A CR-V3 battery (sometimes CRV3) is a type of disposable high-capacity 3-Volt battery used in various electronic appliances, including some digital cameras. It has the shape and size of two side-by-side AA batteries. This allows CR-V3 batteries to function in many (though not all) devices originally designed for only AA batteries. An RCR-V3 battery is a rechargeable 3.7 V lithium-ion battery.
Read more about CR-V3 Battery: Disposable CR-V3 Batteries, Rechargeable RCR-V3 Batteries