Tips for maximizing apple battery charge

Tips for maximizing apple battery charge

You can take some easy steps to prolong the charge of your Apple Macbook battery portable’s .

Here are some simple settings and steps you can take to get the most out of your MacBook, MacBook Pro 13 inch battery , MacBook Air, iBook G4 or PowerBook G4 battery.

Optimize your battery settings in Energy Saver preferences

1. From the Apple menu, choose System Preferences.
2. From the View menu, choose Energy Saver.
3. Click Show Details.
4. Choose Battery or Battery Power from the “Settings for” pop-up menu.
5. Choose Longest or Better Battery Life from the Optimize Energy Settings pop-up menu.

These settings will put the hard disk to sleep whenever possible and reduce the computer’s microprocessor performance in order to maximize its Apple A1175 battery life. If you are using processor-intensive applications, you may wish to change these settings so the microprocessor performance is no longer reduced.

Set your screen brightness to the lowest comfortable level

Press the F1 (dimmer) and F2 (brighter) keys to dim the screen until the brightness is as low as possible and the screen is still comfortable to look at.

Turn off unused features and technologies.

Just as you would turn off the lights in an unoccupied room, turning off unused features and technologies can help maximize your Apple A1185 battery life, too. Here are a few suggestions:

• Eject CDs and DVDs you’re no longer using. Every so often, the optical drive spins up to read CDs or DVDs. This consumes a small amount of power.
• Disconnect peripherals when you’re not using them. Connected peripherals, such as printers and digital cameras, can draw power from your Apple iBook G4 12 inch Battery even when you’re not using them.
• Shut down any runaway applications

If you’re not in a location where you need to use AirPort or Bluetooth, you can turn them off to save A1008 A1012 power.

To turn off AirPort:

1. From the Apple menu, choose System Preferences.
2. From the View menu, choose Network.
3. From the Show selection, choose Network Port Configuration.
4. Uncheck Airport from the list.
5. Click Apply Now.

To turn off Bluetooth in Mac OS X 10.2 or later in Apple A1057 A1060 :

1. From the Apple menu, choose System Preferences.
2. From the View menu, choose Bluetooth.
3. Click the Settings tab.
4. Click Turn Bluetooth Off.

Repair battery step one : calibrate your cell

Repair battery step one : calibrate your cell

First of all, the test voltage to zero, the machine can not start naturally, can not use power when charging (the battery light does not shine).

Disassemble the battery, more or less talk about the situation inside the battery.

Battery in a total of 9 can be placed 18 millimeters in diameter, length 65 mm core CGH18650 models the location of lithium batteries, Panasonic’s 22 batteries in parallel, three groups of series (OK, then my new Latitude D620 battery, the same, it appears that is 6), there is a very fine control with a single chip – the protection of the circuit, the circuit to the computer a total of five output contacts, respectively, are negative, the clock and data.

First of all, check the sticky in the battery temperature detection probe (temperature resistance), and temperature protection insurance, are also normal. Test-retest the battery voltage of each group, in which two sets of battery voltage of 3.8V, normal; a battery voltage of 0V, appear to have lapsed. The total battery voltage of 7.6V, then the failure of the battery pack has not yet open, then measuring the internal resistance was very small, almost in a state short-circuit.

First of all, failure to deal with Thinkpad T60 batteries, battery repair based on previous experience, the failure of the battery may not be completely damaged, can be activated through a number of methods, in particular the performance of state for the short-circuit the battery. The voltage of the battery to 0 with one end connected to the circuit board off line to avoid damage to circuit boards in operation. Open-circuit battery voltage after the re-survey, is still 0V, ruled out the possibility of short-circuit boards.

