Boost converter voltage breaks down when load is connected

[orangedays22]

I made a PCB that is supposed to charge, protect and boost a lipo battery to power my arduino nano, display and sensors. Also it should offer a voltage divider to measure the charge status with the MCU.

What doesnt work with the boosting: The charging works but the boosting doesnt: If only the battery is connected, the voltage breaks down as soon as a small load is connected. For instance with a 200mA load, it breaks down from 5.2 to 3.6 volts. This also happens if I connect my bench power supply with 4.0V to the battery pins to see if it was the lipo battery that doesnt work. But it is the same problem.

What doesnt work with the protection When I connect my bench power supply to the battery pins and a multimeter to the boost output, it is supposed to shut off over 4.25V and under 2.9V. Well, it doesn't. Both of it. It works on the lower side until 2V (dropout of the boost converter, not the protection IC) and still works with more than 6V (havent tested higher).

The project and PCB (scrematics and the pcb traces) can also be seen here if you click on "open in editor":

zLiPo_V2BESTELLT - EasyEDA open source hardware lab

It would be highly appreciated if someone could help me out here!

[TomGeorge]

@orangedays22

The project and PCB (scrematics and the pcb traces) can also be seen here if you click on "open in editor":

Please post EXPORTED jpg, or pdf images in your post, some platforms used by forum members cannot open or display EasyEDA files.

Did you protoboard or strip board your project before going to PCB?

Thanks... Tom...

[orangedays22]

I'm so sorry, I totally forgot to include the schematic!
Here it is:

I have not protoboarded since the components such as the ICs are so small I can't really manage to deal with them. I usually always do it with sensors and motors, but not with the ultra small SMDs. Also, I would not know what to connect differently even on a prototype. I just can't find the error in the cirquit.