I'm creating a project that goes on the user's wrist, and I'm wondering what kind of battery supply I should use. It needs to be really small. I tried 2 CR2016 3V batteries, it was enough for the arduino to power and run code, but it wasn't enough for everything to function properly. I'm nervous about using Lipo Batteries because they are dangerous and can explode. Any suggestions for a small and safe battery supply?
If current was insufficient maybe try the bigger CR2032 batteries. Or other type of coin batteries. If voltage was insufficient (e.g. if some of the peripherals needed 5V) try adding level shifter.
What is the consumption of the whole hardware setup? Are you going to swap CRxxxx batteries constantly? While Li-Po have downsides they also allow recharging.