A little project I thought of:
People have a lot of "smart devices" (aka Phones, etc).
I'm not going to go into the topic of batteries and overcharging. That is a topic unto itself.
But I was thinking.
(This will require special "split" power leads - maybe)
You plug your device into the charger. It charges. If you go past and happen to look and notice it is charged, you unplug it.
With MQTT on the device/s, they could send a message when their battery is full.
Ok, this is kind of off topic for "Node-Red" and more for MQTT. But as I am using NR and it has MQTT, I am just asking.
When the device is plugged in it sends an identification message to the charger and requests power.
Power is supplied until the battery is full when another message is received (by the charger) saying "I'm full".
The state of any plugged in device could be shown on a small display, or a NEOPIXEL LED.