Hi All,

I'm troubleshooting power issues on a device and have narrowed the issue down to this Power-Latch circuit (I think). Proper functioning should be:

-Toggle switch activates Mosfet (unifying grounds) and sends PWR_BUTTON signal to the ESP32 microcontroller.

-ESP32 then maintains a High PWR_HOLD voltage to keep the Mosfet enabled and grounds unified.

The issue is that the Q5 transistor is not fully activated with the 3.2V PWR_HOLD coming from the ESP32. And the Mosfet is not active -> Hence RPP- (battery ground) is not connected to the circuit, causing issues with charging circuit and spooky happenings elsewhere, eg auto power ON on external power input.

Full battery is at 8.2V - Low is around 6.8V

Ground is 0.7A higher than RPP-

The charging circuit is controlled by a BQ24005 connected to ground

How can I saturate these two components Q5 and Q1 to fully activate them?

Please let me know if more info is needed. And if you have a better idea/design for this function, please let me know.

Needless to say I am an amateur/student and may not know what I'm talking about

 

Just to correct and add:
SW1 is a Button not a switch.
ESP32 sends a PWR_Hold Low to Q5, that turns off the device.
This is the entry point of RPP- to the circuit.
Below is the Reverse Polarity circuit showing the entry point of Battery-

 

Just to correct and add:
SW1 is a Button not a switch.
ESP32 sends a PWR_Hold Low to Q5, that turns off the device.
This is the entry point of RPP- to the circuit.
Below is the Reverse Polarity circuit showing the entry point of Battery-

You would need to provide more information, especially showing how the ESP32 is connected with reference to gnd and the complete circuit showing the latch and protection part connected together and to the battery. There appears to be no current limiting resistor to the base of Q5. Q1 appears to have drain and source swapped, but not sure. If S1 is being held down prior to latching then sending a signal to Q5 will make no difference as Q5's emitter is being pulled high via D3. Suggest a 10K for R26 for test purposes.