Battery power to Beat Buddy

Forgot the power supply to my Beat Buddy this weekend. Since the jam was an hour away I ended up not being able to use the BB. It really as shame there was no provision for a battery. 9V at 500 mA doesn’t seem to be a whole lot of power requirement.
I wonder if anyone has rigged a battery setup?

Seems like this is a good solution for a portable power supply. Amazon sells them.
[SIZE=6]JOYO JMP-01 Portable Power Supply [/SIZE]

Yep, I rigged a 9 volt battery to mine. Works fine, although wasn’t sure how long the battery would last, so I changed it during each set break.

If a 9v battery delivers 500mAh and if the BeatBuddy pedal draws minimum of 300mAh, then it might last ~90 minutes.