Hi. I recently charged my Bean+ until the amber light disappeared, indicating a full charge. I started a low-power sketch (sleeps a lot) and have been taking voltage readings with a new multimeter approximately every hour. The multimeter indicated the starting voltage was 4.22v. After 24 hours, it is now down to 4.17v.
The question is on the voltage level itself. Everything I have read indicates the Bean+ has no voltage regulator, and that anything above the max value of 3.9V would fry it. However, the built-in LiON battery seems to charge up to 4.22v itself. How is this not a problem for the Bean+ ?