I am looking into the feasibility of taking the HD500 out for busking type gigs. Obviously I will need a power source for my HD500, but those are not always readily available. I was thinking I could purchase a battery pack to take with me, but I know essentially nothing about what kind of amperage I need, or wattage, or voltage, or whatever the limiting factor is (hey, you remember that time I said I knew essentially nothing?).
How hefty a battery would I need to purchase, and how long would you figure a charge could last? If these are extremely stupid questions, I would very much appreciate it if someone would explain it to me like I'm 5.