I have 2 Jackery batteries, a 6Ah and a 12Ah. They both work fine with my loaded Stratux, and Jackery batteries support pass-thru charging. They also have a 20,100 2 port 3.4 amp version:

http://www.amazon.com/gp/product/B015QGW4BU/ref=ask_ql_qh_dp_hza

EDIT: I meant to add that it's cheaper, too.