Is it true that one MUST use ONLY the EXACT USB charger that comes
> with their cell phone? Are USB chargers really not interchangable?
> The T-Mobile store told me I could only use their T-Mobile charger for
> my new USB based cellphone. After showing me the charger for the
> Motorola V195 which is 5.9 volts 375ma, they then opened a desk drawer
> and handed me three melted USB chargers, one at 5.0 volts, 750ma;
> another at 5.0 volts, 550 ma, and yet another at 5.2 volts 450 ma.
> Can we swap these supposedly USB chargers or not?
> - Blackberry TCPRIM2ULSSN 5.0vdc 750mA
> - Motorola PSM5037B 5.9vdc 375mA
> - Motorola DCH3-05US-0300 5.0vdc 550mA
> - Motorola FMP5185B 5.2vdc 450mA
> Why is Blackberry USB different than Motorola USB which is different in and
> of itself? Can we swap these USB chargers or must we stick to the charger
> that came with the device?
The problem is that many devices draw more current then the USB spec permits, so unless the device can communicate with the PC to get permission to use more power, the device won't charge.
In order for this to work the device needs to identify it's charger separately from a PC.
Depending on the device design, the chargers may or may not be interchangeable. I'm currently charging my girlfriend's Blackberry on a Motorola USB charger I purchased for my Razr.
One can't make an omelette without breaking eggs, but it's amazing how many eggs one can break without making a decent omelette.