BATTERY [Alkaline]: AAA, AA, C, D, 9-Volt

BATTERY [Alkaline]: AAA, AA, C, D, 9V

• Alkaline battery of various sizes.

(Wikipedia excerpt: ..."An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections[1] for powering electrical devices. When ...supplying power, its positive terminal is the cathode and its negative terminal is the anode.[2] The terminal marked negative is the source of electrons. When .... connected to an external electric load, those negatively charged electrons flow through the circuit and reach to the positive terminal, thus cause a redox reaction by attracting positively charged ions, cations.

Thus converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell.[3]

Primary (single-use or "disposable") batteries are used once and discarded, as the electrode materials are irreversibly changed during discharge; a common example is the alkaline type used for flashlights and a multitude of portable electronic devices. Secondary (rechargeable) batteries can be discharged and recharged multiple times using an applied electric current; the original composition of the electrodes can be restored by reverse current. Examples include the lead–acid batteries used in vehicles and lithium-ion batteries used for portable electronics such as laptops and mobile phones.