As others may have posted, I have researched on other forums that the PS3 controller lights may not have to be flashing in order to know that it's charging up properly.
I have a couple of Motorola cell phone chargers I want to test this theory with. Though, I'm afraid that if one of them does work with no lights flashing on and off, will it overcharge the internal battery and cause damage (like exploding)? Being that the controller isn't communicating with anything like the PS3 or a laptop which enables the flashing lights.
I have three controllers that I've bought over the last few years, all of them flash until their done charging. When they are full they stop charging automatically and the lights go out, so you know it's done. Not only does automatic charge cutoff save the battery, it allows you to use the controller plugged in for as long as you like without harm.
If you're gonna charge a PS3 controller with a charger that is not using the USB power standard, then you might make a problem for your controller.