Zinc-air batteries have similarities to the proton exchange  

July 03 [Wed], 2013, 12:05
Zinc-air batteries generate electrical power by an oxidation process of zinc and oxygen from the air. The cell can produce 1.65V, but 1.4V and lower achieves a longer lifetime. Removing a sealing tab activates the A1322 high quality y by enabling airflow and the battery reaches full operating voltage within five seconds. Once turned on, the battery cannot be stopped. Inhibiting airflow by adding a tape only slows degeneration.

Zinc-air batteries have similarities to the proton exchange membrane fuel cell (PEMFC) by using oxygen in the air as fuel for the positive electrode. Air can, to a certain extent, control the rate of the reaction. Zinc-air is considered a primary battery; however, there are recharging versions for high-power applications. Recharging occurs by replacing the spent zinc electrodes, which can be in the form of a zinc electrolyte paste. A different type of zinc-air battery uses zinc pellets. Rechargeable zinc-air batteries have been tried on electric vehicles and discontinued.

At 300–400Wh/kg, zinc-air has a high specific energy, manufacturing cost is moderate, but the specific power (current handling) is low. In a sealed state, the self-discharge is two percent per year. Zinc-air is sensitive to A1189 high quality extreme temperatures and high humidity. Pollution also affects performance; high ambient carbon dioxide reduces the performance by increasing the internal resistance. Typical applications are hearing aids and safety lamps at construction sites.

Lead acid with its many warts and blemishes 

July 03 [Wed], 2013, 12:04
Considering the importance which the battery holds in modern life, improvements have been slow in coming when compared to the advancements made in microelectronics. Let us not point the finger at laid-back scientists A1245 high quality and engineers but realize the complexity encountered. As long as the battery relies on the electrochemical process, limitations will continue. These are low energy storage, slow charging, short service life and high cost per watt.

Each battery system offers distinct advantages but none provides a fully satisfactory solution. For many years, nickel-based batteries delivered reasonably good service, but this chemistry is being superseded with lithium-ion offering higher specific energy (capacity), lower self-discharge and no maintenance. Lead acid with its many warts and blemishes still holds a solid position and will continue to keep its lead as starter and deep-cycle battery. No other system can meet the price and robustness on bulk power.

Never has there been so much activity in battery research and the electric vehicle (EV) is the catalyst for this frenzy. Expectations are high and the media is quick to announce a new battery that promises long runtime, good durability and is environmental friendly. Indeed, some systems show good potential, but most are years away from becoming commercially viable. Many disappear without a trace of the passing.

Typical failings of new battery concepts are weak load capabilities and short cycle life. Even a lemon can be made into a battery. Just poke a copper coin and galvanized nail into the innards. The power is low, and 500 lemons can light a flashlight bulb. Using seawater as an electrolyte has also been tried. The sea A1321 high quality would produce an endless supply of electricity, but the retrieved energy is only good to light a flashlight. Corrosion of the plates limits the useful service life and renders the seawater battery impracticable.

With the interest in battery developments at an all-time high, it is only fitting that we review old and up-and-coming systems. The chemistries listed below are placed in roughly the sequence of development. Many older batteries are being revised to offer longer lives, extended runtimes and better pricing.

The speed at which a battery can charge is limited  

May 14 [Tue], 2013, 16:27
Two researchers have developed battery cells that can charge up in less time than it takes to read the first two sentences of this article. The work could eventually produce ultra-fast power packs for everything from laptop Aspire 4810T brightcomputers to electric vehicles.

Byoungwoo Kang and Gerbrand Ceder of the Massachusetts Institute of Technology in Cambridge have found a way to get a common lithium compound to release and take up lithium ions in a matter of seconds. The compound, which is already used in the electrodes of some commercial lithium-ion batteries, might lead to laptop batteries capable of charging themselves in about a minute. The work appears in Nature1 this week.

Lithium-ion batteries are commonplace in everything from mobile phones to hybrid vehicles. "They're essentially devices that move lithium ions between electrodes," says Ceder. The batteries generate an electric current when lithium ions flow out from a storage electrode, float through an electrolyte, and are chemically bound inside the opposing cathode. To recharge the battery, the process is Aspire 4820T brightreversed: lithium ions are ripped from the cathode compound and sent back to be trapped in their anode store.

