Many watches and small wearable devices use CR2032 batteries. Replacing these batteries every few months is not fun. LR2032 batteries can help. They are rechargeable and work like your CR2032 batteries. You can use the Zackees Rechargeable Coin Cell Charger to recharge these small batteries. LR2032 batteries are compatible with the Logitech K750 solar keyboard, TENS therapy systems, and a wide variety of other small gadgets.
The LIR2032 rechargeable cell has a higher operating voltage (4.2v) and is rated at 35-40 mAh. Sets you back under $20 at this time.