A CR-V3 battery is a type of disposable high-capacity 3-Volt battery used in various electronic appliances, including some digital camera

Digital camera

A digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. It is the main device used in the field of digital photography...

s. It has the shape and size of two side-by-side AA batteries

AA battery

An AA battery is a standard size of battery. Batteries of this size are the most commonly used type of in portable electronic devices. An AA battery is composed of a single electrochemical cell...

. This allows CR-V3 batteries to function in many (though not all) devices originally designed only for AA batteries. An RCR-V3 battery is a rechargeable 3.7 V

Volt

The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...

 lithium-ion battery.

Disposable CR-V3 batteries

Often, a CR-V3 battery is a single cell based on a non-rechargeable lithium battery

Lithium battery

Lithium batteries are disposable batteries that have lithium metal or lithium compounds as an anode. Depending on the design and chemical compounds used, lithium cells can produce voltages from 1.5 V to about 3.7 V, over twice the voltage of an ordinary zinc–carbon battery or alkaline battery...

 chemistry, with a nominal voltage of 3 V

Volt

The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...

 (the same as 2 alkaline AA batteries). Because both lithium and lithium-ion chemistries offer higher energy density

Energy density

Energy density is a term used for the amount of energy stored in a given system or region of space per unit volume. Often only the useful or extractable energy is quantified, which is to say that chemically inaccessible energy such as rest mass energy is ignored...

 than alkaline batteries

Alkaline battery

Alkaline batteries are a type of primary batteries dependent upon the reaction between zinc and manganese dioxide . A rechargeable alkaline battery allows reuse of specially designed cells....

 or even NiMH

NIMH

NIMH or NiMH may refer to:*Nickel-metal hydride battery, a type of rechargeable battery*National Institute of Mental Health, a part of the United States National Institutes of Health...

 rechargeable batteries, a CR-V3 battery is designed to last much longer than a pair of AA batteries.

Rechargeable RCR-V3 batteries

Rechargeable lithium-ion RCR-V3 batteries, with a nominal voltage of 3.7 V, are also available. A review by Andrzej Wrotniak concluded that "1700 mAh NiMH's easily outperformed [1200 mAh RCR-V3's]" in tests using two digital cameras.