9-volt.html



Panasonic PP3 (9 volt) battery

A PP3 battery, commonly referred to simply as a "nine-volt battery", is shaped as a rounded rectangular prism and has a nominal output of nine volts. Its nominal dimensions are 48 mm × 25 mm × 15 mm (ANSI standard 1604A). It is widely used in smoke detectors, guitar effect units, pocket radios, radio-controlled vehicle controllers, and as backup batteries for digital clocks and alarm clocks. PP3 actually refers to the type of connection or snap that is on top of the battery . The PP3 connector (snap) consists of two connectors: one smaller circular (male) and one larger, typically either hexagonal or octagonal (female). The connectors on the battery are the same as on the connector itself -- the smaller one connects to the larger one and vice versa.

History

The PP3 appeared when portable transistorized radio receivers became common, and is still called a "transistor" battery by some manufacturers. The Energizer company claims that it introduced this battery type in 1956 [1]. It is very widely used in smoke alarms and carbon monoxide alarms.

Technical specifications

The battery has both the positive and negative terminals on one end. The negative terminal is fashioned into a snap fitting which mechanically and electrically connects to a mating terminal on the power connector. The power connector has a similar snap fitting on its positive terminal which mates to the battery. This makes battery polarization obvious since mechanical connection is only possible in one configuration. The clips on the 9-volt battery can be used to connect several 9-volt batteries in series. One problem with this style of connection is that it is very easy to connect two batteries together in a short circuit, which quickly discharges both batteries, generating heat and possibly a fire. The wiring usually uses black and red wires, red for positive.

Inside a PP3 there are ordinarily six alkaline or carbon-zinc 1.5 volt (nominal) cells arranged in series. These are either AAAA cells, or special flat, rectangular cells. The exact size of the constituent cells varies from brand to brand -- some brands are slightly longer than others -- as does the manner in which they are joined together. Some brands use soldered tabs on the battery, others press foil strips against the ends of the cells.

Very cheap versions may contain only five 1.5 volt cells. Rechargeable NiCd and NiMH batteries have various numbers of 1.2 volt cells. Lithium versions use three 3.2 V cells - there is a rechargeable lithium polymer version.

Lithium 9v/PP3

Lithium "Ultralife" PP3, shown with AA and AAA

The latest innovation of PP3 battery, is the Lithium PP3 (U9VL-J, U9VL-X, U9VL-FP, U9VL-FP, Li9V & ER9V) which is a consumer-replaceable, high energy density battery that can last up to 5 times longer than ordinary alkaline 9-volt batteries and up to 10 times longer than carbon-zinc batteries in many applications. An additional property of the lithium PP3 is its long shelf life, up to 10-years for the aluminum-jacketed U9VL-J battery.

Common applications for this lithium PP3 include smoke and CO (Carbon Monoxide) alarms.

Unconventional Uses

Placing steel wool across the terminals can cause the steel to ignite. This method of fire starting is often taught from a wilderness survival perspective - even wet steel wool can be used (whereas wet matches are useless). This method is also often used by prisoners to light cigarettes^{citation needed}.

See also

• Battery recycling

External links

• A Look Inside a 9 Volt Battery
• What charger should I use?
• Your guide to types of household batteries (AAA, AA, C, D, and 9V)
• Brand Neutral Drawing Of 9 Volt Alkaline Battery based on ANSI Specifications
• Brand Neutral Drawing Of 9 Volt Carbon Zinc Battery based on ANSI Specifications
• Brand Neutral Drawing Of 9 Volt Lithium Battery based on ANSI Specifications
• Brand Neutral Drawing Of 9 Volt Rechargeable Battery based on ANSI Specifications