I'm interested in building a regulated charger for my HTC phone which will work with AA batteries (I'm thinking of using 4 batteries to get good power). However, I want to build a charger that works like the AC charger, that means, one that will charge the phone as fast as the OEM wall charger.
Does anyone have some specs on how these OEM chargers work? I don't think it's the USB port current limiting factor as I've tried with other USB power adapters (for car and AC) with 1A current specs, but they don't charge any faster than the USB port.
If I could get these specs, I will be able to post a simple enough and cheap design to get a reliable charger that guarantees stable current/voltage to the phone.