I have checked some behaviour in TP4056 boards (with protection circuit) that i don't like at all. (see schemas at the end)
When you use the TP4056 module with the protección board, you will get a dropout voltaje of 0.4 - 0.7V in the output.
That is because the forward voltage of the reverse diodes of the mosfet of the FS8205A.
- DW01A pin 3 is for overcharge control and is connected to pin 5 in FS8205A
- DW01A pin 1 is for discharge control and is connected to pin 4 in FS8205A Also, overcurrent protection use the DW01A pin 1
The TP4056 already control to protect for overcharge the battery, so what about a bypass between FS8205A's pin 6 or 7 and FS8205A's pin 1 or 8 (see datassheet)
We will loose overcharge protection of DW01A, but we have already the TP4056's one.
We will change over current protection as the Ron of the mosfets of FS8205A that DW01A will see, will be the half, so we will change over current protection from 2.5A to 5A (I think both of them are useless, 2.5A is usually a lot for our projects). You can "repair" it by putting a resistence of 30mOhm or bigger instead of the direct bypass.
With this modification we will get the real battery voltaje in our output only loosing the overcurrent protection (more or less), won't we ?
I hope you understand me, what do you think ?