For short-circuit the battery failure, the method is more effective high-voltage electric current moment method, using the old IBM power supply (my back-up power), 16V maximum 3A output string on the multimeter (a tributary of the current file 20A), first negative power supply Even with the battery anode, and cathode power multimeter then red table pen, table pen with black multimeter battery cathode touch, speed, faster as far as possible, the former two degrees to see the multimeter has reached close to the 2A (moment) and the third on only 0.4 A about an immediate stop, measure the battery voltage has been restored to about 3V, the internal battery short-circuit that point has been an instant high-current boil (If you do not damage the battery to stop immediately, even if so, battery life and capacity have been the impact, if conditional, or recommend replacement, but if the replacement, then try to replace the entire battery pack are). However, the batteries need to be a separate charge (if the battery charge of the whole group, this will result in the other two groups had mesenchymal cells), plug in the charger to start charging ammeter to monitor during the charge current to 500mA or so, current for the 3.6AH battery pack is small, but the charger is the charge current is limited and a small current to the xps m1330 battery charge is good for the resumption. After about six hours, the charger showed the battery is already full, continue to re-charge for about two hours, remove the battery, measure voltage has reached 4.2V, with bright halogen bulb in the flashlight (3V, 500mA) to discharge its , bulb sharp discharge current of 700mA, the battery pack that has been basically restored, continue to discharge until the battery voltage down to 3.8V, the purpose of the two groups with the same battery voltage, charging time together so as not to overcharge the Back to the whole battery pack battery circuit welding.

Since the inspiron 6400 battery voltage while the circuit board there is no output, then, surely have damaged circuit boards, after observation, negative input circuit board (take battery) output (then output contact) is directly connected, and the positive input and output of by a high-power thyristor control, the thyristor remains cut-off state, that is, the control circuit has not been output control signals to the SCR control terminal, or simply the SCR has been destroyed. (Measured after the control signals that I did not) because I do not have the ability to repair single-chip microcomputer. IBM to take into account the protection of the BB more perfect, is about to run out of battery power will automatically shut down when, this battery is intended to be used for entertainment, therefore, need not be too concerned about, so I decided to shake the hp battery protection circuit, directly depend on BB’s protection circuit. SCR is in the input and output pin (that is, cathode circuit board input and output pin) between the solder on a small 2A fuse, fuse 2A select the reason is based on current usage, the largest in the computer power consumption , the current does not exceed 1.9A, 2A capacity sufficient unusual circumstances (for example, short-circuit accident) but also to ensure that the fuse of the time, but also play a role in protection.

In fact, directly to the SCR control terminal so that it can also be a high turn-on, but taking into account the current the battery must be a reason to burn, and the reasons for the identification of protective measures taken before or better in order to avoid greater loss.

Well, the battery power has been the first non-stick, and on the machine to try it! Normal boot, plug in the power immediately after the charge on the flashing lights are up, the way when charging the battery with a random look at battery information management software, was also displayed, the battery circuit board This shows that the single chip is still working.

Batteries battery is a Panasonic, the time the factory in June 2000, the first time in October 2000, the design capacity of 38.88Wh, the current capacity 38.88Wh, is charging cycle: 0 times.

Oh, do not know how to engage in, the inspiron 1300 battery may be burned when burning confused, even cycles to the zero, Now it maybe a new battery.

Repair battery step two : repair battery shell

Points and then encountered trouble: it was soon filling power (twice as fast than normal), in the course of discharge to 70% of the time will suddenly prompt “The battery is dead, please insert the AC power supply” warning capacity to show an immediate 5%. The beginning of a long time thought it was not using the battery leads to memory effect, we should do like a few of the deep cycle. But after several full charge, after release and found that the improvement is very small, only about 45 percent take power, with half an hour, we still have the problem. The largest may be the Inspiron 1520 battery pack in more than one section or “black sheep” in trouble, have to pull it out!

