other ddesigns of battrries

   

Hybrid topology / double conversion on demand

These hybrid designs do not have an official designation, although one name used by HP and Eaton is double conversion on demand. This style of UPS is targeted towards high efficiency applications while still maintaining the features and protection level offered by double conversion.

A hybrid (double conversion on demand) UPS operates as an off-line/standby UPS when power conditions are within a certain preset window. This allows the UPS to achieve very high efficiency ratings. When the power conditions fluctuate outside of the predefined windows, the UPS switches to online/double conversion operation. In double conversion mode the UPS can adjust for voltage variations without having to use battery power, can filter out line noise and control frequency. Examples of this hybrid/double conversion on demand UPS design are the HP R8000, HP R12000, HP RP12000/3 and the Eaton BladeUPS.

Ferro-resonant

Ferro-resonant units operate in the same way as a standby UPS unit; however, they are online with the exception that a ferro-resonant transformer is used to filter the output. This transformer is designed to hold energy long enough to cover the time between switching from line power to battery power and effectively eliminates the transfer time. Many ferro-resonant UPSs are 82–88% efficient (AC/DC-AC) and offer excellent isolation.

The transformer has three windings, one for ordinary mains power, the second for rectified battery power, and the third for output AC power to the load.

This once was the dominant type of UPS and is limited to around the 150 kVA range. These units are still mainly used in some industrial settings (oil and gas, petrochemical, chemical, utility, and heavy industry markets) due to the robust nature of the UPS. Many ferro-resonant UPSs utilizing controlled ferro technology may not interact with power-factor-correcting equipment.

DC power

A UPS designed for powering DC equipment is very similar to an online UPS, except that it does not need an output inverter. Also, if the UPS's battery voltage is matched with the voltage the device needs, the device's power supply won't be needed either. Since one or more power conversion steps are eliminated, this increases efficiency and run time.

Many systems used in telecommunications use 48 VDC power, because it has less restrictive safety regulations, such as being installed in conduit and junction boxes. DC has typically been the dominant power source for telecommunications, and AC has typically been the dominant source for computers and servers.

There has been much experimentation with 48 VDC power for computer servers, in the hope of reducing the likelihood of failure and the cost of equipment. However, to supply the same amount of power, the current would be higher than an equivalent 115 V or 230 V circuit; greater current requires larger conductors, or more energy lost as heat.

Most PCs can be powered with 325 VDC. This is because most ATX switching power supplies convert the AC input voltage to approximately 325 VDC (230 × √2). On units with a voltage selector switch, the 115 V setting enables a voltage doubler that puts the top half of the AC wave in one capacitor, and the bottom half in the other capacitor. This mode uses half of the bridge rectifier and runs twice as much current through it. The 230 V setting simply rectifies the AC using the full bridge rectifier, and puts the it into both capacitors. These two capacitors are hardwired in series.These power supplies can almost always be safely run on 280-340 VDC long as the selector is in the 230 V position. They will not work at all with DC power in the 115 V position; with 162 VDC applied, nothing will happen because only one capacitor is being charged; if 325 V is applied, you will blow the fuse and a surge suppressor or capacitor. Power supplies with Active-PFC are usually Auto-ranging and have no voltage selector switch. They usually have one input capacitor, it is charged to 320-400 VDC by a boost-mode power supply that is part of the PFC circuit. It is uncertain how various Auto-ranging and Active-PFC power supplies will respond to having DC power applied when they are expecting AC 50–60 Hz power. A laptop computer is a classic example of a PC with a DC UPS built in.

High voltage DC (380 V) is finding use in some data center applications, and allows for small power conductors, but is subject to the more complex electrical code rules for safe containment of high voltages.

Technologies in ups

     
     The general categories of modern UPS systems are on-line, line-interactive or standby. An on-line UPS uses a "double conversion" method of accepting AC input, rectifying to DC for passing through the rechargeable battery (or battery strings), then inverting back to 120 V/230 V AC for powering the protected equipment. A line-interactive UPS maintains the inverter in line and redirects the battery's DC current path from the normal charging mode to supplying current when power is lost. In a standby ("off-line") system the load is powered directly by the input power and the backup power circuitry is only invoked when the utility power fails. Most UPS below 1 kVA are of the line-interactive or standby variety which are usually less expensive.

For large power units, dynamic uninterruptible power supplies are sometimes used. A synchronous motor/alternator is connected on the mains via a choke. Energy is stored in a flywheel. When the mains power fails, an Eddy-current regulation maintains the power on the load as long as the flywheel's energy is not exhausted. DUPS are sometimes combined or integrated with a diesel generator that is turned on after a brief delay, forming a diesel rotary uninterruptible power supply (DRUPS).

A fuel cell UPS has been developed in recent years using hydrogen and a fuel cell as a power source, potentially providing long run times in a small space.

