Electronic & Hydraulic Shifting (Di2, Ui2, customisations)

Did you actually read the thread though? It's some guy who sells rival kit suggesting Calfee's system is flawed. Let's wait until they start blowing up first...

"The charging circuit could be in the battery pack. That picture looks like a standard power supply. I doubt calfee has the technological acumen to reverse engineer the ultegra signaling while not understanding basic properties of lithium batteries. Stranger things have happened but it's odd to assume they're not doing it correctly from what little information is available."

That's why I said "don't know how true that is mind", the chap who made that comment has worked on a number of WW members bikes, and gets good feedback.

But, yes- of course, he is selling a product that competes, so take what he says with a pinch of salt.