I can already see that the non-proprietary battery pack is going to be both a blessing and a curse for this system. Occasionally, there will be some electronics issues with either the battery pack, wiring, or derailleurs that users (and Ltwoo) are going to have to deal with, but I imagine that much more commonly there will be issues with cheap, garbage cells that fail or are DOA. Savvy troubleshooters may zero in on the root cause quickly enough, but some are going to struggle. I'm no expert on lithium cells, but when I bought mine on Amazon for this setup I was really put off by the number of terrible reviews almost all of the make/model cells had on Amazon in the US. There wasn't a single product that had over 3/5 reviews that had sold more than a dozen units. I opted to go through a site dedicated to selling flashlight batteries, as they at least had some more quality offerings.