OP already has been told that there is a 220k:100k voltage divider on a Wemos D1 Mini pro.
Only an extra 100k series resistor is needed to increase measuring range from ~3.2volt to ~4.2volt.
Maybe the analogue input of the WeMos is damaged, maybe the battery is not properly connected to A0.
We won't know until we see a clear picture of the setup.
Leo..