Is it safe to power the electron with 3 AAA batteries connected through the JST that normally the LiPo battery connects to?
My SoC (fuel) is showing 162.046875. That seems high and I’m concerned about damaging something.
@davewise, it is anything BUT safe. You are connecting a non-rechargeable battery which outputs 4.5 volts into a socket designed for a 3.7 volt LiPo which charges at a maximum voltage of 4.2 volts. I suggest you disconnect your batteries ASAP.
2 Likes
I've unplugged (for now 
) but this post suggests that 4.5 volts is max voltage:
If 4.5 is ok. Any other reason not to plug in to the JST if I don't have the usb power connected? Also, is there a better way to connect the 3xAAA battery pack?
The LiPo battery has an over current, under & over voltage safety switch circuit built into it to prevent over discharge and short circuit conditions.
The AA battery pack could be charged if you supply power to the Electron via USB or VIN pins and your batteries should not be recharged so that could cause some issues if you do accidentally try to charge them.
There is no low voltage disconnect on your AA pack so it’s possible the Electron will drain them down to zero volts and possibly damage the Electron as has happened to others in the past but that’s not guaranteed.
I’m not sure if a diode on the AA pack + line would prevent the pack from being charged or not but that could be a solution to prevent charging the AA cells.
Am I best off connecting via the VIN pins? Can I avoid the accidental charge issues that way?
Also, could I monitor the voltage in the firmware to shut down if there is low voltage?
Yes
You could use a voltage divider connected to an analog input to measure the Vin voltage so that when it is almost at the Photon's onboard regulator cut-off voltage, you can shut down (deep sleep) then.