Laptops and other portable devices use coulomb counting for SoC

June 18 [Tue], 2013, 16:18
A critical concern among battery users is knowing “readiness” or how much energy a battery has at its disposal at any given moment. While installing a fuel gauge on a diesel engine is simple, estimating the energy reserve of a X130e replacementis more complex ― we still struggle to read state-of-charge (SoC) with reasonable accuracy.

Even if SoC were precise, this information alone has limited benefits without knowing the capacity, the storage capability of a battery. Battery readiness, or state-of-function (SoF), must also include internal resistance, or the “size of pipe” for energy delivery. Figure 1 illustrates the bond between capacity and internal resistance on hand of a fluid-filled container that is being eroded as part of aging; the tap symbolizing the energy delivery.

Most batteries for critical missions feature a monitoring system, and stationary batteries were one of the first to receive supervision in the form of voltage check of individual cells. Some systems also include cell temperature and current measurement. Knowing the voltage drop of each cell at a given load provides cell resistance. Elevated resistance hints to cell failure caused by plate separation, corrosion and other malfunctions. Battery management systems (BMS) are also used in medical equipment, military devices, as well as the electric vehicle.

Although BMS serves an important role in supervising of batteries, such systems often falls short of expectations and here is why. The BMS device is matched to a new battery and does not adjust well to aging. As the battery gets older, the accuracy goes down and in extreme cases the data becomes meaningless. Most BMS also lack bandwidth in that they only reveal anomalies once the battery performance has dropped to 70 percent. The all-important 70–100 percent operating range is difficult to gauge and the BMS gives the battery a good bill-of-health. This prevents end-of-life prediction in that the operator must wait for the battery to show signs of wear before making a judgment. These shortcomings are not an oversight by the manufacturers, and engineers are trying to overcome them. The problem boils down to technology, or the lack thereof. Over-expectation is common and the user is stunned when stranded with a dead battery. Let’s look how current systems work and examine new technologies.

The most simplistic method to determine end-of-battery-life is by applying a date stamp or observing cycle count. While this may work for military and medical instruments, such a routine is ill suited for commercial applications. A battery with less use has lower wear-and-tear than one in daily operation and to assure reliability of all batteries, the authorities may mandate that all batteries be replaced sooner. A system made to fit all sizes causes good batteries to be discarded too soon, leading to X200 replacementincreased operational costs and environment concerns.

Laptops and other portable devices use coulomb counting for SoC readout. The theory goes back 250 years when Charles-Augustin de Coulomb first established the “Coulomb Rule.” Coulomb counting works on the principle of measuring in- and out-flowing current of a battery. If, for example, a battery is charged for one hour at one ampere, the same energy should be available on discharge, but this is not the case. Internal losses and inaccuracies in capturing current flow add to an unwanted tracking error that must be corrected with periodic calibrations.

PNNL is at the forefront of proteomics and computational research directed

May 03 [Fri], 2013, 16:59
Biological systems science encompasses the ability to measure, predict, design, and ultimately control multi-cellular biological systems and bioinspired solutions for energy, environment, and health. It involves fundamental research and technology development using a systems and synthetic biology approach of natural X300 brand newand engineered biological systems both in the laboratory and in the field.

Pacific Northwest National Laboratory is recognized internationally for our biological systems science capabilities, including leadership in proteomics and other 'omic technologies, environmental microbiology, systems toxicology, and biotechnology. Our expertise also includes cell biology and biochemistry, radiation biology, computational biology and bioinformatics, bioforensics, and biodetection.

The biological systems science performed at PNNL contributes to advances in bioenergy, biogeochemistry of inorganic contaminants and carbon, human health, and national security.

Two areas in which PNNL is focused are biological dark matter and engineered biosystems.

Biological Dark Matter. Scientists can access an ever-increasing number of organisms for which the complete DNA sequence—the genome—is known. While genome sequencing reveals the basic building blocks of life, a genome U505 brand newsequence alone is insufficient for determining biological function.

"Unknown genes" are those for which the encoded function is unknown. These genes are part of what scientists refer to as "biological dark matter." PNNL is at the forefront of proteomics and computational research directed toward understanding biological dark matter.

The challenge in designing this material was water

May 03 [Fri], 2013, 16:58
Rechargeable lithium ion batteries, popular in cell phones, camcorders, and other devices, are based on the movement of a lithium ion—a lithium atom minus an electron. The lithium ion begins its journey attached to a metal X220i brand new cylinder or sheet, known as an electrode. The ion pushes off the electrode, moves through a liquid, and attaches itself to an electrode on the other side.

