The battery management system to stop the false warning messages

June 17 [Mon], 2013, 17:22
The Volkswagen Beetle in simpler days had minimal battery problems. The only management system was ensuring that the Aspire 7750 replacementwas being charged while driving. Onboard electronics for safety, convenience, comfort and pleasure have greatly added to the demands on the battery in modern cars since then.


For the accessories to function reliably, the state-of-charge of the battery must be known at all times. This is especially critical with start-stop technologies, a mandated requirement on new European cars to improve fuel economy.
When the engine stops at a red light, the battery draws 25–50 amperes of current to feed the lights, ventilators, windshield wipers and other accessories. When the light changes, the battery must have enough charge to crank the engine, which requires an additional 350A. With the engine started again and accelerating to the posted speed limit, the battery begins charging after a 10-second delay.

Realizing the importance of battery monitoring, car manufacturers have added battery sensors that measure voltage, current and temperature. Packaged in a small housing that forms part of the positive clamp, the electronic battery monitor(EBM)provides useful information about the battery and provides an accuracy of about +/–15 percent when the battery is new. As the battery ages, the EBM begins drifting and the accuracy drops to 20-30 percent. The model used for monitoring the battery is simply not able to adjust. To solve this problem, EBM would need to know the state-of-health of the battery, and that includes the all-important capacity. No method exists today that is fully satisfactory, and some mechanics disconnect the battery management system to stop the false warning messages.


A typical start-stop vehicle goes through about 2,000 micro cycles per year. Test data obtained from automakers and the Cadex laboratories indicate that with normal usage in a start-stop configuration, the battery capacity drops to approximately 60 percent in two years. Field use reveals that the standard flooded lead acid lacks robustness, and carmakers are reverting to a modified version lead acid battery. Read about Environmental Concerns.

Automakers want to ensure that no driver gets stuck in traffic with a dead battery. To conserve energy, modern cars automatically turn off unnecessary accessories when the battery is low and the motor stays running at a stoplight. Even with this measure, state-of-charge can remain low if commuting in gridlock conditions because motor idling does not provide much charge to the battery, and with essential accessories like lights and windshield wipers on, the net effect could be a small discharge.

Battery monitoring is also important on hybrid vehicles to optimize charge levels. Intelligent charge management prevents stressful overcharge and avoids deep discharges. When the charge level is low, the internal combustion (IC) engine engages earlier than normal and is left running longer for additional charge. On a fully charged battery, the IC engine turns off and the car moves on the electrical motor in slow traffic.

Improved battery management is of special interest to the manufacturers of the electric vehicle. In terms of state-of-charge, a discerning driver expects similar accuracies in energy reserve as are possible with a fuel-powered Aspire One 521 replacement vehicle, and current technologies do not yet allow this. Furthermore, the driver of an EV anticipates a fully charged battery will power the vehicle for the same distance as the car ages. This is not the case and the drivable distance will get shorter with each passing year. Distances will also be shorter when driving in cold temperatures because of reduced battery performance.

Let’s look at how current systems work and examine

June 17 [Mon], 2013, 17:21
One of the most urgent requirements for battery-powered devices is the development of a reliable and economical way to monitor battery state-of-function (SoF). This is a demanding task when considering that there is still no dependable method to read state-of-charge, the most basic characteristic of a Aspire 7741 replacement. Even if SoC were displayed accurately, charge information alone has limited benefits without knowing the capacity.

The objective is to identify battery readiness, which describes what the battery can deliver at a given moment. SoF includes capacity (the amount of energy the battery can hold), internal resistance (the delivery of power), and state-of-charge (the amount of energy the battery holds at that moment).

Stationary batteries were among the first to include monitoring systems, and the most common form of supervision is voltage measurement of individual cells. Some systems also include cell temperature and current measurement. Knowing the voltage drop of each cell at a given load reveals cell resistance. Cell failure caused by rising resistance through plate separation, corrosion and other malfunctions can thus be identified. Battery monitoring also serves in medical, defense and communication devices, as well as wheeled mobility and electric vehicle applications.

In many ways, present battery monitoring falls short of meeting the basic requirements. Besides assuring readiness, batterymonitoring should also keep track of aging and offer end-of-life predictions so that the user knows when to replace a fading battery. This is currently not being done in a satisfactory manner. Most monitoring systems are tailored for new batteries and adjust poorly to aging ones. As a result, battery management systems (BMS) tend to lose accuracy gradually until the information obtained gets so far off that it becomes a nuisance. This is not an oversight by the manufacturers; engineers know about this shortcoming. The problem lies in technology, or lack thereof.

