I've switched to using EBL rechargeable CR2s for my Iris v2 motion and contact sensors. (at least for the indoors ones; ones in the garage and outside I still use non-rechargeables)
This has a charger and 8 batteries:
https://www.amazon.com/EBL-Rechargeable-Batteries-Lithium-Battery/dp/B07RGQFBN1
This is just 8 batteries
https://www.amazon.com/EBL-Rechargeable-Batteries-Rangefinder-Boresighter/dp/B07RZRYKGF
