A water-activated battery is a disposable
reserve battery 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 ...
that does not contain an
electrolyte and hence produces no
voltage
Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to ...
until it is soaked in
water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
for several minutes.
Description
Typically, a large variety of
aqueous solutions can be used in place of plain water. This battery type is specifically designed to pollute less (see
environmentally friendly claims) due to the lesser use or the absence of
heavy metals. Water-activated batteries have been used in
radiosonde
A radiosonde is a battery-powered telemetry instrument carried into the atmosphere usually by a weather balloon that measures various atmospheric parameters and transmits them by radio to a ground receiver. Modern radiosondes measure or calcula ...
s that shouldn't contain
heavy metals since they regularly fall to the ground or
ocean
The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the wo ...
surface, and indefinitely remain there.
Kits using copper-magnesium cells activated by water or the liquid sample itself are also in development. Another water-activated battery had been invented by Susumu Suzuki of Total System Conductor. Aluminium anodes are used on many water-activated batteries designed for use with salt water such as seawater. The HydroPak uses water-activated disposable fuel cartridges as an alternative to lead acid battery packs and portable generators. It uses water added to sodium borohydride which releases hydrogen fuel for a proton exchange membrane fuel cell. It can be re-charged simply by replacing the fuel cartridge rather than the lengthy recharging that other batteries require, however the cartridges cost $20 each.
See also
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List of battery types
This list is a summary of notable electric battery types composed of one or more electrochemical cells. Three lists are provided in the table. The primary (non-rechargeable) and secondary (rechargeable) cell lists are lists of battery chemistry. ...
*
Lemon battery
A lemon battery is a simple battery often made for the purpose of education. Typically, a piece of zinc metal (such as a galvanized nail) and a piece of copper (such as a penny) are inserted into a lemon and connected by wires. Power generated b ...
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Earth battery
An Earth battery is a pair of electrodes made of two dissimilar metals, such as iron and copper, which are buried in the soil or immersed in the sea. Earth batteries act as water activated batteries. If the plates are sufficiently far apart, they ...
References
{{reflist
Battery types
Disposable batteries