The leading health indicator of a battery is capacity

June 14 [Fri], 2013, 15:08
Battery testing can be guesswork and the lack of effective test methods results in batteries being replaced too soon or too late (mostly too late). Some batteries are swapped repeatedly without knowing the cause A32-M50 bright of failure, but most are left untouched until a failure occurs.
The market is saturated with battery testers. Most read only voltage and internal resistance and don’t work all that well. They do find a dead or dying battery; but so does the user. Batteries have improved and resistance-related failures are isolated. This makes single-dimensional impedance that only read resistance more or less obsolete. The solution lies in two-dimensional methods, but more on this later.

The leading health indicator of a battery is capacity, a value that is difficult to appraise. Many battery testers claim to measure capacity, but this is not possible with voltage and resistance alone, nor will a load test achieve this. Advertising features that lay outside the equipment’s capabilities is misleading and confuses the industry into believing that multifaceted results are attainable with basic test methods.

Battery diagnostics is complex. We don’t even have a reliable method to measure state-of-charge (SoC). Most rely on voltage and coulomb counting; assessing capacity lags far behind. Batteries cannot be measured per se; their health can only be predicted or estimated using indirect measurements. This is synonymous with the weatherman predicting the weather. All findings are estimations with various degrees of accuracy.

Battery testing is not new. The carbon pile introduced in the 1980s applies a load for a short duration. The voltage drop reveals the internal resistance and current flow assures cranking ability. The carbon pile cannot estimate capacity but a skilled mechanic can assess a battery on its kinetic behavior.

The AC conductance meter, also known as impedance tester, appeared in 1992 and was hailed as a breakthrough. The device injects an AC signal to measure the internal resistance. Today, these testers check the CCA of starter batteries and verify the resistive change on UPS batteries. While small and easier to use, these instruments cannot measure capacity.

Critical progress has been made with electrochemical impedance spectroscopy (EIS). EIS is not new. Size, high cost, long test times and required skills to interpret results have restricted their technology to lab environments. To facilitate capacity estimation, Cadex extended EIS and developed multi-model AP32-1008P bright electrochemical impedance spectroscopy, or Spectro?. The heart of Spectro? is a patented algorithm that performs 40 million transactions while scanning the battery with 20–2,000 Hz low amplitude signals. Figure 1 illustrates the Spectro CA-12 providing capacity, CCA, and SoC in 15 second test.

There is a notion that internal resistance is related to capacity

April 19 [Fri], 2013, 14:23
The resistance of a battery provides useful information about its performance and detects hidden trouble spots. High resistance values are often the triggering point to replace an aging battery, and determining resistance is12 cells 42T5263 especially useful in checking stationary batteries. However, resistance comparison alone is not effective, because the value between batches of lead acid batteries can vary by eight percent.

Because of this relatively wide tolerance, the resistance method only works effectively when comparing the values for a given battery from birth to retirement. Service crews are asked to take a snapshot of each cell at time of installation and then measure the subtle changes as the cells age. A 25 percent increase in resistance over the original reading hints to an overall performance drop of 20 percent.

The resistance of a battery provides useful information about its performance and detects hidden trouble spots.High resistance,values are often the triggering point to replace
an aging battery,and determining resistance is especially usefuo in checking statonary batteries.However ,resistacnecomparison alone is not effective,because the value
between batches of lead acid batteries can vary by eight pecent.B

Manufacturers of stationary batteries typically honor the warranty if the internal resistance increases by 50 percent. Their preference is to get true capacity readings by applying a full discharge. It is their belief that only a discharge can provide reliable readings and they ask users to perform the service once a year. While this advice has merit, a full discharge requires a temporary disconnection of the 12 cells 51J0497from the system, and on a large battery such a test takes an entire day to complete. In the real world, very few battery installations receive this type of service and most measurements are based on battery resistance readings.

Measuring the internal resistance is done by reading the voltage drop on a load current or by AC impedance. The results are in ohmic values. There is a notion that internal resistance is related to capacity, and this is false. The resistance of many batteries stays flat through most of the service life. Figure 1 shows the capacity fade and internal resistance of lithium-ion cells.

