Just a small reminder that waste can also contain valuable resources. For example electronic cigarettes (ELFBAR, etc…) for one time use contain a huge battery which is rechargeable. I found plenty around my home in the city forest. Few of them were heavily degraded, but most of them still worked fine.
Teardown of an original unit – fake units require a little more violence to open up.
Some details how to make use of it (talking about the battery):
500 – 850 mAh is quite nice (smartphones come with around 4000 mAh)
Voltage: as usual 3.3 up to 3.7 Volts
Charging voltage: 4.2 Volts
But for safe use, it lacks a charger board and a protection circuit.
Some example for a charger board can be found with names like “TP4056” or “TC4056A“. To use it as a standard battery, BMS S1 (something like “battery management system”) is helpful aswell.
A few ideas how the battery can be used:
* ESP8266 battery shield
* LED lights