A
nine-volt battery, also called a
PP3 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.
9V batteries are commonly used in pocket transistor radios, smoke detectors, carbon monoxide alarms, guitar effect units, and radio-controlled vehicle controllers. They are also used as backup power to keep the time in digital clocks and alarm clocks.
Connectors
The 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
Eveready company claims that it introduced this battery type in 1956.
Technical specifications
cells, which are commonly used in medical equipment.]]
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. Multiple 9 volt batteries can be snapped together in series to create higher voltage.
Inside a PP3 there are six cells, either cylindrical alkaline or flat carbon-zinc type, connected in series. Some brands use welded tabs internally to attach to the cells, others press foil strips against the ends of the 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. There is also a Hybrid NiMH version that has a very low self- discharge rate (85% of capacity after 1 year of storage).
Formerly, mercury batteries were made in this size. They had higher capacity than carbon-zinc types, a nominal voltage of 8.4 volts, and very stable voltage output. Once used in photographic and measuring instruments or long-life applications, they are now unavailable due to environmental restrictions.
Self discharge
An alkaline battery that is unused or used with extremely low power consumption devices (transistor leak current, etc.) can be expected to last approximately for 6 years, essentially the shelf-life of a new battery.
Lithium 9V/PP3
and
AAA ]]
The
Lithium PP3 (U9VL-J, U9VL-X, U9VL-FP, U9VL-FP, Li9V & ER9V), 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.
Other nine volt batteries
There are other nine volt batteries, such as PP7 and PP9. These date from the days of early
transistor radios and are now less common than PP3. In the days of
valve radios which used
batteries designed specifically for vacuum tubes, there was a nine volt
grid bias battery which had tappings for various voltages between 1.5 and 9.
See also
Battery nomenclature
Battery recycling
References
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
Category:Battery shapes