Anyone repairing an SMBus battery needs to be aware of compliance issues

April 19 [Fri], 2013, 14:15
Some batteries are equipped with a solid-state switch that is normally in the “off” position and no voltage is present on the battery terminals; connecting the switch terminal to ground often turns the battery on. If this does not work, the pack may need a proprietary code for activation, and battery manufacturers12 cells L08S6D13 keep these codes a well-guarded secret.

How can you find the correct terminals? Use a voltmeter to locate the positive and negative battery terminals and establish the polarity. If no voltage is available, a solid-state switch in the “off” position may need activating. Connecting the voltmeter to the outer terminals, take a 100-Ohm resistor (other values may also work), tie one end to ground, and with the other end touch each terminal while observing the voltmeter. If no voltage appears, the battery may be dead or the pack will require a security code. The 100-Ohm resistor is low enough to engage a digital circuit and high enough to protect the battery against a possible electrical short.

Establishing the connection to the battery terminals should now enable charging. If the charge current stops after 30 seconds, an activation code may be required, and this is often difficult if not impossible to obtain.

Some battery manufacturers add an end-of-battery-life switch that turns the battery off when reaching a certain age or cycle count. Manufacturers argue that customer satisfaction and safety can only be guaranteed by regularly replacing the battery. Such a policy tends to satisfy the manufacturer more than the user, and newer batteries do not include this feature.

If at all possible, connect the thermistor during charging and discharging to protect the battery against possible overheating. Use an ohmmeter to locate the internal thermistor. The most common thermistors are 10 Kilo Ohm NTC, which reads 10kΩ at 20°C (68°F). NTC stands for negative temperature coefficient, meaning that the resistance decreases with rising temperature. In comparison, a positive temperature coefficient (PTC) causes the resistance to increase. Warming the battery with your hand may be sufficient to detect a small change in resistor value when looking for the correct terminal on the battery.
In some cases the chemical battery can be restored, but the fuel gauge might not work, is inaccurate, or will provide wrong information. After repackaging, the battery may need some sort of initialization/ calibration process. Simply charging and discharging the pack to reset the flags might do the trick. A “flag” is a measuring point to mark and record an event.

The circuits of some smart batteries must be kept alive during cell replacement. Disconnecting the voltage for only a fraction of a second can erase vital data in the memory. The lost data could contain the resistor value of the digitized shunt that is responsible for the coulomb counter. Some integrated circuits (IC) responsible for fuel gauge function have wires going to each cell, and the sequence of assembly must to be done in the correct order.

To assure continued operation when changing the cells, supply a secondary voltage through a 100-Ohm resistor to the circuit before disconnection and remove the supply only after the circuit receives voltage again from the 12 cells L09S6Y02new cells. Cell replacement of a smart battery has a parallel with open-heart surgery, where doctors must keep all organs of the patient alive.

Anyone repairing an SMBus battery needs to be aware of compliance issues. Unlike other tightly regulated standards, the SMBus allows some variations, and this can cause problems when matching battery packs with existing chargers. The repaired SMBus battery should be checked for compatibility before use.

The acid corroded the lead inside the battery

March 01 [Fri], 2013, 10:43
As with several of Thomas Edison’s later projects, such as his effort to mine iron ore and his quest to create synthetic rubber, his attempts at improving the battery did not lead to the results he hoped for. Edison started his work on the cheap rn873 G42in the 1890s, just after the automobile had been introduced.

At that time, the gasoline automobile was still unreliable, and steam and electric cars sold in larger numbers. One problem with electric cars, however, was that the lead-acid batteries that they used (similar to the batteries used to start gasoline-powered cars today) were extremely heavy. Another was that the acid corroded the lead inside the battery, shortening the useful life of the battery.

Edison began looking for a way to make batteries lighter, more reliable, and at least three times more powerful so that they could become the basis of a successful electric car. Edison and his team conducted tests of all sorts of metals and other materials, looking for those that would work best in batteries. The tests numbered in the thousands and lasted until 1903, when he finally declared his battery finished. The battery used potassium hydroxide, which reacted with the battery’s iron and nickel electrodes to create a battery with a strong output that was reliable and rechargeable.

As usual, Edison announced the new battery with great fanfare and made bold claims about its performance. Manufacturers and users of electric vehicles, which now included many urban delivery and transport trucks, began buying them. Then stories about battery failures started coming out. Many of the batteries began to leak, and others lost much of their power after a short while. The new nickel-graphite conductors were failing. Engineers who tested the batteries found that while lightweight, the new alkaline battery did not significantly out-perform an ordinary lead-acid battery.

