A sealed lead acid battery.

Lead-acid batteries, invented in 1859 by French physicist Gaston Planté, are a type of galvanic cell and are the most commonly used rechargeable batteries today. They also represent the oldest design with one of the lowest energy-to-weight ratios besides the Nickel-iron battery, commonly around 30 Wh/kg. Also, the energy-to-volume ratio is low compared to other types of batteries. The power-to-weight ratio can be quite high, however. They are relatively low-cost and can supply high surge currents needed in starter motors. Every reasonably modern car uses a lead-acid battery for this purpose. They are also used in vehicles such as forklifts, in which the low energy-to-weight ratio may in fact be considered a benefit since the battery can be used as a counterweight. Image File history File links Lead_acid_cell. ... Image File history File links Lead_acid_cell. ... A physicist is a scientist trained in physics. ... The Galvanic cell, named after Luigi Galvani, consists of two metals connected by an electrolyte which forms a salt bridge between the metals. ... Rechargeable batteries are batteries that can be restored to full charge by the application of electrical energy. ... // Technical usage in physical sciences Established official technical definition : In the physical sciences, the weight of an object has a particular technical meaning. ... The nickel-iron battery is a storage battery having a nickel oxide cathode and an iron anode, with an electrolyte of potassium hydroxide. ... GEE GUY dimensions is called content. ... Power-to-weight ratio is a measure commonly used when comparing various vehicles (or engines), including automobiles, motorcycles and aircraft. ... A current of short duration that occurs when power is first applied to capacitive loads or temperature dependent resistive loads such as tungsten or molybdenum heaters-usually lasting no more than several cycles. ... Image:Turbo starter. ... This article or section does not cite its references or sources. ... US airman operates forklift at a truck A forklift is a powered industrial truck used to hoist and transport materials by means of steel forks inserted under the load. ... This article or section does not cite its references or sources. ...

Lead-acid car batteries for a '12 volt' system consist of six cells of 2.1 V nominal voltage. Each cell contains (in the charged state) electrodes of lead metal (Pb) and lead (IV) oxide (PbO₂) in an electrolyte of about 37 % (or 6-12M) w/w sulfuric acid (H₂SO₄). Some modern designs have gelified electrolytes. In the discharged state both electrodes turn into lead(II) sulfate and the electrolyte turns into water. (This is why discharged lead-acid batteries with gelled electrolytes can freeze.) General Name, Symbol, Number lead, Pb, 82 Chemical series poor metals Group, Period, Block 14, 6, p Appearance bluish white Atomic mass 207. ... Sample of lead dioxide Lead dioxide, PbO2, also plumbic oxide, lead peroxide, is an oxide of lead, with lead in oxidation state +4. ... An electrolyte is a substance that dissociates into free ions when dissolved (or molten), to produce an electrically conductive medium. ... Sulfuric acid (British English: sulphuric acid), H2SO4, is a strong mineral acid. ... A gel (from the lat. ... Lead (II) sulfate (PbSO4) is a white crystal or powder. ... Water (from the Old English waeter; c. ...

Lead acid batteries designed for starting service, such as those in used in most automobiles, are not designed for deep discharge. Deep cycling will result in capacity loss and ultimately in premature failure, as the electrodes disintegrate due to mechanical stresses that arise from cycling. A common misperception is that starting batteries should always be kept on float charge. In reality, this practice will encourage corrosion in the electrodes and result in premature failure. Starting batteries should be kept open-circuit but charged regularly (at least once every two weeks) to prevent sulfation.

Specially designed deep-cycle cells are much less susceptible to degradation due to cycling, and are required for applications where the batteries are regularly discharged. Marine batteries are something of a compromise between the two, able to be discharged to a greater degree than automotive batteries, but less so than deep cycle batteries.

Many vendors sell chemical additives (solid compounds as well as liquid solutions) that supposedly reduce sulfate build up and improve battery condition when added to the electrolyte of a vented lead-acid battery. Such treatments are rarely, if ever, effective.

The following are general voltage ranges for six-cell lead-acid batteries:

• Quiescent(open-circuit) voltage at full charge: 12.6 V
• Unloading-end: 11.8 V
• Charge with 13.2-14.4 V
• Gassing voltage: 14.4 V
• Continuous-preservation charge with max. 13.2 V
• After full charge the terminal voltage will drop quickly to 13.2 V and then slowly to 12.6 V.

