Heltec V3 solar operation

[Basti77]

Hello, I attached my node to the top of a flagpole using a solar cell and 3 lipo cells (parallel). it worked so far so well, only now the weather was bad for a few days and the battery ran out. the strange thing is that the node doesn't come back online after a few days of sun. the batteries should be full again by now. the batteries have a TP-4046 charging module upstream so that they are not overloaded. https://www.hotmcu.com/tp4056-micro-usb-5v-1a-lithium-battery-charger-module-p-145.html the strange thing is that when you disconnect the battery and plug it back in, the node wakes up again.

is there a trick?

[barbabarros]

The TP-4046 is also present in the Heltec v3. I don't know if two TP-4046 (battery + Heltec 3) are good.

(TP4056?)

[Basti77]

After a few days, I realized that the Heltec module was unsuitable for this application and switched to a RAK4631.
It receives much better and the battery somehow never runs out anymore.

[purehunter1]

I have a Heltec Vision Master 190 and it also seems to be unable to run with solar power.
I tried to reproduce the problem with lab power supply. Here it turned out, that the Heltec module relies on a stabilized 5V supply capable to source the required current. If the 5V supply is weak, which is always true for a solar cell at least in bad weather, the Heltec starts to reset randomly, even when the battery is nearly full. The worst is, that it never leaves this reset loop unless the battery is also completely drained while the 5V are completely down.
So I'm asking myself, what this nonsense circuit for a battery should be for, if the 5V supply may not fade. If I saw it right, the problem starts when the 5V 'returns' and raises from zero to a small amount far below 5V.