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. A UPS differs from an auxiliary or emergency power system or standby generator in that it will provide near-instantaneous protection from input power interruptions, by supplying energy stored in batteries or a flywheel. The on-battery runtime of most uninterruptible power sources is relatively short (only a few minutes) but sufficient to start a standby power source or properly shut down the protected equipment.

A UPS is typically used to protect computers, data centers, telecommunication equipment or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious business disruption or data loss. UPS units range in size from units designed to protect a single computer without a video monitor (around 200 VA rating) to large units powering entire data centers or buildings. The world's largest UPS, the 46-megawatt, Battery Electric Storage System (BESS), in Fairbanks, AK, powers the entire city and nearby rural communities during outages.

Submarines and ocean going vessels and design issues

   

Submarines and ocean going vessels

Battery rooms are found on diesel-electric submarines, where they contain the lead-acid batteries used for undersea propulsion of the vessel. Even nuclear submarines contain large battery rooms as backups to provide maneuvering power if the nuclear reactor is shutdown. Batteries in surface vessels may also be contained in a battery room.

Battery rooms on ocean-going vessels must prevent seawater from contacting battery acid, as this could produce toxic chlorine gas. This is of particular concern on submarines.

Design issues

Since several types of secondary batteries give off hydrogen and oxygen if overcharged, ventilation of a battery room is critical to maintain the concentration below the lower explosive limit.

The life span of secondary batteries is reduced at high temperature and the energy storage capacity is reduced at low temperature, so a battery room must have heating or cooling to maintain the proper temperature.

Batteries may contain large quantities of corrosive electrolytes such as sulfuric acid used in lead-acid batteries or potassium hydroxide used in nickel-cadmium batteries. Materials of the battery room must resist corrosion and contain any accidental spills. Plant personnel must be protected from spilled electrolyte. In some jurisdictions, large battery systems may contain reportable amounts of sulfuric acid, a concern for fire departments. Battery rooms in industrial and utility installations typically have an eye-wash station or decontamination showers nearby, so that workers who are accidentally splashed with electrolyte can immediately wash it away from the eyes and skin.

Electrical utilities of battry

     Battery rooms are also found in electric power plants and substations where reliable power is required for operation of switchgear, critical standby systems, and possibly black start of the station. Often batteries for large switchgear line-ups are 125 V or 250 V nominal systems, and feature redundant battery chargers with independent power sources. Separate battery rooms may be provided to protect against loss of the station due to a fire in a battery bank. For stations that are capable of black start, power from the battery system may be required for many purposes including switchgear operations.

The world's largest battery is in Fairbanks, Alaska, composed of Ni-Cd cells. Sodium-sulfur batteries are being used to store wind power.

Telecommunications

     Telephone system central offices contain large battery systems to provide power for customer telephones, telephone switches, and related apparatus. Terrestrial microwave links, cellular telephone sites, fibre optic apparatus and satellite communications facilities also have standby battery systems, which may be large enough to occupy a separate room in the building. In normal operation power from the local commercial utility operates telecommunication equipment,and batteries provide power if the normal supply is interrupted. These can be sized for the expected full duration of an interruption, or may be required only to provide power while a standby generator set or other emergency power supply is started.

Batteries often used in battery rooms are the flooded lead-acid battery, the valve regulated lead-acid battery or the nickel–cadmium battery. Batteries are installed in groups. Several batteries are wired together in a series circuit forming a group providing DC electric power at 12, 24, 48 or 60 volts (or higher). Usually there are two or more groups of series-connected batteries. These groups of batteries are connected in a parallel circuit. This arrangement allows an individual group of batteries to be taken offline for service or replacement without compromising the availability of uninterruptible power. Generally, the larger the battery room's electrical capacity, the larger the size of each individual battery and the higher the room's DC voltage.

telephony and Telecommunications networks and data centers

       A local backup battery unit is necessary in some telephony and combined telephony/data applications built with use of digital passive optical networks. 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 (VRLA) 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.

computer battries

        Modern personal computer motherboards 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 controllers often contain onboard disk buffer, 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".

aircraft emergency battries and burglar alarms

                 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-cadmium 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.

Burglar alarms

      Backup batteries are almost always used in burglar alarms. 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.

battry backup

      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.

     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. Batteries provide direct current (DC) electricity, which may be used directly by some types of equipment, or which may be converted to AC byuninterruptible power supply (UPS) equipment. The batteries may provide power for minutes, hours or days depending on the electrical system design, although most commonly the batteries power the UPS during brief electric utility outages lasting only seconds.

Battery rooms were used to segregate the fumes and corrosive chemicals of wet cell batteries from the operating equipment; a separate room also allowed better control of temperature and ventilation for the batteries. In 1890 the Western Union central telegraph office in New York City had 20,000 wet cells, mostly primary zinc-copper type, in use.