Hello, everybody Is there anyone who knows where can I buy an external battery for 770? I bought a generic external battery from global-batteries, but it turns out that 770's power supply is special and the external battery can't make 770 work. I guess there's some kind of communication between the AC-4U and 770, so normal external supply won't work at all. I really need an external supply which can independently provide power to my 770. Thanks for any suggestion.