The speed at which a battery can charge is limited by how fast its electrons and ions can move - particularly through its electrodes. Researchers have boosted these rates by building electrodes from nanoparticle clumps, reshaping their surfaces, and using additives such as carbon. But for most lithium-ion batteries, powering up still takes hours: in part because the lithium ions, once generated, move sluggishly from the cathode material to the electrolyte.

Here is a brief summary of the most important characteristics 

April 03 [Wed], 2013, 12:35
Battery manufacturers are tooling up for the electric vehicle, but what would happen if it failed? Could there be a déjà vu of the fuel cell in the 1990s, or the bio fuels in the last decade that cannot survive without heavy government subsidies? The US Department of Energy (DOE) has admitted that some critical12 cells Studio 1535 parameters of Li-ion are not met. Newer NiMH batteries, which are cheaper and safer than Li-ion, are also suitable for the electric powertrain but these mature systems are often excluded from government grants for research.

There are no ideal contenders for the electric powertrain, and lithium-ion remains a good choice. Out of the five candidates illustrated in Figure 1, Li-nickel-manganese-cobalt (NMC), Li-phosphate and Li-manganese stand out as being superior. The popular Li-cobalt (not listed) used in consumer products was thought to be not robust enough; nevertheless, this high energy dense “computer battery” powers the Tesla Roadster and Smart Fortwo ED.


The illustration compares batteries in terms of safety; specific energy, also known as capacity; specific power, or the ability to deliver high current on demand; performance, the ability to function at hot and cold temperatures; life span, which includes the number of cycles delivered as well as calendar life; and finally cost. The figure does not mention charge times. All batteries offered for EV powertrains can be charged reasonably fast if a suitable electrical power outlet is available.

A charge time of a few hours is acceptable for most users, and super-fast charging is the exception. Nor does the table reveal self-discharge, another battery characteristic that needs scrutiny. In general, Li-ion batteries have low self-discharge, and this parameter can mostly be ignored when the battery is new. However, aging when exposed to heat pockets can increase the self-discharge of the affected cells and cause management problems. Among the EV battery candidates, Li-phosphate exhibits a higher self-discharge than the other systems.

None of the five battery candidates in the figure above show a significant advantage over others, and the size of the spider fields are similar in volume, although different in shape. Focusing on one strong attribute inevitably 12 cells Studio 1535discounts another. NCA, for example, has a high capacity but presents a safety challenge, whereas Li-phosphate is a safer system but has lower capacity.

In the absence of a clear winner, car manufacturers include peripherals to compensate for the deficiencies. Battery manufacturers in turn assist by custom-designing the cell to strengthen the important characteristics needed for the application. Here is a brief summary of the most important characteristics of a battery for the electric powertrain.

Q-Mag can be made small and sandwiched between cells 

April 03 [Wed], 2013, 12:32
Battery voltage, current and temperature alone are not sufficient to provide accurate SoC estimations, much less state-of-health (SoH). Early Li-ion correlated the rising internal resistance with SoH. This no longer works because12 cells T116C most modern Li-ion batteries maintain low resistance as the battery ages.

When designing a BMS, one also must consider how the battery serves the host. In an iPhone and most EVs, for example, the battery is “married” to the host. This enables collecting data for learning. The battery and device co-habitat in a similar way to partners in a good marriage. Batteries for two-way radio, on the other hand, are picked from a common charger and returned to a pool for recharging after use. Learning is difficult and a different method must be used to track battery health.

Cadex Electronics is making critical progress in measuring battery SoC with magnetism. Quantum magnetism (Q-Mag?) could provide the most accurate battery SoC readings ever achieved. Q-Mag? makes use of the magnetic property relating to SoC, which changes as much as three-fold between empty and full charge on some battery systems. A coil generates an AC field and a sensor reads the magnetic susceptibility, which is linear to SoC.

There are several choices of sensors and because of availability and low price Cadex conducts the research with the GMR (Giant Magnetoresistance) sensor. It consists of ferromagnetic alloys that are sandwiched on an ultrathin nonmagnetic conducting layer. Applying a magnetic field lowers the resistance; removing the force increases it. The principle is known as electron scattering, which is also used on hard drive read/write heads. Figure 2 illustrates the function of a GMR sensor.

