The nine-volt battery, or 9-volt battery, is an electric battery that supplies a nominal voltage of 9 volts. Actual voltage measures 7.2 to 9.6 volts, depending on battery chemistry. Batteries of various sizes and capacities are manufactured; a very common size is known as PP3, introduced for early transistor radios. The PP3. Historically, the now-popular PP3 battery size was a member of the (PP) battery family that was originally manufactured by in the United Kingdom and in the United States. The company. Very often, a "9-volt" battery refers to the transistor radio size called PP3 or IEC 6F22 or NEDA 1604, although there are less common nine-volt batteries of different sizes. Batteries of all types are manufactured in consumer and industrial. Lithium 9-volt batteries are disposable high-energy-density batteries. In the PP3 size they are typically rated at 0.8–1.2 Ah (e.g. >1.2 Ah @ 900 ohms to 5.4 V @ 23 °C for one type), about twice the capacity of alkaline batteries. Some manufacturers claim the • Media related to at Wikimedia Commons The PP3 battery has both in a snap connector on one end. The smaller circular (male) terminal is positive, and the larger hexagonal or octagonal (female) terminal is the negative contact. The connectors on the battery are the same as on the load device; the. are devices that charge batteries, some of which may also be able to charge nine-volt batteries. Whether a charger can charge the battery depends largely on the dimensions of the battery and internal chemistry (I.E., disposable batteries cannot be. • • • • •.