Edison shut down the factory immediately, and between 1905 and 1908, the whole battery was redesigned. Edison came up with a new design, and although the new battery used more expensive materials, it had better performance and more power. By 1910, battery production was again underway at a new factory near the West Orange, NJ laboratory.

However, it was too late for the electric automobile. Edison’s friend Henry Ford had introduced the lightweight, inexpensive Model T car in 1909, which helped make the gasoline engine the standard for the automobile. The largest remaining market for the batteries was in special commercial vehicles, such as the small trucks and cars used in cities for deliveries, or inside factories to move materials around. Even here, however, Edison’s battery was somewhat less powerful than conventional lead-acid batteries.

Around 1912, gasoline automobiles would actually begin to use batteries to run their starters, but Edison’s battery was not suitable for this use because its voltage was too low. Its best feature was its reliability, whichcheap rn873 511872-001 made it popular in other applications such as providing backup power for railroad crossing signals, or to provide power for the lamps used in mines. While it did not fulfill Edison’s dream of powering the automobile, at least it was profitable, and it became one of his biggest moneymakers in later years.

A circuit provides the escape route for the newly paroled electrons

January 04 [Fri], 2013, 16:08
A battery, by definition, consists of a group of two or more primary or secondary battery cells, which convert chemical energy into electrical energy. A portion of the chemical energy a cell produces is transformed into heat, and abuy Aspire 7750 portion into an electric current.

Primary battery cells can only be renewed during down time, when they replenish their chemicals. When one reach for his or her emergency flashlight, which contains a type of primary cell named an ordinary cell, and it fails to light up, one falls victim of this very principle.

Each and every primary cell uses various chemicals, and contains electrodes and an electrolyte, a liquid. Electrodes, a.k.a. "cell elements," consist of either two different metals, or one metal and carbon. Element number one, the cathode, is primarily zinc. Element number two, the anode, is primarily carbon.

A chemical action sets the electrons free, when it triggers the cathode slowly to dissolve into the liquid electrolyte. A circuit provides the escape route for the newly paroled electrons, and they rush down the hatch in the form of an electric current. Unfortunately, their freedom is short-lived, because, once an electrical conductor is connected to the two elements, the current flowing through it is recaptured as electricity.

Secondary battery cells merit less discussion, as they automatically recharge, when an electric current is injected through them. Primary examples of a secondary battery cells are the storage cells used to start, or not to start, our car batteries. Because a storage battery does not actually store electricity, it instills in one a false sense of security. One is well advised to carry jumper cables in our cars, for those times when, much to ones chagrin, the battery fails to start.

The misnomered "storage battery," draws its power from chemical charges. Inside a storage battery, one finds a set of plates made of metallic lead, and a set made of lead peroxide. When both sets of plates are immersed in sulphuric acid, they undergo a chemical change, which transforms them into lead buy Aspire One 521sulphate, which in turn produces the electrical current in the storage battery, which does not store. A word of not try this one at home!

This technique enforces privilege separation

November 29 [Thu], 2012, 16:19

There are two different approaches to security in computing. One focuses mainly on external threats, and generally treats the computer systemhp envy Pavilion Mini 1000 battfery itself as a trusted system. This philosophy is discussed in the computer insecurity article.

The other, discussed in this article, regards the computer system itself as largely an untrusted system, and redesigns it to make it more secure in a number of ways.

This technique enforces privilege separation, where an entity has only the privileges that are needed for its function. That way, even if an attacker has subverted one part of the system, fine-grained security ensures that it is just as difficult for them to subvert the rest.

Furthermore, by breaking the system up into smaller components, the complexity of individual components is reduced, opening up the possibility of using techniques such as automated theorem proving to prove the correctness of crucial software subsystems. Where formal correctness proofs are not possible, rigorous use of code review and unit testing measures can be used to try to make modules as secure as possible.

The design should use "defense in depth", where more than one subsystem needs to be compromised to compromise the security of the system and the information it holds. Subsystems should default to secure settings, and wherever possible should be designed to "fail secure" rather than "fail insecure" (see fail safe for the equivalent in safety engineering). Ideally, a secure system should require a deliberate, conscious, knowledgeable and free decision on the part of legitimate authorities in order to make it insecure. What constitutes such a decision and what authorities are legitimate is obviously controversial.