Q-Mag? has successfully been tested with Li-ion-cobalt, NMC, lithium iron phosphate, as well as several types of lead acid batteries. The system is immune to most outside interference and does not rely on voltage for SoC estimations. This allows reading SoC while the battery is on charge or a load. Q-Mag? works with prismatic and cylindrical cells in aluminum and stainless steel casings, but not in ferrous material. The accuracy on lithium-based chemistries is +/-5%, lead acid is +/-7%. This high accuracy should be retained as the battery ages. Calibration occurs by applying a full charge.

With voltage and current references, Q-Mag? is able to calculate SoC and SoH. The BMS can also detect micro-shorts by observing the self-discharge of a faulty cell, a feature that enhances battery safety. Furthermore, Q-Mag? can be used for load leveling. This eliminates the rubber-band effect that complicates SoC12 cells Vostro 1720 estimations through voltage. Figure 3 shows Q-Mag as key contributor to BMS.


Q-Mag can be made small and sandwiched between cells. A multi-cell battery may have one sensor for an overall assessment or several to enable diagnostics to cell level. An ASIC containing Q-Mag? could also include temperature sensing and digital processing. At high volume, low price would make this technology available for big and small batteries, including consumer products. Displaying precise energy reserve, as is possible with a liquid fuel system, may be closer than we think.

What Consumers Should Do With Battery Life Numbers 

January 30 [Wed], 2013, 10:46
Here at the About.com PC Hardware / Reviews site, I do not use the MobileMark application or the various tricks that the manufacturers may use to get their various numbers for advertising. Instead, I use a video playback test on all laptops and using the default power profiles and software settings that a laptop cheap A1321ships with. For laptops with a DVD compatible drive, this entails playing back a standard DVD movie in a loop until the system shuts down. On laptops without a DVD drive, in entails playing back a Quicktime based video loop until the system shuts down. This in my opinion gives some of the best real world usage numbers available.

In general, these tasks are some of the toughest when it comes to power consumption. Typically, such a test will result in anywhere from 50 to 75% of the manufacturers claim of battery life. Of course, this is just one method of testing. People use their laptops in various ways and will generally get more battery life than this type of test but still below the manufacturer numbers.

What Consumers Should Do With Battery Life Numbers

Any consumer who is presented by a battery life number from any company or sales person needs to take this number and modify it to get a better idea of just how much battery life they would get. To determine this, you should really consider whether you use your computer heavily or lightly. A heavy user is someone that runs applications such as video editing, PC gaming or a large number of simultaneous applications. Light users are ones that typically only have one or two applications open at a time, use it primarily to browse the web or use productivity software.

Once you have determined the type of user you are, it is best to half the number if you are heavy users and subtract about one quarter if you are light user. For example, a four hour battery life claim will net roughly two cheap A1322 hours of use for a heavy uses and about three hours from a light user. This is just an estimate because it is very difficult to determine how long a battery will run on a laptop until it is used in your typical fashion.

This is one of the more consistent battery drawing tasks 

January 30 [Wed], 2013, 10:45
There are to things that will be the basis for determining how long a laptop computer should run on batteries. Of course, the overall capacity of the battery is the easiest to determine and understand. All batteries can store a fixed amount of energy in them. This is rated in mAh or milliampere-hours. I could go into cheap A1309 technical details but suffice to say, the higher the mAh that a battery is rated out, the more energy that is stored in the battery.

So, why is the battery capacity important? Of two systems that use the same amount of power, the one with a higher mAh rated battery will last longer. This makes comparison easy for the batteries themselves. The problem is that no two laptop configurations will draw the same amount of power.

Power consumption of a laptop depends upon all of the components that make up the system. So, a system with a lower power consumption CPU will generally last longer if all parts are equal but they almost never are. It gets even more complicated because the power consumption can also vary depending upon how the laptop is being used. Heavy disk uses draws more power than little usage.

All isn't lost for consumers though. In general the size of the laptop will also equate to how much power it uses. For example, a desktop replacement will generally draw more power than a thin and light. A thin and light draws more power than an ultraportable and a netbook draws even less still.

Manufacturer Claims

Now that the basics are out of the way, how can a manufacturer come up with a claim of something like ten hours of running time for a laptop yet a user in real world use may get only half as much time? It all has to do with how the manufacturers conduct their battery life tests. The most common of these is a function of the MobileMark benchmarking suite from BapCo. It simulates computer usage through sampled application use via programs such as Quicktime, Photoshop, Flash, Office and WinZip.

