Modern battery development dates as far back as the late 18^th century. The cause was championed by the work carried out by Luigi Galvani from 1780 to 1786. Through his experiments Galvani observed that, when connected pieces of iron and brass were applied to frog’s legs, they caused them to twitch. However, Galvani thought that the effect originated in the leg tissue. Nevertheless, Galvani had laid the cornerstone for further developments in "voltaic" electricity.

From 1796 - 1799, Alessandro Volta experimented with zinc and silver plates to produce electric currents at the Pavia University. Volta stacked the two to form a "pile", the first "dry" battery. By 1800 Volta had created the "crown of cups", a modified arrangement of zinc and silver discs dipped in a salt solution.

Allesandro Volta

In the years that followed other means of producing electricity were invented, all of which involved the use of liquid electrodes. Those developed by Bunsen (1842) and Grove (1839) were amongst the most successful systems, and, were used for many years.

By 1866, Georges Leclanche, a French engineer, patented a new system, which was immediately successful. In the space of two years, twenty thousand of his cells were being used in the telegraph system. Leclanche's original cell was assembled in a porous pot. The positive electrode consisted of crushed manganese dioxide with a little carbon mixed in. The negative pole was a zinc rod. The cathode was packed into the pot, and a carbon rod was inserted to act as a currency collector. The anode or zinc rod and the pot were then immersed in an ammonium chloride solution. The liquid acted as the electrolyte, readily seeping through the porous cup and making contact with the cathode material. Leclanche's "wet"cell (as it was popularly referred to) became the forerunner to the world's first widely used battery, the zinc carbon cell.

Leclanche's invention, which was quite heavy and prone to breakage, was steadily improved over the years. The idea of encapsulating both the negative electrode and porous pot into a zinc cup was first patented by J.A. Thiebaut in 1881. But, it was Carl Gassner of Mainz who is credited as constructing the first commercially successful "dry" cell. Variations followed. By 1889 there were at least six well-known dry batteries in circulation. Later battery manufacturing produced smaller, lighter batteries, and the application of the tungsten filament in 1909 created the impetus to develop batteries for use in torches.

The production of batteries was greatly increased during the First World War as a means of powering torches, field radios. Other milestones in battery production include the widespread radio broadcasting, which brought battery-operated wireless into the heart of many homes. But, it was during the inter-war years that battery performance was greatly enhanced. This was achieved through better selection of materials and methods of manufacture.

Batteries have now become an essential part of everyday life. They are the power source for millions of consumer, business, medical, military and industrial appliances worldwide. This demand is growing.  The term 'battery' comes from having a number (a battery) of separate cell cases all joined together by electrical connections.  These days the electrical connections and cells are normally included in one casing, such as in a car battery - in this case six 2 volt lead-acid cells totaling 12 volts.

There are many types of battery but they all store energy as chemical potential - i.e. two chemicals which react in a solution when a circuit is made.  There are primary and secondary cells.  Primary cells use the chemical components of the battery itself to produce energy (this includes fuel cells).  When the components are used the battery is discarded, except in a fuel cell where the fuel spent can be replaced.  Secondary cells, or accumulators may be re-charged many times over.  

The most common type of secondary cell is the "lead-acid" type used to start motor car engines.  Taken to the extreme lead-acid batteries can produce a very high output for a short duration, an example of which is the Hawker SBS range of aircraft starter batteries.  These batteries are the least expensive but have a limited life and store less energy per pound than other types.

Until a few years ago "nickel-cadmium" batteries were the most popular rechargeable small cells with a capacity measured in amp-hours, nearing twice that of lead-acid and 1.2 volts per cell.  Nickel-cadmium is not so popular now as "nickel-metal-hydride" batteries were developed for automotive use and lately produced in popular AA sizes.  NiMh cells are now very popular batteries for cameras, mobile phones, etc, with much better storage and 1.5 volts per cell and at about the same price as NiCads - but still more than lead-acid, until that is, the lifespan is taken into account when NiMh start to look attractive.

Polymer cells such as produced by Worley International offer still higher storage capacity per kilo but are much more expensive again.  These cell are used for exotic applications such as solar car racing and land speed record vehicles.

Solar Navigator needs sufficient storage capacity to even out the vagaries of natural supply, after the global weather system has had its say.  Fortunately, BP has a number of monitoring stations around the world constantly measuring incoming radiation so we have a good idea what to expect.  The battery banks of Solarnavigator must cater for the worst scenario and still keep something in reserve for a rainy day.  

Imagine: There has been no Sun for several days.  To maintain steerage and conserve energy Solar Navigator has been cruising at 1/4 speed waiting for the weather to break.  The emergency reserve is coming close and then unfavourable winds threaten to drive you close to an approaching land mass. This is what the reserve was intended for - to keep you out of trouble.  Hence never use your emergency reserve, unless for an emergency situation.

EDUCATIONAL LINKS

testking 646-206 646-365 642-889 braindumps LX0-101 1z0-821 70-576 642-648 ccna 100-101

http://www.testking.com/techking/tips/14-outstanding-sites-to-help-you-find-a-great-domain-name/

certkiller SY0-301 70-648 117-101 braindumps 000-080 000-195 050-720 70-680 ccie 70-417

http://www.examsheets.com/exam/642-165.htm

http://www.testkingsite.com/microsoft/70-681.html

The Solar Navigator - SWASSH (Small Waterplane Area Stabilized Single Hull) test model 2012

The latest Solarnavigator is designed to be capable of an autonomous world navigation set for an attempt 

in 2015 if all goes according to schedule.