I'm going to be using a lithium manganese dioxide or lithium manganese silicon coin cell battery such as this one but I can't find any information on charging them. Everything I find, both theoretical and breakout boards, talk about lithium polymer or lithium ion. Will these work the same? I assume not. Can someone point me to some resources or charging boards please?
On a related note, is it safe to charge with the battery connected to the circuit? This will be powering a nRF52832 based board the RedBear Nano V2 in particular. Do I need a decoupling circuit of some kind? I'm working with some very tight space constraints so any components I can avoid would be preferable.
You need to study the theory of LiMa battery charging. It's quite different from LiPo theory.
You use button cells? Do they have the needed capacity? Not AA or AAA sized cells?