Another limitation of current monitoring systems is the bandwidth in which battery conditions can be read. Most systems only reveal anomalies once the battery performance has dropped below 70 percent and the performance is being affected. Assessment in the all-important 80–100 percent operating range is currently impossible, and systems give the batteries a good bill of health. This complicates end-of-life predictions, and the user needs to wait until the battery has sufficiently deteriorated to make an assessment. Measuring a battery once the performance has dropped or the battery has died is ineffective, and this complicates battery exchange systems proposed for the electric vehicle market. One maker of a battery tester proudly states in a brochure that their instrument “Detects any faulty battery.” So, eventually, does the user.

Some medical devices use date stamp or cycle count to determine the end of service life of a battery. This does not work well either, because batteries that are used little are not exposed to the same stresses as those in daily operation. To reduce the risk of failure, authorities may mandate an earlier replacement of all batteries. This causes the replacement of many packs that are still in good working condition. Old habits are hard to break, and it is often easier to leave the procedure as written rather than to revolt. This satisfies the battery vendor but increases operating costs and creates environmental burdens.

Portable devices such as laptops use coulomb counting that keeps track of the in- and out flowing currents. Such a monitoring device should be flawless, but as mentioned earlier, the method is not ideal either. Internal Aspire 7745 replacementlosses and inaccuracies in capturing current flow add to an unwanted error that must be corrected with periodic calibrations.


Over-expectation with monitoring methods is common, and the user is stunned when suddenly stranded without battery power. Let’s look at how current systems work and examine up-and-coming technologies that may change the way batteries are monitored.

A lithium-ion battery will simply power down when a short circuit occurs

May 02 [Thu], 2013, 16:29
There are two basic types of lithium-ion chemistries: cobalt and manganese (spinel). To achieve maximum runtime, cell phones, digital cameras and laptops use cobalt-based lithium-ion. Manganese is the newer of the two chemistries and offers superior thermal stability. It can sustain temperatures of up to 250°C (482°F) before becoming unstable. In addition, manganese has a very low internal resistance Presario CQ42 brand new and can deliver high current on demand. Increasingly, these batteries are used for power tools and medical devices. Hybrid and electric vehicles will be next.

The drawback of spinel is lower energy density. Typically, a cell made of a pure manganese cathode provides only about half the capacity of cobalt. Cell phone and laptop users would not be happy if their batteries quit halfway through the expected runtime. To find a workable compromise between high energy density, operational safety and good current delivery, manufacturers of lithium-ion batteries can mix the metals. Typical cathode materials are cobalt, nickel, manganese and iron phosphate.

Let me assure the reader that lithium-ion batteries are safe and heat related failures are rare. The battery manufacturers achieve this high reliability by adding three layers of protection. They are: [1] limiting the amount of active material to achieve a workable equilibrium of energy density and safety; [2] inclusion of various safety mechanisms within the cell; and [3] the addition of an electronic protection circuit in the battery pack.

These protection devices work in the following ways: The PTC device built into the cell acts as a protection to inhibit high current surges; the circuit interrupt device (CID) opens the electrical path if an excessively high charge voltage raises the internal cell pressure to 10 Bar (150 psi); and the safety vent allows a controlled release of gas in the event of a rapid increase in cell pressure.

In addition to the mechanical safeguards, the electronic protection circuit external to the cells opens a solid-state switch if the charge voltage of any cell reaches 4.30V. A fuse cuts the current flow if the skin temperature of the cell approaches 90°C (194°F). To prevent the Presario CQ43 brand new from over-discharging, the control circuit cuts off the current path at about 2.50V/cell. In some applications, the higher inherent safety of the spinel system permits the exclusion of the electric circuit. In such a case, the battery relies wholly on the protection devices that are built into the cell.

We need to keep in mind that these safety precautions are only effective if the mode of operation comes from the outside, such as with an electrical short or a faulty charger. Under normal circumstances, a lithium-ion battery will simply power down when a short circuit occurs. If, however, a defect is inherent to the electrochemical cell, such as in contamination caused by microscopic metal particles, this anomaly will go undetected. Nor can the safety circuit stop the disintegration once the cell is in thermal runaway mode. Nothing can stop it once triggered.

The high heat of the failing cell can propagate to the next cell

May 02 [Thu], 2013, 16:26
With the high usage of lithium-ion in cell phones, digital cameras and laptops, there are bound to be issues. A one-in-200,000 failure rate triggered a recall of almost six million lithium-ion packs used in laptops manufactured by Dell Presario C700 brand newand Apple. Heat related battery failures are taken very seriously and manufacturers chose a conservative approach. The decision to replace the batteries puts the consumer at ease and lawyers at bay. Let's now take a look at what's behind the recall.