The ion's movement generates electricity, powering the battery. The researchers' new material, titanium dioxide crystals attached to a thin carbon sheet called graphene, is incorporated into the battery's negative electrode. The carbon/titanium material greatly improves the ion's ability to move in the electrode to provide a high capacity at high charge/discharge rate.

The challenge in designing this material was water. The researchers used water to reduce the cost of manufacturing. The precursors for the titanium dioxide crystals mixed well in water, easily dispersing. However, the graphene is hydrophobic or water fearing. Like oil or grease, it does not mix in water.

The solution? The active ingredient in many types of detergents: sodium dodecyl sulfate. This long, chain-like molecule contains a cluster of chemicals, or a head at one end, that mixes well with water. It has a long tail that grabs hold of hydrophobic materials. So, adding sodium dodecyl sulfate allows the graphene to evenly mix in the water with the precursors for the oxide crystals.

The sodium dodecyl sulfate not only solves the hydrophobic/hydrophilic incompatibility problem, it also provides a molecular template for the crystals to form and grow. Using the template, the titanium oxides form tiny crystals X220T brand newon the graphene sheets.

The researchers studied the resulting materials using transmission electron microscopy at the Department of Energy's EMSL, a national scientific user facility at PNNL. The resulting images showed the desired titanium dioxide crystals formed on the graphene sheets.

There would potentially be a diagnostic algorithm for aberrations

January 16 [Wed], 2013, 12:33
The devices could monitor biological activity in the ears of people with hearing or balance impairments, or responses to battery for AS10D51 therapies. Eventually, they might even deliver therapies themselves.

In experiments, Konstantina Stankovic, an otologic surgeon at MEEI, and HST graduate student Andrew Lysaght implanted electrodes in the biological batteries in guinea pigs’ ears. Attached to the electrodes were low-power electronic devices developed by MIT’s Microsystems Technology Laboratories (MTL). After the implantation, the guinea pigs responded normally to hearing tests, and the devices were able to wirelessly transmit data about the chemical conditions of the ear to an external receiver.

“In the past, people have thought that the space where the high potential is located is inaccessible for implantable devices, because potentially it’s very dangerous if you encroach on it,” Stankovic says. “We have known for 60 years that this battery exists and that it’s really important for normal hearing, but nobody has attempted to use this battery to power useful electronics.”

The ear converts a mechanical force — the vibration of the eardrum — into an electrochemical signal that can be processed by the brain; the biological battery is the source of that signal’s current. Located in the part of the ear called the cochlea, the battery chamber is divided by a membrane, some of whose cells are specialized to pump ions. An imbalance of potassium and sodium ions on opposite sides of the membrane, together with the particular arrangement of the pumps, creates an electrical voltage.

Although the voltage is the highest in the body (outside of individual cells, at least), it’s still very low. Moreover, in order not to disrupt hearing, a device powered by the biological battery can harvest only a small fraction of its power. Low-power chips, however, are precisely the area of expertise of Anantha Chandrakasan’s group at MTL.

The MTL researchers — Chandrakasan, who heads MIT’s Department of Electrical Engineering and Computer Science; his former graduate student Patrick Mercier, who’s now an assistant professor at the University of California at San Diego; and Saurav Bandyopadhyay, a graduate student in Chandrakasan’s group — equipped their chip with an ultralow-power radio transmitter: After all, an implantable medical monitor wouldn’t be much use if there were no way to retrieve its measurements.

But while the radio is much more efficient than those found in cellphones, it still couldn’t run directly on the biological battery. So the MTL chip also includes power-conversion circuitry — like that in the boxy converters at the ends of many electronic devices’ power cables — that gradually builds up charge in a capacitor. The voltage of the biological battery fluctuates, but it would take the control circuit somewhere between 40 seconds and four minutes to amass enough charge to power the radio. The frequency of the signal was thus itself an indication of the electrochemical properties of the inner ear.

To reduce its power consumption, the control circuit had to be drastically simplified, but like the radio, it still required a higher voltage than the biological battery could provide. Once the control circuit was up and running, it could drive itself; the problem was getting it up and running.

The MTL researchers solve that problem with a one-time burst of radio waves. “In the very beginning, we need to kick-start it,” Chandrakasan says. “Once we do that, we can be self-sustaining. The control runs off the output.”

