Product category:
PCs and Embedded Systems
News Release from: Saft Rechargeable Battery Systems | Subject: LO26SHX lithium sulphur dioxide battery pack
Edited by the Engineeringtalk Editorial
Team on 03 February 2000
Lithium batteries vital in flight
defibrillators
How the LO26SHX lithium sulphur dioxide 12 Volt primary battery pack powers LIFEPAK 500 automated external defibrillator.
The LIFEPAK 500 automated external defibrillator (AED), now carried as standard equipment on each of British Airways' 250 aircraft, is powered by a long-life, high power Saft lithium sulphur dioxide battery pack This primary (non-rechargeable) 12 Volt battery will not only power the LIFEPAK for around 300 individual discharges, it also enables the equipment to remain unused for up to four years yet still be relied on to power up immediately should an emergency arise
AEDs are designed to enable people without extensive medical expertise to treat ventricular fibrillation (VF) the most common cause of sudden cardiac arrest.
In VF the heart quivers ineffectively and is unable to pump blood throughout the body, The AED supplies a powerful electrical shock, known as defibrillation, that interrupts the VF and allows the heart's normal rhythm to regain control.
Without treatment the patient will die within minutes.
The product carried by British Airways is the LIFEPAK 500 AED, manufactured by Medtronic Physio-Control.
This rugged, compact and portable device weighs in at only seven pounds (3.2 kg).
Its low maintenance requirements and intuitive operation, aided by concise voice prompting, audio warnings and instructions displayed on an LED screen, makes it ideal for use by infrequent AED users such as cabin staff.
The LIFEPAK 500 AED is offered with a choice of a rechargeable battery or a primary battery.
Safety legislation and the need to keep maintenance to an absolute minimum dictated the primary battery option for airline usage.
Lithium sulphur dioxide cells - the high power, long life option Medtronic Physio-Control selected a lithium type battery for the 500 because of the higher energy density available in lithium cells.
More specifically, Saft lithium sulphur dioxide cells were specified for a number of reasons: * Lithium sulphur dioxide cells are available in a cell size that provides excellent capacity and current delivery capability for long term defibrillator operation.
They provide the 500 with the longest battery life rating of any AED - a minimum of 230 full discharges and typically over 300.
This reduces the cost of ownership and maintenance since the battery needs to be changed less frequently.
In addition, this feature combines with the extremely long shelf-life (four years in aircraft use) to eliminate one of the most common problems reported with defibrillators: depleted batteries.
* Lithium sulphur dioxide cells have a history of use in rugged military applications where durability and the capability to withstand extreme environmental conditions are important.
Many AEDs are stored and transported in uncontrolled environments where similar demands apply.
* Lithium sulphur dioxide batteries operate effectively over a broader temperature range than other lithium cells.
This enables them to charge a defibrillator faster at lower temperature extremes and throughout battery life.
* Lithium sulphur dioxide cells lend themselves to the design of simple and reliable circuits for low-battery detection.
This eliminates the need for extra sensing cells or complicated detection techniques that are required for other lithium cell types.
Reliable detection of a depleted battery is a vital feature for a defibrillator with a user-replaceable battery.
The battery supplied by Saft for the LIFEPAK 500 AED comprises a pack of four LO26SHX 'D' hermetically sealed cells wired in series.
This provides a nominal voltage of 12 Volts and a capacity of 7.5 Ah in a pack weighing just under two pounds (0.9 kg).
Safety precautions include an 8 A fuse and series thermal cut-outs mounted to each of the cells.
All of the individual cells, as well as the battery pack itself, include a safety vent to release pressure.
A six-page colour datasheet detailing Saft's primary lithium batteries is available. Request a free brochure from Saft Rechargeable Battery Systems ...
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