Backup Battery and status LED glowing RED at a very low level (in absence of powersupply)

I have a Photon applications with a CR2032 battery attached to VBAT. When powering the whole thing down while still having the backup battery attached to VBAT, I observe that the status LED is glowing RED at a very low level: you can hardly see but its there and it vanishes as soon as I remove the backupbattery as well.

I know that in one of my earlier experiments with this particular device (an application without a backup battery, btw) I blew up the D0 GPIO as a result of some clumsiness. However the other inputs and outputs seemed to act correctly. So this device seems to work rather normal; the only noticeable thing is the RED glowing when the CR2032 is attached, which still makes me doubt as to whether I should I should use this device or simply throw it away.

Has anybody any advice?

@Jan_dM This sounds like a hardware issue rather than a Firmware Libraries?

I can confirm that a ‘normal/undamaged’ Photon does not have its LED glow dimly red when a coin cell battery is connected between VBAT and GND.

You could dispense with the backup battery and connect VBAT to GND - suggest a reading of the Retained RAM Tutorial by Rick to understand this :wink:

Otherwise if you need backup through powerdown then use eeprom? This might avoid you throwing away the hardware which is 95% operational. FYI - I have a small collection of Photons which had D3 or D4 fried due to lack of ESD protection - they are still useful for prototyping so long as D3/D4 aren’t used.

Thank you for the quick response.
And of course it is hardwarean instead of firmware libraries; I was too quick in issuing my request, without looking accurately at the categories. I appologize for that.