM charger.