Backup battery
Encyclopedia
A backup battery provides power to a system when the primary source of power is unavailable. Backup batteries range from small single cells to retain clock time and date in computers, up to large battery room
facilities that power uninterruptible power supply
systems for large data centers. Small backup batteries may be primary cells; rechargeable backup batteries are kept charged by the prime power supply.
or valve-regulated lead acid
type. The battery keeps all necessary items running for between 30 minutes and 3 hours. Large aircraft may have a ram air turbine
to provide additional power during engine failures.
. The backup battery prevents the burglar from disabling the alarm by turning off power to the building. Additionally these batteries power the remote cellular phone systems that thwart phone line snipping as well.
s have a backup battery to run the clock
circuit and retain configuration memory while the system is turned off. This is often called the CMOS battery. The original IBM AT, for example, used a small primary lithium battery to retain the clock and configuration memory. Modern systems use either primary or rechargeable batteries. Primary batteries required periodic replacement; rechargeable types often lasted as long as the system they supported.
Backup batteries are used in uninterruptible power supplies, and provide power to the computers they supply for a variable period after a power failure, usually long enough to at least allow the computer to be shut down gracefully. These batteries are often large sealed lead-acid batteries
.
Server-grade disk array controller
s often contain onboard cache
memory, and provide an option for a "backup battery unit" (BBU) to maintain the contents of this cache after power loss. If this battery is present, disk writes can be considered completed when they reach the cache, thus speeding up I/O throughput by not waiting for the hard drive. This operation mode is called "write-back caching".
s. In such networks there are active units on telephone exchange side and on the user side, but nodes between them are all passive in the meaning of electrical power usage. So, if a building (such as an apartment house) loses power, the network continues to function. The user side must have standby power since operating power isn't transferred over data optical line.
) is a battery type that is popular in telecommunications network environments as a reliable backup power source. VRLA batteries are used in the outside plant
at locations such as Controlled Environmental Vaults (CEVs), Electronic Equipment Enclosures (EEEs), and huts, and in uncontrolled structures such as cabinets.
GR-4228, VRLA Battery String Certification Levels Based on Requirements for Safety and Performance, is a new industry-approved set of VRLA requirements that provides a three-level compliance system. The compliance system provides a common framework for evaluating and qualifying various valve-regulated lead-acid battery technologies. The framework intends to alleviate the complexities associated with product introduction and qualification.
For a VRLA, the quality system employed by the manufacturer is an important key to the overall reliability of it. The manufacturing processes, test and inspection procedures, and quality program used by a manufacturer should be adequate to ensure that the final product meets the needs of the end user, the application, and industry-accepted standards and processes (i.e., ANSI
/IEC
, TL9000, and GR-78, Generic Requirements for the Physical Design and Manufacture of Telecommunications Products and Equipment.
Battery room
A battery room is a room in a facility used to house batteries for backup or uninterruptible power systems. Battery rooms are found in telecommunication central offices, and to provide standby power to computing equipment in datacenters...
facilities that power uninterruptible power supply
Uninterruptible power supply
An uninterruptible power supply, also uninterruptible power source, UPS or battery/flywheel backup, is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails...
systems for large data centers. Small backup batteries may be primary cells; rechargeable backup batteries are kept charged by the prime power supply.
Aircraft emergency batteries
Backup batteries in aircraft keep essential instruments and devices running in the event of an engine power failure. Each aircraft has enough power in the backup batteries to facilitate a safe landing. The batteries keeping navigation, ELUs (emergency lighting units), emergency pressure or oxygen systems running at altitude, and radio equipment operational. Larger aircraft have control surfaces that run on these backups as well. Aircraft batteries are either nickel-cadmiumNickel-cadmium battery
The nickel–cadmium battery ' is a type of rechargeable battery using nickel oxide hydroxide and metallic cadmium as electrodes....
or valve-regulated lead acid
VRLA battery
A VRLA battery is a type of low-maintenance lead–acid rechargeable battery. Because of their construction, VRLA batteries do not require regular addition of water to the cells....
type. The battery keeps all necessary items running for between 30 minutes and 3 hours. Large aircraft may have a ram air turbine
Ram air turbine
A ram air turbine is a small turbine that is connected to a hydraulic pump, or electrical generator, installed in an aircraft and used as a power source...
to provide additional power during engine failures.
