I am having problems using the Heltec Wireless Stick Lite on Battery. Works good when I use a USB cable for power (and to download code).
On Battery the device keeps joining over and over then will stop. Operation can be erratic at times. Battery is measured at 3.1 v down to 2.9 v. Using CR123A battery.
Is there a schematic available?
I have been running a couple of Wireless Stick Lite boards on Li-Ion batteries, for months on end, over the last couple of years without any problem, so maybe your CR123A battery just doesn’t have enough oomph.
On the schematic front, there was something funny whereby you could only get a copy of the schematic via your ‘account’—the note on the document I have says “Restricted technical data, please do not disclose without permission !!!”—but maybe someone from Heltec will provide the relevant part of the schematic in response to your request. That part of the schematic, though, just shows both the USB and battery inputs passing through a 3.3V CE6260 regulator. A quick look at the data sheet for that regulator suggests that its dropout voltage is ~3.0V, so you probably are walking a fine line there with your battery.
A team mate got the schematic since he buys the sticks.
I do not run good below 3.0V.