I want to purchase an auxiliary battery power unit. Preferably , one that can be powered by AA batteries. Any suggestions?

I have not heard of any such units and I doubt whether they'd be a practical proposition as the iPad consumes quite a lot of current and would quickly exhaust a conventional non-rechargeable alkaline battery - such as the AA style that you mention. There are some external rechargeable units available that have proved popular with Members and these typically double or treble the battery life of the iPad, which is usually more than enough for most people.

Tim

I have a usb one that runs with AA batteries, but yes as stated by Tim that would not really work with ipad, but you can check out this link, would work for what you need. PD110: UltraCharge Portable Power Supply, Portable Power Supply for iPad and iPhone