Now, this is a valid test that simulates usage, but it is how the test simulates usage. The test generally has the CPU idle during much of the test on the basis that many people are either idle or their applications are awaiting user input. It also doesn't set various power settings within the OS. Manufacturers often use various tricks such as decreasing the display brightness to the lowest levels and turning all of the battery saving features to their maximum the running time so they can get the cheap A1245 highest run times possible.

The problem is that this is not how people use their laptops in real life. A good example is people who use their laptops for viewing DVDs on an airplane flight. This is one of the more consistent battery drawing tasks that one can use on their laptop. Thus, a battery life claim of four hours might net just two hours of DVD viewing.

Lithium-ion has been tested for two-way radios  

December 12 [Wed], 2012, 16:11
Most two-way radios use nickel-cadmium. These batteries are durable and forgiving if abused. But nickel-cadmium batteries have only moderate energy density and are environmentally unfriendly. Environmental agencies have been discouraging its use, especially in Europe. The recommended alternative is nickel-metal-hydride, aRechargeable UM09A41that has higher energy density and contains no toxic metals. nickel-metal-hydride has been tested in two-way radios for a number of years but the results are mixed. Shorter than expected service life is the major drawback.

For two-way radios, nickel-metal-hydride has a cycle life, which is half that of standard nickel-cadmium. Nickel-metal-hydride prefers a moderate discharge current of 0.5C or less. A two-way radio, on the other hand, draws a discharge current of about 1.5A when transmitting at 4W of power. High discharge loads and sharp pulse currents shorten battery life.

To compare the longevity of nickel-metal-hydride under different load condition, a test was carried out in which batteries of the same type were discharged with a DC and digital load. In both tests, the batteries were discharged to 1.04 volts per cell. The DC load was a steady 500mA; the digital load simulated the Global System for Mobile Communications (GSM) at 1.65 ampere peak for 12 ms every 100 ms with 270 mA standby. (Note that the GSM pulse for voice is about 550 ms every 4.5 ms).

With the DC discharge, nickel-metal-hydride wore out gradually, providing an above average service life. At 700 cycles, the battery still provided 80% capacity. By contrast, the same battery type faded more rapidly with a digital discharge and the 80% capacity threshold was reached after only 300 cycles. This phenomenon indicates that the kinetic characteristics for nickel-metal-hydride deteriorate more rapidly with a digital than analog load. Although the test was simulating a GSM cell phone, Tetra and other digital two-way radios have similar loading.

Let's briefly compare the characteristics of nickel-cadmium and nickel-metal-hydride. nickel-cadmium has the advantage of maintaining steady high capacity and low internal resistance through most of its service life. nickel-metal-hydride, on the other hand, starts with good capacity and low internal resistance but the resistance increases after a few hundred cycles, causing the voltage to drop on a load. Even though the energy may still be present, the battery cannot deliver the high current during transmit and the message cuts off. The radio becomes unreliable.

Nickel-based batteries are high in maintenance. Periodic discharge cycles are needed to prevent crystalline formation on the cell plates, also known as memory. Nickel-cadmium is more receptive to memory than nickel-metal-hydride because both nickel and cadmium plates are affected by memory.

Nickel-cadmium should be exercised once ever 1 to 2 months, whereas nickel-metal-hydride can get by with a deliberate full discharge once every 3 months. Without proper maintenance, the advantage of nickel-cadmium OEM UM09A75over nickel-metal-hydride in terms of cycle life cannot be realized.

Lithium-ion has been tested for two-way radios and the results are positive. Substituting lithium-ion with nickel-based will require chargers specifically suited for this chemistry. While nickel-cadmium and nickel-metal-hydride can often share the same charger, lithium-ion uses a different charge algorithm. There is also a cost premium for lithium-ion. Future two-way radios will undoubtedly be fitted with lithium-ion.

Lithium-ion gradually loses charge acceptance  

December 12 [Wed], 2012, 16:06
Early cell phones were powered with nickel-based batteries but most newer phones are now equipped with lithium-ion. This chemistry is lightweight, offers high energy density and lasts long enough to span the typical life oEarly cell phones were powered with nickel-based batteries but most newer phones are now compatible AS10D61 equipped with lithium-ion. This chemistry is lightweight, offers high energy density and lasts long enough to span the typical life of the product. Lithium-ion contains no toxic metals.

