I'm charging my NyKo Power Grips...and have been for 5 hours and the red light is still on. How long do these things take to charge (and the light to turn green)??

Also, when using, well...how do you use them?

If they're plugged into the Vita, then you use the Power Grips battery. Once the red light starts to flash the battery is getting low, but then do you let the Power Grips die so that the Vita battery is now being used or what?