Stankovic, who still maintains an affiliation with HST, and Lysaght implanted electrodes attached to the MTL chip on both sides of the membrane in the biological battery of each guinea pig’s ear. In the experiments, the chip itself remained outside the guinea pig’s body, but it’s small enough to nestle in the cavity of the middle ear.

Cliff Megerian, chairman of otolaryngology at Case Western Reserve University and University Hospitals Case Medical Center, says that he sees three possible applications of the researchers’ work: in cochlear implants, diagnostics and implantable hearing aids. “The fact that you can generate the power for a low voltage from the cochlea itself raises the possibility of using that as a power source to drive a cochlear implant,” Megerian says. “Imagine if we were able to measure that voltage in various disease states. There would potentially be a diagnostic algorithm for aberrations in that electrical output.”

“I’m not ready to say that the present iteration of this technology is ready,” Megerian cautions. But he adds that, “If we could tap into the natural power source of the cochlea, it could potentially be a driver behind the battery for Aspire 1410Tamplification technology of the future.”

The work was funded in part by the Focus Center Research Program, the National Institute on Deafness and Other Communication Disorders, and the Bertarelli Foundation.

Which makes lithium ion batteries for electric cars

January 16 [Wed], 2013, 12:31
The Obama administration provided struggling battery for AS07A71maker A123 Systems Inc with nearly $1 million on the day it filed for bankruptcy, the company told lawmakers investigating its government grant.

The company, which makes lithium ion batteries for electric cars, filed for Chapter 11 bankruptcy protection last month after a rescue deal with Chinese auto parts supplier Wanxiang Group fell apart.

That same day, October 16, A123 received a $946,830 payment as part of its $249 million clean energy grant from the Energy Department, the company said in a letter, obtained by Reuters, to Republican Senators John T battery for AS07B71hune and Chuck Grassley.
In the letter, dated November 14, A123 said the October payment was the most recent disbursement it had received from the government, with an additional $115.8 million still outstanding on the grant.

Thune and Grassley have pressed the Energy Department for more details about its funding of A123 as the company has faltered.
"The Department of Energy needs to answer for why it appears to put federal grants on auto-pilot to the detriment of U.S. taxpayers," the two senators said in a statement. "This can't stand."

A123 said it may still need to use the rest of its grant money if it decides to update or expand its current manufacturing capacity.
"The Energy Department takes its responsibility to be good stewards of the taxpayers' money very seriously," a department spokesman, Bill Gibbons, said in a statement.
Under the department's grant program, companies receive funds only after work is completed toward the ultimate goal of a grant.
Gibbons said the department's investments have helped to build U.S. advanced battery manufacturing, supported American workers and ensured the country can compete in a fiercely competitive global market.

Republicans on the campaign trail ahead of national elections earlier this month pointed to A123 as an example of failed clean energy investment from the Obama administration.
The Obama administration has defended its efforts, arguing that despite some high-profile bankruptcies, most of its investments have been successful and have helped to double renewable energy output from wind and solar.
The administration launched a stimulus-funded $2.4 billion initiative in 2009 to bolster U.S. advanced battery production, but the sector has struggled with overcapacity and weak demand for electric vehicles.

Thune and Grassley have also raised concerns about Chinese firm Wanxiang's attempts to acquire A123's battery business, saying military and taxpayer-funded technology should not be allowed to fall into foreign hands.
The Energy Department has stressed that none of the government's grant would be allowed to fund facilities abroad.
Wanxiang, one of the largest non-government-owned companies in China, is currently locked in a battle with U.S.-based Johnson Controls Inc to buy A123.
Wanxiang had attempted to bail out A123 prior to the company's filing for bankruptcy, but the $465 million deal collapsed when A123 was unable to meet some conditions of the agreement.

The senators questioned why the Energy Department continued to fund A123 even after it learned about the potential rescue deal. The company said it informed the department about the initial deal in early August.

A123 received several military contracts, including two worth a total of more than $4 million, to develop batteries for the Air Force.

In its letter to the senators, A123 confirmed it had received one federal government contract with a "secret" security classification.
The company said that it would expect the Committee on Foreign Investment in the United States (CFIUS) would lay out conditions to protect sensitive U.S. military data if the company is acquired by a foreign firm.

CFIUS is an interagency panel that vets foreign deals for security concerns.

