If you get the regular male plug battery pack you can get a male to female converter. Yet cyberguys.com for the converter.

Thanks, I should be clear I’m talking about output, not input (so female is the standard in this case)—I’m looking for a product that holds two AA batteries and the current from those batteries is available to other devices via USB. A portable battery pack.

I’ve found dozens of products that do this with 4 AAs—looking for one that holds 2 AAs.