TP4056 + DW01A + FS8205A LiPo Circuit — OD Stuck LOW Even with Healthy Battery

Other Hardware General Electronics
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Hi everyone,

I’ve built a USB-C LiPo charging circuit based on the classic TP4056 + DW01A + FS8205A combo, inspired by designs from reputable sources and forums. This is a known-good design — I’ve seen it work for others — but for some reason, my board isn’t behaving as expected.

Schematic:

image
image1508×772 137 KB

The setup:

  • USB-C input → 5V regulated from charger
  • TP4056 for charging
  • DW01A + FS8205A for protection
  • 600mAh single-cell LiPo (new and healthy)
  • LEDs on CHRG and STDBY pins via 1.8k resistors

Symptoms:

  • CHRG and STDBY LEDs never turn on
  • OD pin on DW01A is stuck at 0V
  • GATE is stuck HIGH (~3.8V) → FS8205A is OFF
  • So the battery is completely isolated from the rest of the board
  • The TP4056 BAT pin sees 0V → thinks there’s no battery → no charging activity

Tests I’ve done:

With USB-C connected:

  • VBUS: 5V
  • R6/R7 (USB-C CC resistors): Working correctly — one is 1.5V depending on plug orientation
  • LiPo+ measured: 3.8V
  • DW01A VDD and VC: ~3.4V–3.8V
  • OD = 0V
  • GATE = 3.8V
  • TP4056 BAT pin = 0V
  • Tried manually shorting OD to GND (1–2 seconds) to reset DW01A — no effect

Then I replaced the battery with another fully charged 3.8V one — still the exact same behavior.

My understanding:

The DW01A should auto-recover once the battery is above the overdischarge release threshold (3.0V). According to the datasheet, OD should go high and allow current through the FS8205A — but it doesn’t.

I know this combo is sensitive to false overcurrent detection. I’ve checked:

  • No shorts on CS, GATE, or OD pins
  • No visible soldering problems
  • Measured across FS8205A pins 1–4 and confirmed there’s a full Vdrop — FETs are off
  • Cleaned the area with IPA, reflowed FET + DW01A just in case

What I’m wondering now:

  • Am I missing something obvious that prevents DW01A from exiting protection?
  • Could a spike from TP4056 at boot be latching the overcurrent logic?
  • Would adding a pull-down on GATE help?
  • Is it time to just bypass the FETs for testing?
  • Could there be something subtle in layout or trace resistance that's triggering the overcurrent?

Any ideas, tests I should try, or similar experiences would be much appreciated :folded_hands:
Happy to share a schematic or board pics if needed.

Thanks in advance!

2

Somewhere on this forum is an updated schematic. Yes there are additional parts.
I found it. Look at this entire thread, and any linked threads because there is a LOT of valuable and correct info here.
https://forum.arduino.cc/t/at-last-18650-charge-boost-module-with-load-sharing/1164462/5?u=sonofcy

3

I don't understand your circuit. The mosfets are supposed to switch Lipo- to GND, not Lipo+ to VBAT.

I think you need to look at the schematic in the DW01 datasheet again. This is low-side switching to implement protection.

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Note that many of these boards are onfigurated for a high charge rate (1Amp), which is likely too high for a small 600mA cell.
Leo..

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