Absorbent glass mat (AGM) is a class of VRLA lead-acid battery in which the electrolyte is absorbed into a fiberglass mat. The plates in an AGM battery may be flat like wetcell lead-acid battery, or they may be wound in a tight spiral. Their unique (for lead acid chemistries) construction also allows for the lead in their plates to be purer as they no longer need to support their own weight as in traditional cells. Their internal resistance is lower than traditional cells due to close plate proximity and the pure lead plates have lower resistivity, they handle higher temperatures better, and self discharge more slowly. VRLA stands for valve regulated lead acid and is the designation for maintenance-free lead-acid batteries. ... A valve-regulated, sometimes called sealed, lead acid battery Lead-acid batteries, invented in 1859 by French physicist Gaston Planté, are the oldest type of rechargeable battery. ... An electrolyte is any substance containing free ions that behaves as an electrically conductive medium. ... Bundle of fiberglass Fiberglass (also called fibreglass and glass fibre) is material made from extremely fine fibers of glass. ... The output impedance, source impedance, or internal impedance of an electronic device is the opposition exhibited by its output terminals to the flow of an alternating current (AC) of a particular frequency as a result of resistance, induction and capacitance. ...

These batteries have a pressure relief valve which will activate when the battery is recharged at high voltage (typically greater than 2.30 volts per cell, a 12 volt battery has 6 cells). Valve activation allows some of the active material to escape thus decreasing the overall capacity of the battery.The lids (covers) typically have gas diffusers built into them that allow safe dispersal of any excess hydrogen that may be formed during overcharge. They are not permanently sealed, but are maintenance free; and they can be oriented in any manner, unlike normal lead-acid batteries which must be kept upright to avoid acid spills and to keep the plates' orientation vertical. A demonstration electrochemical cell setup resembling the Daniell cell. ... LID is an abbreviation for: Light-Weight Identity, a system that allows individuals to claim and own their digital identity on the Internet League for Industrial Democracy Library Interchange Definition This is a disambiguation page — a list of pages that otherwise might share the same title. ... Look up cover in Wiktionary, the free dictionary. ... Overcharge is an economic term that refers to the difference between an observed market price and a price that would have been observed in the absence of collusion. ...

Their specific power is very good and they can be charged and discharged quite rapidly, however their specific energy tends to be lower than traditional flooded batteries. They are often used in high performance electric vehicles due to their high power density. In engineering, specific power (sometimes also power per unit mass or power density) refers to the amount of power delivered by an energy source, divided by some measure of the sources size or mass. ... The fuel value or relative energy density is the quantity of potential energy in fuel, food or other substance. ... An electric vehicle is a vehicle that is propelled by electric motors. ... In engineering, specific power (sometimes also power per unit mass or power density) refers to the amount of power delivered by an energy source, divided by some measure of the sources size or mass. ...

In cylindrical AGM's, the plates are thin and wound, like most consumer disposable and rechargeable cells, into spirals so they are also sometimes referred to as spiral wound.

In high grade and military spec AGM's the plates are thin and hand wrapped in envelopes to discourage short circuiting due to vibration².

AGM, rechargeable batteries usually come in large sizes.

Applications

Many modern motorcycles on the market utilize AGM or factory-sealed AGM batteries for the combined benefits of reduced likelihood of acid-spilling during accidents, and for packaging reasons (lighter, smaller battery to do the same job, battery can be installed at odd angles if needed for the design of the motorcycle). A motorcycle (or motorbike) is a two-wheeled vehicle powered by an engine. ...

New 5 series BMWs from March 2007 incorporate AGM batteries in conjunction with devices for recovering brake energy using regenerative braking and a more sophisticated use of computer control to ensure the alternator charges the battery when the car is decelerating.[1] The BMW 5-Series is a series of medium size automobiles manufactured by BMW in Germany. ... For other uses, see BMW (disambiguation). ... Regenerative braking is any technology which allows a vehicle to recapture and store part of the kinetic energy that would otherwise be lost to heat when braking. ...

NASCAR, IHRA, SCORE, and other top racing leagues are continually seeing AGM products introduced into their vehicles. This is due in large part to the fact that these batteries are vibration resistant. Jeff Burton (99), Elliott Sadler (38), Ricky Rudd (21), Dale Jarrett (88), Sterling Marlin (40), Jimmie Johnson (48), and Casey Mears (41) practice for the 2004 Daytona 500 The National Association for Stock Car Auto Racing (NASCAR) is the largest sanctioning body of motorsports in the United States. ... The International Hot Rod Association also known as IHRA is the 2nd largest drag racing organization after the NHRA External link http://www. ... Look up score in Wiktionary, the free dictionary. ...

Deep-cycle AGM's are also commonly used in large-scale amateur robotics. Two examples are the FIRST and IGVC competitions. For other uses, see first. ...

Examples

• 1 Absorbed Power Australia Absorbed Power Australia

See also

• Car battery