The drawback is a higher price for the replacement battery

November 28 [Wed], 2012, 17:22
A major concern arises if static electricity or a faulty charger has destroyed the battery's protection circuit. Such damage can permanently fuse the solid-state switches in an ON position without the user knowing. A battery with a faulty protection circuit may function normally but does not provide protection against abuse.

Another safety issue is cold temperature charging. Consumer grade lithium-ion batteries cannot be charged below 0°C (32°F). Although the packs appear to be charging normally, plating of metallic lithium occurs on the anode while on a sub-freezing charge. The plating is permanent and cannot be removed. If done repeatedly, such damage can compromise the safety of the pack. The battery will become more vulnerable to failure if subjected to impact, crush or high rate charging.

Asia produces many non-brand replacement batteries that are popular with cell phone users because of low price. Many of these batteries don't provide the same high safety standard as the main brand equivalent. A wise shopper spends a little more and replaces the battery with an approved model. Figure 1 shows a cell phone that was destroyed while charging in a car. The owner believes that a no-name pack caused the destruction.

To prevent the infiltration of unsafe packs on the market, most manufacturers sell lithium-ion cells only to approved battery pack assemblers. The inclusion of an approved safety circuit is part of the purchasing requirement. This makes it difficult for a hobbyist to purchase single lithium-ion cells off-the-shelf in a store. The hobbyist will have no other choice than to revert to nickel-based batteries. I would caution against using an unidentified lithium-ion battery from an Asian source, if such cells is available.

The safety precaution is especially critical on larger batteries, such as laptop packs. The hazard is so much greater than on a small cell phone battery if something goes wrong. For this reason, many laptop manufacturers secure their 12 cells VGP-BPS13B/Q with a secret code that only the matching computer can access. This prevents non-brand-name batteries from flooding the market.

The drawback is a higher price for the replacement battery. Readers of often ask me for a source of cheap laptop batteries. I have to disappoint the shoppers by directing them to the original vendor for a brand name pack.

Considering the number of lithium-ion batteries used on the market, this energy storage system has caused little harm in terms of damage and personal injury. In spite of the good record, its safety is a hot topic that gets high media attention, even on a minor mishap. This caution is good for the consumer bright VGP-BPS13Sbecause we will be assured that this popular energy storage device is safe. After the recall of Dell and Apple laptop batteries, cell manufacturers will not only try packing more energy into the pack but will attempt to make it more bulletproof.

Squeezing every drop of juice out of a lithium ion battery

October 11 [Thu], 2012, 12:06
Longer battery life: Every laptop user wants it, but few know how to get it without buying a new machine. Though laptop manufacturers have made great strides over the past few years in increasing the efficiency (and thus the battery life) of their products, even the most efficient modern machines don't last long 9cells PA3537U-1BRSenough for many users.

What you may not realize, however, is that your system is probably loaded with integrated peripherals and bloatware that you'll never use but that consume resources and reduce battery life.

In this guide, we'll look at ways to reclaim those resources and maximize your laptop's battery life. Some of the steps may require venturing into the BIOS or UEFI of your notebook, while others are simpler software tweaks.

Know What Kills Your Battery
Before diving in, review why notebook batteries die in the first place. From the CPU to the trackpad, every component in a laptop consumes power. The amount consumed varies from component to component and also fluctuates in response to environmental conditions such as temperature and system workload. The greater the number of components or peripherals attached to your laptop and the more work you do with it, the quicker the battery will drain. Every program, driver, or service that loads, every background task that runs, and every electronic circuit that fires up saps a tiny bit of battery life. Consequently, reducing the number of attached or active peripherals and minimizing the load placed on the notebook will prolong battery life.

Unfortunately, some of the burdens that the manufacturer or vendor places by default on your laptop's battery may not be easy to track down and eliminate. As a result, you have to make an effort to minimize resource consumption and maximize battery life.

Try These Quick Fixes
PCWorld has posted simpler articles about how to extend your laptop battery life, and we won't cover the same items here. Keeping your laptop cool, dimming its display, and enabling system hibernation are all good ways to prolong battery life; but in this guide we'll be focusing on hard numbers that illustrate the potential benefits of certain modifications.Laptop batteries are like people--eventually and inevitably, they die. And like people, they don't obey Moore's Law--You can't expect next year's batteries to last twice as long as this year's. Battery technology may improve a bit over time (after all, there's plenty of financial incentive for better batteries), but, while interesting possibilities may pop up, don't expect major battery breakthroughs in the near future.

