Reserve battery

Last updated June 03, 2024

A reserve battery, also called stand-by battery, is a primary battery where part is isolated until the battery needs to be used. When long storage is required, reserve batteries are often used, since the active chemicals of the cell are segregated until needed, thus reducing self-discharge.^[1]

Uses

These batteries are used in radiosondes, missiles, projectile and bomb fuzes, and various weapon systems.

While not advertised as reserve batteries, the principle is illustrated by the sale of "dry charged" car batteries where the electrolyte is added at the time of sale. Another example is zinc-air batteries where the cell is sealed until use: a tab is removed to admit air and activate the cell.^{[ citation needed ]}

Activation

Reserve batteries may be activated by addition of water, by adding electrolyte, by introducing a gas into the cell that is either the active cathode material or part of the electrolyte, or by heating a solid electrolyte to a temperature at which it becomes conductive. The missing element of the battery can be added before use in several ways. The battery can have water or electrolyte added manually, the battery can be activated when the system is dropped into the water (such as in a sonobuoy), or electrolyte can be stored in a capsule within the battery and released by mechanical means, an electrical trigger, or by spin or shock. A molten-electrolyte battery is activated by igniting a pyrotechnic heat source. The battery delivers current for a short time (seconds to a few minutes), but some thermal batteries can be stored ten years or more without deterioration. Reserve batteries remain uncommon in civilian applications because of their higher cost and relatively short life after activation.

In missiles, reserve batteries typically use a small container of pressurized air to force the electrolyte from a storage tank into the battery. For safe disposal, the air must be vented.

In ordnance, the batteries are activated by acceleration during gun firing, or by spinning the projectile in flight.^[2]

Types

Some reserve batteries are:

Aluminium battery, a variant of zinc-air battery where aluminium and air are used
Silver-zinc battery, often found in old missiles
Thermal battery, a class of battery types with molten salt as an electrolyte. The battery is in an inert state until the electrolyte melts through heating. Common in military applications, especially for missiles and proximity fuzes. Examples include V-2 rockets, AIM-9 Sidewinder, MIM-104 Patriot, BGM-71 TOW, BGM-109 Tomahawk, many nuclear weapons, and other single-use applications.
Water-activated battery, a class of batteries where the electrolyte is water that has to be added, such as HydroPak or NoPoPo.

Related Research Articles

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<span class="mw-page-title-main">Electrochemical cell</span> Electro-chemical device

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The Hall–Héroult process is the major industrial process for smelting aluminium. It involves dissolving aluminium oxide (alumina) in molten cryolite and electrolyzing the molten salt bath, typically in a purpose-built cell. The Hall–Héroult process applied at industrial scale happens at 940–980 °C and produces 99.5–99.8% pure aluminium. Recycling aluminum requires no electrolysis, thus it is not treated in this way.

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An alkaline battery is a type of primary battery where the electrolyte has a pH value above 7. Typically these batteries derive energy from the reaction between zinc metal and manganese dioxide.

A sodium–sulfur (NaS) battery is a type of molten-salt battery that uses liquid sodium and liquid sulfur electrodes. This type of battery has a similar energy density to lithium-ion batteries, and is fabricated from inexpensive and non-toxic materials. However, due to the high operating temperature required, as well as the highly corrosive and reactive nature of sodium and sodium polysulfides, these batteries are primarily suited for stationary energy storage applications, rather than for use in vehicles. Molten Na-S batteries are scalable in size: there is a 1 MW microgrid support system on Catalina Island CA (USA) and a 50 MW/300 MWh system in Fukuoka, Kyushu, (Japan).

<span class="mw-page-title-main">Zinc–air battery</span> High-electrical energy density storage device

A zinc–air battery is a metal–air electrochemical cell powered by the oxidation of zinc with oxygen from the air. During discharge, a mass of zinc particles forms a porous anode, which is saturated with an electrolyte. Oxygen from the air reacts at the cathode and forms hydroxyl ions which migrate into the zinc paste and form zincate, releasing electrons to travel to the cathode. The zincate decays into zinc oxide and water returns to the electrolyte. The water and hydroxyl from the anode are recycled at the cathode, so the water is not consumed. The reactions produce a theoretical voltage of 1.65 Volts, but is reduced to 1.35–1.4 V in available cells.

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A water-activated battery is a disposable reserve battery that does not contain an electrolyte and hence produces no voltage until it is soaked in water for several minutes.

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<span class="mw-page-title-main">NASICON</span> Class of solid materials

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References

↑ David Linden, Thomas B. Reddy (ed). Handbook Of Batteries 3rd Edition. McGraw-Hill, New York, 2002 ISBN 0-07-135978-8, chapter 16
↑ http://www.wipo.int/pctdb/en/wo.jsp?wo=2005093883&IA=WO2005093883&DISPLAY=DESC ^{[ dead link ]}

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[1] David Linden, Thomas B. Reddy (ed). Handbook Of Batteries 3rd Edition. McGraw-Hill, New York, 2002 ISBN 0-07-135978-8, chapter 16

[2] ttp://www.wipo.int/pctdb/en/wo.jsp?wo=2005093883&IA=WO2005093883&DISPLAY=DESC ^{[ dead link ]}

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