Low battery reboots on wemos d1 mini

[sasso]

hi

I have a little problem

I'm running a wemos d1 mini of a 5000mAh power bank with 30min deepsleep, all works fine untill the power bank is nerly depleted at witch point the wemos starts to power cycle or reboot, it seems that there is enough power to wake up but at the point when wifi starts to draw more power it shuts down and again restarts.

How can I limit the minimum voltage/capacity/???? to completley disconect the power to prevent constant reboots.
This is my test phase and I would like to run the wemos out of 1/2 AA SAFT Li-SOCl2 battery at the end and I need some kind of circuit to prevent this from happening

sorry for my english but hope to be clere enough for you guys to understand