Hi. From the diagram shown here, I am trying to provide an alternative power supply for my esp-12E using lipo 3.7V battery. But i noticed that after adding the 3.3V regulator to the design my voltage comes down to 2.8 which is not enough supply for my esp12. again i know that the circuit is not a good practice for the lipo battery. Can anyone help me out with a standard way of doing this so that i van use my esp8266 while charging the lipo battery as it is in the mobile phone. Thank you.