Wednesday, July 13, 2011

History and Origin of Laptop Batteries

The battery is an important component of the laptop. It gives the laptop the power of mobility. The efficiency and performance of the laptop greatly depends on the battery when the laptop is not connected to a power outlet. The improved power and increased backup time of laptop batteries is one of the main reasons for the growing popularity of laptops. The modern laptop batteries are far more advanced than their early predecessors.

Laptop batteries have come a long way since their inception. Older laptop batteries were quite heavy and did not provide good backup time.  

History of Laptop Batteries:

Early 80s:
  • AA Batteries:
 You will be surprised to know that older laptops used to run on AA batteries. Many AA batteries were required to run a laptop, and though there were many AA batteries fitted in the laptop, they did not have a long life. The number of AA cells also increased the weight of the laptop. Running a laptop on AA batteries was quite an expensive proposition, and the batteries needed to be changed frequently. The use of AA batteries was also not good for the environment. The discarded AA batteries contained harmful chemicals and only added to environmental waste.

Late 80s:
  •  Lead-Acid Cell:

In the late 80s, laptops ran on heavy lead acid batteries.  These batteries made the laptop very heavy and did not provide any good backup time. The lead-acid cell, however, was the first rechargeable battery to be invented.

Gaston Plante invented the lead -acid cell. It was the first battery that could be recharged by passing a reverse current through it. The lead-acid cell consisted of a lead anode and lead dioxide cathode, and both were immersed in sulphuric acid. Both electrodes of the lead-acid cell reacted with sulphuric acid to produce lead sulfate. 

The reaction caused the lead anode to release electrons, while the reaction at the lead dioxide end consumed the electrons, causing a flow of electric current. The chemical reaction within the cell was reversed by passing a reverse current through it, which was equivalent to recharging the lead-acid cell.

Though these batteries were heavy, they had a considerable capacity to hold electrical charge. The Macintosh portable was powered by a sealed lead-acid cell battery.  However, lead acid batteries were soon discarded when nickel cadmium batteries were invented.

Wednesday, June 15, 2011

Li-Ion Laptop Battery Care Tips

A Li-ion battery for laptops is a battery made up of lithium – ion. To increase its life you will need to understand methods to care for the Li-Ion Laptop Battery. This battery, also referred to as LIB, comes from battery types that are rechargeable in nature. During the time of discharge, the ions of lithium move from electrodes that are negative to electrodes that are positive and return back throughout charging. In all the different kinds of LIB batteries characteristics in terms of safety, chemistry, cost as well as performance vary a lot.  

As a far as electronic items used by consumers are concerned, batteries made from lithium ion are very common. For electronic items that are portable, these rechargeable battery types are extremely popular. They are known to have the best of densities in terms of energy with absence of any effect on memory. When the battery is not being used the discharge loss is very low.  Besides being used in a number of electronic items by consumers the LIBs are also popularly used in applications in aerospace, vehicles that run on electricity as well as the military field. 

original lbm lenovo notebook batteries

The traditional battery is being researched upon where more focus is laid on intrinsic safety, durability as well as energy density of the battery, its cost as well as technology. In the past, the batteries used in laptops were very easy to charge. A circuit had to be built for voltage adjustment to ensure that charging did not exceed the capacity needed as per the mAh or the milliamp of the laptop battery. With the right kind of care for Li-Ion Laptop Battery its longevity can be improved significantly.

To get the laptop battery charged it would take a couple of hours. Life of batteries would get degraded slightly if at all if the battery underwent over charging or under charging anytime. Due to advancement in technology it is now more convenient to use the Li-ion computer batteries for laptops. As far as charging is concerned these laptop batteries, are considered the unforgiving kinds. For completing the charging cycle strict curves need to be followed in terms of voltage and charging current.  

Around three complete hours are needed for the charging of this battery which is unique to the Li-Ion variety. Current at low levels cannot be tolerated by the laptop computer batteries of the lithium ion types. For controlling the limit of current and for charging the battery a special circuit is needed especially at the time when the computer laptop battery reaches full charge. To help in regulating the charge in the laptop battery, a circuit that is sophisticated is used. Due to this, the current too gets discharged properly and the circuit in turn is able to communicate with the laptop properly about the capacity left for charging. 

It is over a particular data bus that the communication takes place. This data bus is basically tied to software dealing with the management of power that is installed in the laptop computer system. An application called Control Panel is well known to a lot of users which helps in getting an estimate on the remaining life of the battery. Minimization of consumption of power is possible as the settings within the battery help in maintaining the right kind of control. 

Features like protection of temperature levels are also present in the charging circuit in the Li-Ion Laptop Battery. Control of temperature is needed for preventing any kind of over heating or over charge. In the case of certain computer laptop batteries a thermal fuse helps in the achievement of this functionality especially when the temperature gets beyond fifty to sixty degree Celsius. A thermal sensitive resistor or a thermistor is used in other laptop battery designs. The thermistor proves to be very beneficial in communicating the temperature of the laptop battery to the circuit responsible for charging. 

After this communication is done, the process of charging stops especially when over heating takes place. To improve the life of the Lithium ion laptop battery, the management of temperature within the battery is very important. The advantages of lithium ion batteries are many, the reason why they are considered as the most sought after real value batteries. They are able to fit into a number of devices and power them as they come in a variety of sizes as well as shapes. As compared to other batteries which are equivalent in terms of energy, the lithium ion batteries are much lighter. 

The open circuit voltage is high as compared to batteries of the aqueous types which help in rise of power amount for enabling transfer of power to a current that is lower. The other advantage is the absence of any sort of memory effect. Batteries of nickel metal hydride have more self discharge as compared to lithium ion laptop batteries which have extremely low self discharge. Materials used for making the components of these batteries are completely environment safe. But, you need to care for lithium ion laptop batteries as rupture of cells and thermal runway can take place. Timely help and maintenance are the key requirements for any battery actually. 

Combustion can also take place in extreme cases. Short circuit can take place in the cells of these laptop computer batteries due to deep discharge. Risks can be reduced and with care taken in time, the Li-Ion Laptop Battery functionality improves due to the circuitry that is fail-safe which helps in timely shut down especially when the voltage is not in a safe range. In each of the cells, a number of safety features are addressed like for the internal pressure there is the tear away tab, for controlling over temperature there is the shut down separator, relief from pressure is provided by the vent and over charging and over current is controlled by the thermal interrupt. All the guidelines on this battery type are available online. To give your battery in the laptop longevity you need to heed advice and use it correctly.