Would be interesting details to know. I have assembled one of the two I got for Pro and Erik did a good job. It has a switch for On from LiPo or Charge&On from USB.
I just edited my Add-On today to drop from 3 to 2 LiPo's as I'm not sure what to expect for $12. It will have a larger board to work with so It could include Proto Area or other to be more handy - but I'm not sure anything like that was offered.
As I noted on KStart today also I have found Newegg has LiPo equipped USB out battery banks I got (on sale) for $10 and $17 that are 3.2Ah and 13Ah respectively, and the charge system in them with POWER and AUTO charge when connected. The Larger unit does drop power on disconnecting and connecting charge cord to the battery, but the 3.2Ah unit does not. They are the FREEMO Q-02 and P130. Not small with 1 or 4 18650's inside - but compact for what they are with a charge system built in for longer power runs in a system that can hold them. I haven't had long to (ab)Use these units - but so far they are impressive as others I got won't charge and output power at the same time - and some units cut off on LOW POWER draw - these don't do that that I have seen running other things under 50-100mAh.
