Why do some BlackBerry devices need Desktop Manager installed (or the driver) to charge?
Posted on 2009-02-11
In order to get a Blackberry device to charge via USB it requires Blackberry Desktop manager or the driver files (RimUsb.sys and RimUsbNT.inf) to be installed on the PC. I did some research on why BlackBerry devices need a driver to charge and I came across some answers:
A1. "4.x (OS level) BlackBerry handhelds require 500mA to charge. You need to have the BlackBerry device driver (for windows) installed natively for this to work. I dont fully understand what the drivers do, but I think they detect the blackberry and *force* the port to output the full 500ma"
A2. "I could not work out for the life of me how the 2 drivers triggered the PC USB port to charge the Blackberry until now. They trigger a "turn on" supply to pin 2 of the USB cable which the Blackberry Unit sees and turns on its on board charging circuit."
It seems logical to me that a boost in current from the default 100mA to 500mA would speed up the charging process.
Q1. Are both answers 1 & 2 correct?
Q2. What is the difference between the A/C>BlackBerry charger and the PC USB>BlackBerry in terms or charging the BlackBerry device? (I know current would be one of them).