Sony Energy Devices (Sony), the maker of the lithium-ion cells in question, says that on rare occasions microscopic metal particles may come into contact with other parts of the battery cell, leading to a short circuit within the cell. Although battery manufacturers strive to minimize the presence of metallic particles, complex assembly techniques make the elimination of all metallic dust nearly impossible.

A mild short will only cause an elevated self-discharge. Little heat is generated because the discharging energy is very low. If, however, enough microscopic metal particles converge on one spot, a major electrical short can develop and a sizable current will flow between the positive and negative plates. This causes the temperature to rise, leading to a thermal runaway, also referred to 'venting with flame.'

Lithium-ion cells with cobalt cathodes (same as the recalled laptop batteries) should never rise above 130°C (265°F). At 150°C (302°F) the cell becomes thermally unstable, a condition that can lead to a thermal runaway Presario CQ40 brand new in which flaming gases are vented.

During a thermal runaway, the high heat of the failing cell can propagate to the next cell, causing it to become thermally unstable as well. In some cases, a chain reaction occurs in which each cell disintegrates at its own timetable. A pack can get destroyed within a few short seconds or linger on for several hours as each cell is consumed one-by-one. To increase safety, packs are fitted with dividers to protect the failing cell from spreading to neighboring cells.

A mild short will only cause an elevated self-discharge

April 28 [Sun], 2013, 10:42
With the high usage of lithium-ion in cell phones, digital cameras and laptops, there are bound to be issues. A one-in-200,000 failure rate triggered a recall of almost six million lithium-ion packs used in laptops manufactured by Dell and Apple. Heat related battery failures are taken very seriously and manufacturers 586029-001 laptop batterychose a conservative approach. The decision to replace the batteries puts the consumer at ease and lawyers at bay. Let's now take a look at what's behind the recall.

Sony Energy Devices (Sony), the maker of the lithium-ion cells in question, says that on rare occasions microscopic metal particles may come into contact with other parts of the battery cell, leading to a short circuit within the cell. Although battery manufacturers strive to minimize the presence of metallic particles, complex assembly techniques make the elimination of all metallic dust nearly impossible.

A mild short will only cause an elevated self-discharge. Little heat is generated because the discharging energy is very low. If, however, enough microscopic metal particles converge on one spot, a major electrical short can develop and a sizable current will flow between the positive and negative plates. This causes the temperature to rise, leading to a thermal runaway, also referred to 'venting with flame.'

Lithium-ion cells with cobalt cathodes (same as the recalled laptop batteries) should never rise above 130°C (265°F). At 150°C (302°F) the cell becomes thermally unstable, a condition that can lead to a thermal runaway Pavilion G42 laptop battery in which flaming gases are vented.

During a thermal runaway, the high heat of the failing cell can propagate to the next cell, causing it to become thermally unstable as well. In some cases, a chain reaction occurs in which each cell disintegrates at its own timetable. A pack can get destroyed within a few short seconds or linger on for several hours as each cell is consumed one-by-one. To increase safety, packs are fitted with dividers to protect the failing cell from spreading to neighboring cells.

Airbus has design features intended to make the battery

April 28 [Sun], 2013, 10:32
Airbus CEO Fabrice Bregier does not see an imminent effect of the Boeing 787 grounding on the Airbus A350 program, which also plans 593562-001 laptop batteryto use lithium-ion batteries like those causing problems for Airbus’s U.S. rival.

Bregier during a Jan. 17 press conference said, “Airbus went through discussions with the FAA and the European Aviation Safety Agency about the electric architecture of the aircraft and they seemed very happy at the time.”

Airbus will “carefully study” recommendations that come out of the Boeing 787 investigation and evaluate whether they apply to the A350, with Bregier noting that the A350 still is in the development stage, so modifications are still possible.

However, Executive VP-Programs Tom Williams concedes that replacing the lithium-ion batteries would be a “very serious decision” and possibly cause “months in delays” in the A350 program.

The real impact on Airbus is still uncertain. While Airbus has selected a different supplier, Saft, for the batteries, the A350 also is a less electric aircraft than the 787. Systems such as braking and functions such as de-icing are still performed in the conventional way, using hydraulics and bleed air, respectively.

Williams also says Airbus is using more cells than Boeing in functions such as auxiliary power unit startup, where lithium-ion batteries are used. That leads to less power per battery being required. “But that does not mean that we may not be facing the same issues as Boeing,” he adds.

