TTGO battery discharge protection, does it work?

[MjkCurious]

I bought a Wemos® TTGO WiFi + Bluetooth Battery ESP32 0.96 Inch OLED Development Tool from Banggood. It claims to have over discharge protection for the battery. But when I remove the battery and connect a bench supply to the battery terminals, the unit keeps working right down to about 2.7V. I was expecting it to cut out when I dial the bench supply voltage below 3.0V.

As far as I can tell, the unit uses the battery to boost up to about 5V, then uses a regulator to supply the esp32 with 3.3V. The boost circuit doesn't seem to have any check whether the battery voltage has fallen below 3.0V.

Has anyone else used one of these, or is familiar with typical design? I guess I could use a battery with on-board protection, but I just wondered if I've overlooked something here.

By and large, I'm quite happy with the unit.

[Pibbotley]

I have similar. 2.7V is as design for the onboard TP5410 chip. My problem is charging stopping too soon at <4.1V. Works best with genuine 18650s, avoid the widespread fakes.