Although your battery will eventually die, proper care can put off the inevitable. Here's how to keep your laptop battery working for as long as possible. With luck, it could last until you need to replace that aging notebook (perhaps with a laptop having a longer battery life).
I've also included a few tips on keeping the battery going longer between charges, so you can work longer without AC power.

Don't Run It Down to Empty
Squeezing every drop of juice out of a lithium ion battery (the type used in today's laptops) strains and weakens it. Doing this once or twice won't kill the battery, but the cumulative effect of frequently emptying your battery will shorten its lifespan.

(There's actually an exception to this rule--a circumstance where you should run down the battery all the way. I'll get to that later.)

The good news: You probably can't run down the battery, anyway--at least not without going to a lot of trouble to do so. Most modern laptops are designed to shut down before the battery is empty.

In fact, Vista and Windows 7 come with a setting for just this purpose. To see it, click Start, type power, and select Power Options. Click any one of the Change plan settings links, then the Change advanced power settings link. In the resulting dialog box, scroll down to and expand the Battery option. Then expand Critical battery level. The setting will probably be about 5 percent, which is a good place to leave it.

XP has no such native setting, although rn873 PA3450U-1BRSyour laptop may have a vendor-supplied tool that does the same job.

Myth: You should never recharge your battery all the way.
There's considerable controversy on this point, and in researching this article I interviewed experts both for and against. But I've come down on the side of recharging all the way. The advantages of leaving home with a fully-charged battery--you can use your PC longer without AC power--are worth the slight risk of doing damage.

Falling just short of carrying an extra pack of batteries in the back-pack

October 11 [Thu], 2012, 12:04
Mobile computing has got better with lighter components, better chips and faster processors. But the Achilles heel of a laptop has remained its9cells PA3399U-2BAS. So here are we are going to look at ways to increase laptop battery life.

Modern graphic intensive operating systems and resource hungry applications are cutting down the life of your laptop’s battery every day. The average battery life per continuous use still stands at a maximum of three to four hours. So, a fast depleting battery could very swiftly put the crutches on your ‘mobile’ road trip.

Falling just short of carrying an extra pack of batteries in the back-pack, are several ways to keep the juice flowing through the batteries.

1. Ship shape with a defrag
Regular defragmentation helps to arrange data more efficiently thus making the hard drive work less to access the data. The quicker the moving hard drive works lesser is the load placed on the battery. Thus, your batter can last longer. The effect is minimal, but this efficiency goes hand in glove with hard drive maintenance.

2. Kill the resource gobblers
End the background processes that are not vital. Monitor the resource usage through a “?Ctrl-Alt-Del’ which brings up the Windows Task Manager (in Windows). If you’re not on the internet, it is safe to shut down the immediate high quality satellite PA3420U-1BRSnon-essential programs running in the taskbar like the antivirus and the firewall.

Weed out unnecessary programs running as start-ups by launching the System Configuration Utility from Run ““ Msconfig ““ Tab: Startup. Uncheck the programs which you don’t want to launch and reboot the computer once.

Counting cycle is not conclusive because a discharge may vary in depth

August 08 [Wed], 2012, 11:14
The lithium-ion battery works on ion movement between the positive and negative electrodes. In theory such a mechanism should work forever, but cycling, elevated temperature and aging decrease the performance over time. Since 9cells A1280are used in demanding environmental conditions, manufacturers take a conservative approach and specify the life of most Li-ion between 300 and 500 discharge/charge cycles.

Counting cycles is not conclusive because a discharge may vary in depth and there are no clearly defined standards of what constitutes a cycle. Read more about What Constitutes a Discharge Cycle?. In lieu of cycle count, some batteries in industrial instruments are date-stamped, but this method is not reliable either because it ignores environmental conditions. A battery may fail within the allotted time due to heavy use or unfavorable temperature conditions, but most quality packs will last considerably longer than what the stamp indicates.

The performance of a A1281 laptop battery is measured in capacity, a leading health indicator. Internal resistance and self-discharge also play a role but with modern Li-ion these carry lower significance in predicting the end-of-battery-life. Figure 1 illustrates the capacity drop of 11 Li-polymer batteries that have been cycled at a Cadex laboratory. The 1500mAh pouch cells for smartphones were first charged at a current of 1500mA (1C) to 4.20V/cell and allowed to saturate to 0.05C (75mA) as part of the full charge procedure. The batteries were then discharged at 1500mA to 3.0V/cell, and the cycle was repeated.