According to Williams, Airbus has design features intended to make the battery operation particularly safe, including mechanical relie 537627-001 laptop batteryf vents made of titanium. “The critical issue is to get failure management right,” he says.

Airbus could use nickel-cadmium batteries, but that would require a huge effort, and , says Williams says, would lead to a significant weight and space penalty. Also, nickel-cadmium batteries are prone to the memory effect and cannot be recharged fully after a certain number of cycles.

Batteries that do not pass the required tests

March 20 [Wed], 2013, 10:18
Emergency batteries that are connected to the bus are constantly in charge and thus continuously evaporate water from thereplacement U150 electrolyte. As the electrolyte level drops and the plate separator begins to be exposed (dried out in extreme cases), the separator material begins to deteriorate which results in cell heating and shorts in extreme cases.


Batteries that are subject to continuous charging and have little or no opportunity to deliver power, need to be removed periodically, first to check the water level and second to check for capacity.

Water level checking cannot be performed on the aircraft. It can only be performed under bench test conditions with a constant current charger and only when the battery has reached full charge. Excessive water consumption can be indicative of overcharging (bus voltage too high) or infrequent servicing, or both. The time required for this test will range from one day for a "good" battery to several days for a "problem battery".


Since emergency batteries are basically in stand-by condition and are subject to continuous charging, their capacity to deliver current when needed slowly diminishes (capacity fading), so it is also necessary to periodically perform a capacity test. If this test is passed marginally, or not at all, the cells have to be deep cycled (total discharge) to restore the rated capacity. Depending on the severity of the fading, the total discharge and subsequent recharge must be performed several times before proper capacity restoration will occur. The time required for this type of testing will require from two days for a "good" battery to a full week for a "problem" battery.

Batteries that do not pass the required tests can be repaired by replacing the individual cells that fail the specific tests, but not more than 20% of the total number of cells in the battery (4 to 5 cells) should be replaced. If more than 20% of the cells need to be replaced, the entire battery needs to be replaced (this is done to minimize the mismatching between new cells and old cells).

Under normal conditions, most batteries are expected to last five to six years, provided that they are serviced properly (Including occasional cell replacement). This is true even for the larger batteries that are used to start engines or APU’s. But, with improper maintenance (basically infrequent maintenance) the life of the batteries will be significantly shorter. If servicing is infrequent, by the time that thereplacement U160are finally removed for testing, it may be too late.


Proper servicing is costly. Time to do it, proper personnel, availability of a replacement battery, service charges by the battery shop, etc. But, if as a result of inadequate servicing the battery must be replaced, its cost far exceeds the cost of proper servicing. This is also true if a battery failure results in a grounded airplane. Finally, the cost of an in-flight battery failure (Overheating, little or no capacity to provide power, etc.) could have more severe consequences.

A good battery should be able to supply half

March 20 [Wed], 2013, 10:16

The condition of the cell plates inside the battery determines whether or not a battery is still serviceable. Current is produced when sulfuric acid in the battery reacts with lead in the cell plates. As the battery discharges, sulfate accumulates on the plates and reduces the battery's ability to make current. The sulfate replacement L08O6C02is returned to solution when the alternator recharges the battery by forcing current to flow in the opposite direction.

Over time, some of the sulfate becomes permanently attached to the plates. The sulfate forms a barrier that diminishes the battery's ability to produce and store electricity. This process can be accelerated if the battery is run down frequently or is allowed to remain in a discharged state for more than a few days. If the plates have become sulfated, therefore, the battery won't accept a charge and will have to be replaced.

Average battery life is only about four to five years under the best of circumstances -- and sometimes as short as two to three years in extremely hot climates such as Arizona and New Mexico. But the battery may become "sulfated" prematurely if it is chronically undercharged (charging problems or frequent short-trip driving), or if the water level inside the battery drops below the top of the cell plates as a result of hot weather or overcharging and allows the cell plates to dry out.


This is something you can't really do yourself, so you need to take your vehicle to a service facility that has the proper test equipment. The battery's condition can be determined one of two ways: with a carbon pile "load test" (that applies a calibrated load to the battery) or electronically with a special tester that measures the battery's internal resistance.

Equipment that uses a carbon pile for load testing requires the battery to be at least 75% charged. If the battery is less than 75% charged, a good battery may fail the test. So the state of charge must be checked first, and the replacement 43R1967recharged if it is low prior to testing. NOTE: The battery does NOT have to be fully charged prior to testing if an electronic tester that measures internal resistance is being used.

If load testing with a carbon pile, apply a load that is equal to half the battery's cold cranking amps (CCA) rating. A good battery should be able to supply half its CCA rating for fifteen seconds without dropping below 9.5 volts.

