The cable provided with my Astro Anker Mini 3000 doesn't work with or charge my Nexus 7.
I was able to charge the N7 when I used the cable the came with the N7+AAM3000.
I was quite surprised, as the cable provided with the AAM3000 fits the N7 perfectly. The cable works as expected for charging the AAM3000 though. Strange.
As regards the AAM3000 itself, I would be without it. It's brilliant device and very wall made.
After charging, it has recharged 2x Sony mp3 walkmans fully, and part charged my Nexus 7 too.