Why I can't start Blade without battery using USB?

[Guest lol looool]

Oo

Uhmmm... you do need the battery to boot the phone... how else can you get it to power on? :)

To clarify - you can take out battery - plug in usb cable and the phone is powered.

Un plug the usb cable, no battery - no power....

That is the question. I can't boot my phone if the battery isn't plugged in. :(

Can it be fixed? Does it happens on another Android phones?

Edited September 8, 2011 by lol looool

[Guest t0mm13b]

Oo

Uhmmm... you do need the battery to boot the phone... how else can you get it to power on? :)

To clarify - you can take out battery - plug in usb cable and the phone is powered.

Un plug the usb cable, no battery - no power....

Edited September 8, 2011 by t0mm13b

[Guest lol looool]

¡

To clarify - you can take out battery - plug in usb cable and the phone is powered.

But Why i can't boot using USB as power source?

[Guest Roph]

A USB 2 host controller can provide at maximum 500mA of current. In real world usage you will almost always get lower, such as if you had your phone and a webcam plugged into 2 USB ports, both going back to that host.

Secondly, in order to correctly receive higher current, the phone would have to negotiate with the controller to enter high-power mode, which would require some initial current in the first place.

When idle your phone will use less than 500mA, but under heavy use, its current requirements can easily increase over what USB is able to provide. I assume that booting is such a requirement. When charging over USB and stressing your phone, it's possible to still actually have the battery charge decrease.

Secondly, the phone isn't wired that way. The power always comes from the battery. When you connect it to charge, the power goes to the charging circuit and onto the battery.

Edited September 9, 2011 by Roph