Burglar alarms
Backup batteries are almost always used in burglar alarmsBurglar alarm
Burglar , alarms are systems designed to detect unauthorized entry into a building or area. They consist of an array of sensors, a control panel and alerting system, and interconnections...
. The backup battery prevents the burglar from disabling the alarm by turning off power to the building. Additionally these batteries power the remote cellular phone systems that thwart phone line snipping as well.
Computers
Modern personal computer motherboardMotherboard
In personal computers, a motherboard is the central printed circuit board in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple...
s have a backup battery to run the clock
Real-time clock
A real-time clock is a computer clock that keeps track of the current time. Although the term often refers to the devices in personal computers, servers and embedded systems, RTCs are present in almost any electronic device which needs to keep accurate time.-Terminology:The term is used to avoid...
circuit and retain configuration memory while the system is turned off. This is often called the CMOS battery. The original IBM AT, for example, used a small primary lithium battery to retain the clock and configuration memory. Modern systems use either primary or rechargeable batteries. Primary batteries required periodic replacement; rechargeable types often lasted as long as the system they supported.
Backup batteries are used in uninterruptible power supplies, and provide power to the computers they supply for a variable period after a power failure, usually long enough to at least allow the computer to be shut down gracefully. These batteries are often large sealed lead-acid batteries
Lead-acid battery
Lead–acid batteries, invented in 1859 by French physicist Gaston Planté, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large...
.
Server-grade disk array controller
Disk array controller
A disk array controller is a device which manages the physical disk drives and presents them to the computer as logical units. It almost always implements hardware RAID, thus it is sometimes referred to as RAID controller. It also often provides additional disk cache.A disk array controller name is...
s often contain onboard cache
Cache
In computer engineering, a cache is a component that transparently stores data so that future requests for that data can be served faster. The data that is stored within a cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere...
memory, and provide an option for a "backup battery unit" (BBU) to maintain the contents of this cache after power loss. If this battery is present, disk writes can be considered completed when they reach the cache, thus speeding up I/O throughput by not waiting for the hard drive. This operation mode is called "write-back caching".
Telephony
A local backup battery unit is necessary in some telephony and combined telephony/data applications built with use of digital passive optical networkPassive optical network
A passive optical network is a point-to-multipoint, fiber to the premises network architecture in which unpowered optical splitters are used to enable a single optical fiber to serve multiple premises, typically 16-128. A PON consists of an optical line terminal at the service provider's central...
s. In such networks there are active units on telephone exchange side and on the user side, but nodes between them are all passive in the meaning of electrical power usage. So, if a building (such as an apartment house) loses power, the network continues to function. The user side must have standby power since operating power isn't transferred over data optical line.
Telecommunications networks and data centers
A valve-regulated lead-acid battery (VRLAVRLA battery
A VRLA battery is a type of low-maintenance lead–acid rechargeable battery. Because of their construction, VRLA batteries do not require regular addition of water to the cells....
) is a battery type that is popular in telecommunications network environments as a reliable backup power source. VRLA batteries are used in the outside plant
Outside plant
In telecommunication, the term outside plant has the following meanings:*In civilian telecommunications, outside plant refers to all of the physical cabling and supporting infrastructure , and any associated hardware located between a demarcation point in a switching facility and a demarcation...
at locations such as Controlled Environmental Vaults (CEVs), Electronic Equipment Enclosures (EEEs), and huts, and in uncontrolled structures such as cabinets.
GR-4228, VRLA Battery String Certification Levels Based on Requirements for Safety and Performance, is a new industry-approved set of VRLA requirements that provides a three-level compliance system. The compliance system provides a common framework for evaluating and qualifying various valve-regulated lead-acid battery technologies. The framework intends to alleviate the complexities associated with product introduction and qualification.
For a VRLA, the quality system employed by the manufacturer is an important key to the overall reliability of it. The manufacturing processes, test and inspection procedures, and quality program used by a manufacturer should be adequate to ensure that the final product meets the needs of the end user, the application, and industry-accepted standards and processes (i.e., ANSI
Ansi
Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....
/IEC
IEC
-Organisations:* Independent Electoral Commission * Independent Electrical Contractors, a U.S. national trade association.* Institut d'Estudis Catalans , a Catalan academic institution....
, TL9000, and GR-78, Generic Requirements for the Physical Design and Manufacture of Telecommunications Products and Equipment.