Hello, what is the smallest rechargeable battery I can use with the Myoware sensor? Alternatively, using the MyoWare power shield, can I use LIR2032 batteries and recharge them with one of these boards (click on the link)?
LIR2032’s should work and are in parallel on the shield so you should have no issues charging them. Those are 40mAh batteries though and you need a charger designed for a small battery. Using too large a charger may shorten their life or can cause them to explode.