I am working on a portable raspberry pi machine that I want powered by 2 18650 batteries. Since everything in the project runs on 5V, I just want the two 4.2v batteries in parallel with a boost converter stepping it up to 5v and powering all of the devices. I want it to be charged via micro USB and I'm considering two IC's for the charging circuit: The LTC4054 or the BQ2056. Datasheet links at the bottom. Both of these datasheets state that they are single cell, which slightly confuses me. What constitutes as multi-cell: having the cells in series, parallel, or both? If I can't link the batteries in parallel, would I just be able to buy two chips and separately charge each battery?(with a slight change of the current wiring setup, of course)
Thanks in advance,
Tom
Datasheets for LTC4054 and BQ2056:
http://www.linear.com/product/LTC4054-4.2