Max consider also adding INA219 voltage and current monitor. You can connect it via i2c bus to most OpenWrt devices, or add additional ESP8266 that will use INA219 chip to monitor current and voltage.

If you don't have some kind of remote monitoring you will regret it later, I talk from experience :)

Also using Grafana is great for this, you can see one of our latest setups:

Cheers,

Valent.