I have designed this power supply unit to get 3.3, 5, 8 and 12V. So that it acts like a secondry supply to test and power small projects and mircocontroller.
1) I used TP5100 as charging in 2S mode
2) 5v boost up mt3608 charging to charge the battery direclty from usb_5v
3) Then some linear regulators for 3.3 and 5v
4) And again a mt3608 booster for 12V out
I may utilize same booster circuit for charging the battery and 12V but then I have to change the jumpers and all, which I don't want. I have posted the schematics in a another post similar to this one.