Disabling battery on Adafruit Huzzah still drains power

Using Arduino Microcontrollers
#1

Hi,

I hope that this is the right place to ask this question:
I am using the Adafruit Huzzah for a project and hooked a LiPo battery to the on board JST connector. To disable the battery when I turn off my application I am pulling the EN pin down to GND via a switch.

So far so good.

I have now observed, that the battery is drained far more than expected after a few days without using and charging my system and I am wondering why. I understand, that the EN pin is tied to a pull up resistor and as a result will slowly discharge the battery over time (when not connected to USB).

But when I measured the current it was around 7mA, which is unacceptable for supposedly disabling the battery.

Here is the schematic:

1545×1065 27.4 KB

And here more info about the power management on the board:

I don’t know if the battery charger IC or the voltage regulator allow a small current or if there is something entirely else that I am not seeing.
Does anyone have an idea?

Cheers,
Nik

#2

Hi Nik,

I'm not sure if this Adafruit forum thread answers your question?: Adafruit customer service forums • View topic - Battery drain when EN pin is grounded.

In summary it turns out that the earlier revision C Huzzah Feather ESP8266 boards have virtually 0mA current consumption when the enable pin is pulled to ground, whereas the later revision E boards drain around 6mA. It's possible to determine the board revision from the silkscreened circled letter under the USB connector.

#3

Yes, that seems to be it.

Thank you, I'll check out that thread.

#4