Li-ion battery packs are expensive

January 15 [Tue], 2013, 15:41
The scientists in South Korea believe their process will cut the time down to a matter of minutes—tackling head-on a key issue with rechargeable batteries, the time they take to recharge. Their method makes use of cathode material, standard lithium manganese oxide (LMO), soaked in a solution containing graphite. By carbonizing the graphite-soaked LMO, the graphite turns into a network of co battery for A32-F80 nductive traces that run throughout the cathode.

These carbonized graphite networks allow all parts of the battery to recharge at the same time. Therein lies the speed-up. The cathode is packaged with an electrolyte and graphite anode to create the fast-charging battery.

The key feature is that all energy-holding particles of the new battery start recharging simultaneously, in contrast to what takes place in conventional batteries, with the same particles recharging in order from the outermost particles to the innermost. Their work has been praised in its implications for hoped-for EV adoptions. “The development of such a battery could significantly raise the popularity of electric vehicles whose lithium-ion batteries currently take hours to recharge,” according to the Ministry of Education, Science and Technology.

Although electric vehicles promise more efficiency than gasoline and diesel-powered cars, the idea of spending two hours recharging a lithium ion battery has been seen as an inconvenience, and the time factor claimed by the scientists will obviously be seen with interest. All the same, cost will remain another barrier. According to observers, the time convenience does not address the pricetag inconvenience. Li-ion battery packs are expensive; the carbonized LMO battery developed by the researchers is not expected to carry a much lower price than what is available now.

The researchers’ paper, “Carbon-Coated Single-Crystal LiMn2O4 Nanoparticle Clusters as Cathode Material for High-Energy and High-Power Lithium-Ion Batteries,” was published earlier this month in Angewandte battery for A32-1015 Chemie. Authors are Sanghan Lee, Yonghyun Cho, Prof. Hyun-Kon Song, Prof. Kyu Tae Lee, and Prof. Jaephil Cho. The researchers were supported by the Converging Research Center Program through the Ministry of Education, Science and Technology.

The electrolyte is made of an organic solvent called dimethyl sulfoxide

January 15 [Tue], 2013, 15:38
The lithium air battery has long been over hyped — now add a pot of gold to the end of that rainbow. Scientific American reports that scientists at the University of Saint Andrews in Scotland have been using gold to make a battery for A32-UL20 prototype of a lithium air battery that has high energy density and lasts for a long time.

In a typical lithium ion battery, lithium ions travel from the cathode to the anode when you charge it (through the electrolyte), and the anode holds onto the lithium ions to store the energy. When you use a battery, the lithium ions move from the anode to the cathode and a resulting chemical reaction leads to the harvesting of the electrons. The anode and cathode are called the electrodes.

The scientists at Saint Andrews have been using gold to make a porous electrode that they say can create a lithium air battery that maintains almost all of its ability to hold a charge after 100 charging cycles. The battery also has high energy density, or amount of energy that the battery can hold for its size.

The problem with the life of batteries is that after a certain amount of charges — when ions are removed, sent over to the anode and then inserted back into the cathode — the structure of the battery starts to degrade. The crystal structure that holds the ions actually starts to change, as an ion from one spot doesn’t necessarily come back to that spot but could instead be inserted into another spot. In addition, traditional lithium ion batteries have a slurry made from an active material like lithium cobalt oxide held together with a glue-like binder. If the binder fails, the coating can peel off the current collector, and if the metal corrodes, it can’t move electrons as efficiently.



Lithium air batteries use air as the cathode and lithium metal as the anode. The scientists at University of Saint Andrews say using gold for part of the electrode provides a more stable substrate for the reaction between the air and the lithium. Their gold electrode also has tiny holes all over it — nano-porous — that provides room for the ions from the solid lithium peroxide. The electrolyte is made of an organic solvent called dimethyl sulfoxide.

The more energy dense a battery is, the less volume and weight is needed. For electric cars it is particularly important to have a high energy dense battery because electric cars need to be as lightweight as possible (any extra weight just drains the battery faster), and batteries that are smaller and use less materials can also be lower in cost.

The scientists at Saint Andrews say more work needs to be done to figure out why the experimental battery is providing such a high level of capacity and density. But they’re excited about the battery because it could provide a longer lasting electric car battery that has a bigger range than what’s currently battery for A32-K53 available. In an electric car, air that passes over the battery as the car drives, could be used for the cathode.

Clearly using lots of gold in a battery would be prohibitively expensive. One way to get around this would be to coat carbon with a gold plating. Other companies are working on the lithium air battery including IBM, and PolyPlus.