The actual voltage performance and charging guidelines for lead-acid batteries vary with the design and application of the battery.

The energy to weight ratio, or specific energy, of conventional batteries is in the range of 108 kJ/kg (30 Wh/kg).

The chemical reactions are (charged to discharged):

Anode (oxidation):

Cathode (reduction):

Because of the open cells with liquid electrolyte in most lead-acid batteries, overcharging with excessive charging voltages will generate oxygen and hydrogen gas, forming an extremely explosive mix. This should be avoided. Caution must also be observed because of the extremely corrosive nature of sulfuric acid. General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ...

Environmental Concerns

Currently attempts are being made to develop alternatives to the lead-acid battery (particularly for automotive use) because of concerns about the environmental consequences of improper disposal of old batteries. Lead-acid battery recycling is one of the most successful recycling programs in the world, with over 97% of all battery lead recycled between 1997 and 2001.^[1] Effective Lead pollution control system is a necessity for sustainable Environment, We have seen continuous improvement in Battery Recycling Plants and furnace designs for greater efficiencies.These Battery Recycling Plants are Eco Friendly as they follow all Emission Standards for Lead Smelters, but we have to devise new methods or develop alternatives to the lead-acid battery so that we can reduce the lead pollution to almost negligible amount. Lead-acid batteries react less violently to fire exposure than Nickel-cadmium batteries thus they are used in emergency lighting in case of power failure.   The international symbol for recycling. ... A power outage is the loss of the electricity supply to an area. ...

Other applications

Wet cells designed for deep discharge are commonly used in golf carts and other battery electric vehicles, large backup power supplies for telephone and computer centers and off-grid household electric power systems. Golf carts A golf cart is a small vehicle designed originally to carry two golfers and their golf clubs around a golf course faster and with less effort than walking. ... // Battery electric vehicles or BEVs are electric vehicles whose main energy storage is in the chemical energy of batteries. ...

Gel cells are used in back-up power supplies for alarm and smaller computer systems (particularly in uninterruptable power supplies) and for electric scooters, electrified bicycles and marine applications. Unlike wet cells, gel cells are sealed, so they are less prone to spilling and do not require maintenance of electrolyte levels.

Absorbed glass mat (AGM) cells are also sealed and used in battery electric vehicles.

Historically, lead-acid batteries were used to supply the filament (heater) voltage (usually between 2 and 12 volts with 6 V being most common) in vacuum tube (valve) radio receivers in areas where no mains electricity supply was available. Such radios typically used two batteries: a lead-acid "A" battery for the filament voltage and a higher voltage (45 V–120 V) "dry" non-rechargable "B" battery for the plate (anode) voltage. A few sets also used a third (3 V–9 V with several taps) "dry" non-rechargable "C" battery for grid bias. In electronics, a vacuum tube (U.S. and Canadian English) or (thermionic) valve (outside North America) is a device generally used to amplify, or otherwise modify, a signal by controlling the movement of electrons in an evacuated space. ... In electronics, an A battery is any battery used to provide power to the filament of a vacuum tube. ... In electronics, a B battery is any battery used to provide the plate voltage of a vacuum tube. ... In electronics, a C battery is any battery used to provide bias to the control grid of a vacuum tube. ...

See also

• Car battery
• Gel Battery
• Absorbed glass mat AGM
• Uninterruptible power supply

Lead-acid car battery // A car battery is a type of electric battery that supplies electric energy to the starter motor and the ignition system of a vehicle’s engine. ... A gel battery is a lead-acid battery with gelified electrolyte. ... Absorbed glass mat Absorbed glass mat (AGM) is a class of lead-acid battery in which the electrolyte is absorbed into a fibreglass mat. ... An uninterruptible power supply, or UPS, is a device or system that maintains a continuous supply of electric power to certain essential equipment that must not be shut down unexpectedly. ...

References

• U.S. Department of Energy, Primer On Lead-Acid Storage Batteries [1] (pdf).
• Environment Friendly Battery Recycling

[2] 2006 (MMVI) is a common year starting on Sunday of the Gregorian calendar. ... June 1 is the 152nd day of the year in the Gregorian calendar (153rd in leap years), with 213 days remaining. ...

External links

• Case Studies in Environmental Medicine - Lead Toxicity
• National Pollutant Inventory - Lead and Lead Compounds Fact Sheet
• ToxFAQs™: Lead