My new phone charges via USB so I gained a generic wall plug charger that accepts a standard A-type USB plug. Huzzah not only can I charge my phone, but also my wireless headset and my PS3 controller without having to leave the PS3 on.
Yeah of course that didn't work.
It charges the phone of course, and my Sony PS3 wireless headset; what it won't charge is the controller. Nothing wrong with the cable, nothing wrong with the controller. Looking around the 'net others have posed the same question and the consensus answer is surprisingly moronic (on Sony's part).
A USB cable has four internal wires - the outer two for power, the inner two for data. My wall socket charger only uses the outer two wires as it has no requirement to share data with my electrical wiring; and I'd be a little Skynet level of worried if it did. This is fine for my phone and headset, but it seems Sony's controllers won't accept a charge unless it can also accept a handshake/connection on the data lines.
Any reason why? Hmm beyond being able to sell special charging stations I can't think of any, but I guess that's enough.
So when it comes to charging it's all Animal Farm - 4 connectors good, 2 connectors bad.