Maximum USB Voltage

[flcaptainbill]

What is the maximum voltage that can be sent to the USB port without damaging the unit?

Thinking of making a supplemental battery for my BB. Normal USB voltage is 5VDC. I have a Cig lighter to USB that puts out 5.2VDC. I have seen USB supplemental batteries that take 4 rechargeable AA batteries and connect them to a USB port. Normal AA batteries start at 1.5VDC but the rechargeable ones are 1.3VDC so if you put 4 of them in series you will have 5.2VDC.

I was going to make one of those but got to thinking about the 123 size batteries that are used in photo and high end flashlights. They operate at 3VDC.

I am wondering if two of these in series (6VDC) would b e too much and damage my Storm or other devices that can be charged/operated from a USB port.

[valorian]

Read this article and see if it answers your question. I'm thinking 6V is going to be too much.

Charging Batteries from USB - Maxim