In addition, security should not be an all-or-nothing issue. The designers and operators of systems should assume that security breaches are inevitable in the long term. Full audit trails should be kept of system replacement rn873 513775-001 activity, so that when a security breach occurs, the mechanism and extent of the breach can be determined.

Storing audit trails remotely, where they can only be appended to, can keep intruders from covering their tracks. Finally, full disclosure helps to ensure that when bugs are found the "window of vulnerability" is kept as short as possible.

The energy density of the lithium ion battery is commonly

November 29 [Thu], 2012, 16:17
Initial scientific tests with the Li-Ion battery started in 1912 with G.N. Lewis however it was not until the early 1970s that the initial non-rechargeable lithium batteries became commercially accessible.Attempts to develop rechargeable lithiumbright 607762-001followed in the 1980s,but failed due to safety concerns.

Lithium is the lightest of all metals,has the greatest electrochemical potential and gives the biggest energy density per weight.Rechargeable batteries utilizing lithium metal anodes (negative electrodes) are capable of supplying both good voltage and exceptional capacity,resulting in an extraordinary high energy density.

After much study on rechargeable lithium batteries during the 1980s,it was discovered that cycling causes adjustments on the lithium electrode.These transformations,which are part of normal wear and tear,decrease the thermal stability,creating potential thermal runaway situations.When this occurs,the cell temperature swiftly approaches the melting point of lithium,resulting in a violent reaction called “venting with flame”.A substantial number of rechargeable lithium batteries sent to Japan had to be recalled in 1991 when a battery in a mobile phone created flaming gases and caused burns to a person’s face.

There is no memory and no regular cycling is needed to prolong the battery’s life.In addition,the self discharge is less than half compared to Ni-Cd and Nickel metal hydride,making the Li-ion well suited for modern day fuel gauge applications.The high cell voltage of Li-ion battery enables the creation of battery packs comprising of only a single cell.Several of today’s cellular phones operate on a solitary cell,an advantage that simplifies battery style and design.Supply voltages of electronic apps have been heading down,which in turn calls for less cells for each battery packs.To hold the same power,however,higher currents are necessary.This emphasizes the significance of particularly low cell resistance to enable unrestricted flow of current.

Because of the underlying volatility of lithium metal,in particular throughout charging,exploration moved to a non-metallic lithium battery using lithium ions.Even though slightly reduced in energy density than lithium metal,the lithium-ion is stable,as long as particular safety measures are met when charging and discharging.In 1991,the Sony Corporation commercialized the initial lithium-ion battery.Other producers followed suit.Today,the Lithium-ion battery is the fastest developing and most promising battery chemistry.

The energy density of the lithium ion battery is commonly twice that of the typical nickel cadmium battery.Improvements in electrode active components have the potential of increasing the energy density close to 3 times that of the Nickel cadmium.In addition to good capacity,the load characteristics are fairlycheap 572032-001 good and behave similarly to the Nickel cadmium in terms of discharge attributes (comparable style of discharge profile,but different voltage).

The flat discharge curve presents productive utilization of the saved electrical power in a useful voltage range.The Li 18650 battery is a low maintenance battery,an advantage that most other technologies are unable to state.

Plug the computer into an electrical outlet and let the battery charge fully

October 09 [Tue], 2012, 12:17
Calibrating a laptop battery puts the power meter back into sync with the battery's actual "fully charged" state. It also helps the battery regain part of the power capacity it lost due to short-cycling, extending 11.1v 5200mah 9cells Vostro 1710 batterytime. Most people should calibrate laptop batteries about once every two to three months. Here's how to calibrate your battery:

Plug the computer into an electrical outlet and let the battery charge fully.
Unplug the computer and use it normally until the battery is so drained that it goes into sleep mode automatically. (The battery really has a small reserve left, but if that is used up then data will be lost because the computer will shut down completely.)
Repeat Step 1: Fully recharge the battery.

This process should also work for iPods, iPhones and other portable devices which have a battery life indicator on the screeen. Running the battery through this charge/discharge/recharge cycle should calibrate the battery and get it back in sync with the power meter display on your device.

