I recently purchased a Quantum MB2 cord that allows the Quantum Battery +1 to power the Canon 580EX II. According to the instructions, you have to place the module that is part of this cord inside the battery compartment of the flash. The cord that attaches to the module is very thick so that the door to the battery compartment on the 580EX II cannot close. Everything works pretty smoothly except that the door to the battery chamber stays wide open. Quantum provides a strip of Velcro that is supposed to tape down the battery door, but I don't see how that can happen without obstructing access to important buttons and the LCD screen on the flash. Quantum also recommeds removing the battery compartment door, but this is easier said than done and might void the warranty . Does anybody have any experience with this configuration and can provide some recomendations. The way I seet it I'm better off with the dedicated battery pack.