To obtain thin geometry, some cell phone manufacturers switched to lithium-ion-polymer.

This satisfied consumer requests for slim designs. In the meantime, technological advancements also made low profile lithium-ion possible. lithium-ion packs are now available in 3 mm, a profile that suits most designs. lithium-ion has the advantage of lower manufacturing cost, better performance and longer cycle life than the polymer version.

Lithium-ion is a low maintenance battery. No periodic discharge is needed and charging can be done at random. A random charge means that the battery does not need to be fully depleted before recharge. In fact, it is better to recharge before the battery gets too low. Full discharges put an unnecessary strain on the battery. A recharge on a partially charged battery does not cause memory because there is none.

Charging lithium-ion is simpler and cleaner than nickel-based batteries but the chargers require tighter tolerances. Lithium-ion cannot absorb overcharge and no trickle charge is applied on full charge. This allows lithium-ion to be kept in the chargers until used. Some chargers apply a topping charge every week or so to replenish the capacity lost through self-discharge while the battery sits idle in the charger. Repeated insertion into the charger or cradle does not damage the battery though overcharge. If the battery is full, no charge is applied. The battery voltage determines the need to charge.

On the negative side, lithium-ion gradually loses charge acceptance as part of aging, even if not used. lithium-ion batteries should not be stored for long periods but be rotated like perishable food. The buyer should be aware of the manufacturing date when purchasing a replacement battery. Aging affects battery chemistries at different degrees.f the product. Lithium-ion contains no toxic metals.
To obtain thin geometry, some cell phone manufacturers switched to lithium-ion-polymer.

This satisfied consumer requests for slim designs. In the meantime, technological advancements also made low profile lithium-ion possible. lithium-ion packs are now available in 3 mm, a profile that suits most designs. lithium-ion has the advantage of lower manufacturing cost, better performance and longer cycle life than the polymer version.

Lithium-ion is a low maintenance battery. No periodic discharge is needed and charging can be done at random. A random charge means that the battery does not need to be fully depleted before recharge. In fact, it is better to recharge before the battery gets too low. Full discharges put an unnecessary strain on the battery. A recharge on a partially charged battery does not cause memory because there is none.

Charging lithium-ion is simpler and cleaner than nickel-based batteries but the chargers require tighter tolerances. Lithium-ion cannot absorb overcharge and no trickle charge is applied on full charge. This allows lithium-ion to be kept in the chargers until used. Some chargers apply a topping charge every week or so to replenish the capacity lost through self-discharge while the battery sits idle in the charger. Repeated insertion into the charger or cradle does not damage the Original UM09A31though overcharge. If the battery is full, no charge is applied. The battery voltage determines the need to charge.

On the negative side, lithium-ion gradually loses charge acceptance as part of aging, even if not used. lithium-ion batteries should not be stored for long periods but be rotated like perishable food. The buyer should be aware of the manufacturing date when purchasing a replacement battery. Aging affects battery chemistries at different degrees.

There are several types of 'smart' batteries 

October 23 [Tue], 2012, 12:21
The battery has the inherit problem of not being able to communicate with the user. Neither weight, color, nor size provides an indication of the 9cells PA3399U-2BAS state-of-charge (SoC) and state-of-health (SoH). The user is at the mercy of the battery.

Help is at hand in breaking the code of silence. An increasing number of today's rechargeable batteries are made 'smart'. Equipped with a microchip, these batteries are able to communicate with the charger and user alike. Typical applications for 'smart' batteries are notebook computers and video cameras. Increasingly, these batteries are also used in biomedical devices and defense applications.

There are several types of 'smart' batteries, each offering different complexities and costs. The most basic 'smart' battery may contain nothing more than a chip that sets the charger to the correct charge algorithm. In the eyes of the Smarthigh quality satellite PA3420U-1BRSSystem (SBS) forum, these batteries cannot be called 'smart'.

What then makes a battery 'smart'? Definitions still vary among organizations and manufacturers. The SBS forum states that a 'smart' battery must be able to provide SoC indications. In 1990, Benchmarq was the first company to commercialize the concept by offering fuel gauge technology. Today, several manufacturers produce such chips. They range from the single wire system, to the two-wire system to the System Management Bus (SMBus). Let's first look at the single wire system.