If you don't want to plug into your computer like me (mine is an old compaq) get a USB adapter. I got mine from Wal-mart. It plugs in the wall and I plug the passthru into it.
Make sure it is at least 3 1/2 volts and 1000 mA, Mine says 3 1/2 volts 1300mA or 5 volt USB power. Do not ask me what all that means! Some of the guys on here told me what to get and I did..it works!
I had an auto 901 passthry but it sizzled. They say that's normal and it did work fine, but it made me nervous. I got a manual 901 passthru and it works like a dream! (no sizzle, lots of vapor)
Anything that saves battery wear and tear is worth it's weight in gold!
5 volt for a car adapter! I got one of those too..I sure like it for long drives.