Zero LiPo EN pin


#1

Hey,

I googled a bit arround, but I don’t find anything about the function of the EN-pin on the board.

When I connect my battery to the GND and VBAT+ pin the Pi boots up, but shows that the battery is low. But it’s fully charged.
Do I have to connect anything to the EN pin to make it work?

Thank you


#2

That strip of header is there for a switch to turn the supply on and off.

You do not need to connect anything to it to make the zero lipo work.

Make sure you are charging the loop correctly and if possible please post a picture of your setup.


#3

Thank you for your answer.
Here a pciture of the setup. It shows the red LED is on, but the battery is fully charged. and the Pi is booting.


#4

You are suppose to use the 2x3 header to solder it onto the pi’s header however you might be able to get it to work that way.

What is the text on the battery?

What voltage is it?


#5

Are you plugging a 6x2 male header right into the breadboard there? It’s hard to tell from the photos, but that will be potentially shorting a whole bunch of pins together!

A @pi2003 suggests, Zero LiPo is designed to sit atop the Pi and not plug into a breadboard like this.


#6

Yes it whould be shorting of the pins, but the zero lipo uses only that pins: https://pinout.xyz/pinout/zero_lipo
So I only connected this to the RaspberryPi. And there is not enough place for the board on the Raspberry, because of the Explorer phat.
I think it does not make a difference and it do work, except of the batterystatus-led. And it is only for testing yet.
The Battery is a 18650 Li-ion with 3.7 V and 3400 mAh, I think it is enough power for testing.


#7

I loathe to say it, but Pinout is incorrect in this case. I’ll have to change that.

Zero LiPo uses 3.3v as a voltage reference fed directly into a comparator (an MCP6001 OpAmp driving the low battery LED) alongside the battery voltage. If you short the 5v output to the 3.3v pins then you will set the voltage reference to 5v, and thus your battery will always read as low.

I don’t believe you will be doing the Zero LiPo any harm. But the low battery LED wont work as designed without a 3.3v reference for comparison.


#8

Thank you very, very much. The problem is solved ;)


#9

You’re welcome. I’ve already pushed a change for the errant 3.3v pin, I’ll get it live :D