There is some disagreement about whether this "deep discharge" should be done with Lithium-ion batteries. Apple recommends it for iPods, iPhones and other mobile devices they sell, but others claim that fully discharging battery for Inspiron 1521 batterya Lithium battery can damage it. I think the confusion comes from the fact that most devices will hibernate when the battery reaches a "critical level" of 5% remaining charge. So the battery isn't really "fully" discharged, but it's close enough to zero to make the calibration process work well enough.

The study through the use of the Graphene this magical materials

May 10 [Thu], 2012, 15:43
U.S. the Ohio Nanotek instruments researchers use lithium-ion fast shuttle movement of a large number of features, developed a new type of energy storage devices can recharge time reduced to hours at a time from the past between the graphene surface and electrodeless than a minute. The study, published in "Nano Letters".

The study through the use of the Graphene this magical materials, to avoid a power density of the lithium ion battery and increase the super capacitor energy storage density of these two huge challenge, developed a new energy storage devices, also known as graphene the surface of lithium-ion exchange batteries, referred to as surface-mediated cell (SMCS). The SMCS focus on the advantages of lithium batteries and super capacitors, and both high power density and high-capacity storage density characteristics. Although the storage device is not optimized materials and structures, but the performance has been more than a lithium ion battery and super capacitor.

The new equipment of the power density of 100 kW / kg, 100 times higher than that of commercial lithium ion battery, super capacitor 10 times higher. High power density, high energy conversion rate, the charging time will be shortened. In addition, the new battery energy storage density of 160 W / kg, with commercial lithium equivalent to 30 times higher than the traditional super capacitor. Energy storage density, the more stored energy.

Studies have shown that, in the same weight, only the not yet optimized SMC alternative to lithium ion battery, the same driving distance of the SMC or lithium ion battery electric vehicles, but the SMC charge time of less than 1 minute, while the lithium ion battery you need hours. The researchers believe that SMC performance will be better optimized.

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Lead-acid batteries as a power source of low-speed electric vehicles

May 10 [Thu], 2012, 15:41
Recently, the China Nonferrous Metals Industry Association said, the ministry will soon start the special rectification of lead-acid battery industry, and have been put forward relevant policies and regulations.

In recent years, with the widespread popularity of electric bicycles, as well as the electric car has not been nationally recognized low, lead-acid battery industry a new opportunity for development. The entire lead-acid battery industry has basically formed a system and presents a more rapid trend of development, also made a major breakthrough in environmental issues. However, according to statistics, more than 3,000 enterprises, or 9% up to environmental standards.

Some experts said that the problem of pollution generated in the battery production process and have not been well addressed, in particular the serious pollution problems of a large number of some medium-sized and small enterprises of the production process.

The main reason is that many manufacturers, small scale, are more polluting, uneven quality, some do not have the environmental conditions of workshops factory rush into mass action, about a quarter of enterprises without the approval of the environmental protection of unauthorized construction site, pollution control facilities is not complete, production is not carried out under strict environmental protection measures and industrial safety and health conditions caused harm to the operator and the ecological environment, the production license system is not strict clean production, environmental protection facilities standard this juncture. Although China since 2005, the production license system, but there are some problems in the approval and implementation, and did not really promote the production enterprises to achieve cleaner production, many manufacturers are not up to converted to legalization (currently issuing enterprise has reached 930 home), resulting in serious environmental problems.

Related to environmental protection law, there are still many imperfect and unsatisfactory. The amount of the fine for polluting enterprises, environmental protection departments is limited, can not make up for the social losses caused by industrial pollution. Meanwhile, the state is not specified, the protection of large, medium-sized battery manufacturer's policy, and local environmental protection departments also belong to the management of a small battery manufacturers only paid attention to the supervision of large and medium-sized enterprises, resulting in large and medium-sized enterprises sewage charges and monitoring costs, the "three simultaneous" evaluation fees, and a heavy burden.

In addition, in recent years, lead-acid batteries as a power source of low-speed electric vehicles in various suburbs, the rural market is emerging. However, the identity of its new energy vehicle "has not received national recognition. The more traditional lead-acid batteries, lithium ion battery has a small size, light weight, high operating voltage, specific energy, long cycle life, non-polluting and safe performance and many other advantages, the lithium battery in the current round of environmental investigation benefit.

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