Just wanted to say that everything in this article about the MCU, capacitors and diodes is spot on. (I don't do work with coin cell batteries, but I do have ex

Just wanted to say that everything in this article about the MCU, capacitors and diodes is spot on. (I don't do work with coin cell batteries, but I do have experience with using very small rechargeables and very small solar panels.) To add to it, don't use zener diodes for over-voltage protection. They are extremely leaky. And if you need high value MLCC capacitors you are better off making them yourself from a stack of (more common) 10uF ceramic caps.