Esp8266 with backup battery supply

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.

Use a better regulator, there are plenty of low dropout, low consumption, 3.3V regulators.

Thank you. But apart from the regulator is there any other thing you think is wrong with the connection and charging the lipo batteri and using it the same time is there a better way to do that?

I would suggest using the HT7333 regulator, to feed your ESP12, and a ready made charger/protection board to charge the battery, like this one:

https://www.banggood.com/USB-Lithiu...rd-With-Charging-And-Protection-p-924048.html

I have bought those exact parts for doing pretty well what you're doing

You might also consider the Wemos PSU board:

https://www.banggood.com/WeMos-D1-M...rging-And-Battery-Boost-Shield-p-1092773.html

Although this boosts the battery voltage to 5V, which you can then feed to an HT7333 to get the 3.3V.

Thanks. I will try it out