Red several times in the subsequent discharge cycle every place is full of electricity and have finished after the battery power to open, measuring the voltage of each battery pack to find a group of “different”: the per-charge when it voltage to reach 4.2V or even more than the first, leading to cessation of the entire VGP-BPS2 battery charge, and discharge when it was first to reach 3.6V or even less, is a typical decline in capacity. And the largest of which may still be a battery problem. This group of cells separated from the measurement of voltage, respectively, found that a battery voltage is low, only about 3.2V, a separate charge of their voltage quickly reach 4.2V, less than a minute of time, The A1185 battery basically has no capacity to speak with a light bulb when the discharge was found, it has the fundamental output current that can not provide even less than 1mA, measuring its resistance, has reached more than 2K seems to have been scrapped.
As a result of a “shock therapy” after the restoration of the normal cells, but not charging voltage reached 4.0V, it seems that it is “the pot boiled dumplings – do not put out an electric” soldering it back a battery discharge followed by the use of time of up to 90 minutes, has been near normal level of the battery.

However, when the charge is quickly filled, and disturbed mind up soon. Was a discharge, it is less than half an hour, open a test, just fix the bad and the battery.

Not always have to use a “heart to recover,” ah, so the value on the lost.

This section of the final decision to do a battery operation, and then they can not, then replaced the batteries. Peeling of the batteries, removed the insulation near the cathode cap and found a slight corrosion around, but I do not like battery leakage and traces, as well as save. With halogen lamp from the battery positive and negative, there is no response Taking into account the previous “Anatomy” the same symptoms when the batteries are inside the battery with the battery cathode output between cathode cap (the pressure on, not welded) oxide occurred, resulting in increased resistance and end-of-life battery , and the internal battery is still good. Oxide layer in the case is not serious as long as the battery cap to strengthen the internal contacts and battery resulting in the battery does not leak if damaged can be restored. The simplest way is to step up the battery forceps are negative (one pad insulation film), while measuring the inspiron E155 battery output voltage (or current), while vertical extrusion batteries, once the battery output voltage is increased, the current increase (the change is often the jumping in nature, relatively large changes) to stop immediately, the battery will be able to repair.
The top edge of the battery cathode cap next to the mouth ventilation valve with cutting pliers, then immediately measured and found that the battery has been restored, the output current increases immediately. In order to insurance purposes, the battery cap in the week between the edge of the chisel a few more in order to increase the contact area to ensure that the use of effects.

The battery to re-wrap, solder back to the XPS M1210 battery pack, charge, discharge. The use of time to reach more than 90 minutes.

Again measured with test software and found that the current capacity of smaller 38.88Wh from the original into a 32.07Wh, a decrease of nearly 20 percent, but this is the real discharge process, there is no jump of dropped. After several red discharge cycle, the capacity has increased by some. Use has been made to the current two months, everything will be all right.

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Dell inspiron 1520 battery review

Dell inspiron 1520 battery review

The update of Dell’s popular inspiron E1505 battery, the Inspiron 1520 has generated a lot of interest in the notebook community. It features a complete design update, the new Intel Santa Rosa platform, and the best graphics card Dell has ever offered in a laptop of this size.

The battery Inspiron 1520 is compatible with Dell notebooks including the Inspiron 1520, and replace the Dell battery code : 312-0518, 312-0589, 312-0590, 312-0594, 451-10477, fp282, gk479, nr239. This product comes with 1 year limited warranty.

The Dell inspiron 1520 battery Specs :

Battery Type: LI-ION
Technology : 6-cell lithium ion
Capacity: 49WH
Dimension: 201.2*47.1*20.3mm
Weight: 325g
Manufacturer Part# : FP282
Also work with : Dell Inspiron 1520 battery , Dell Inspiron 1521 battery , Dell Inspiron 1720 battery , Dell Inspiron 1721 battery , Dell Vostro 1500 battery , Dell Vostro 1700 battery

Effective laptop battery life under heavy processor load with high performance settings appears to be about three hours with the 9-cell battery. You could probably extend that to four hours or more by disabling wireless, turning down screen brightness, and using less intensive applications. The 9-cell battery does extend about 3/4” from the back of the laptop, but this does not seem especially noticeable given the already larger size of the notebook.

Customer Ratings :

So every year or so I’m expected to shell out ~$150 for a new inspiron 1520 battery? Mine stopped working shortly after one year. When I plug it in vista says “Battery 0%, NOT CHARGING” now, so I cannot use the laptop unless I am somewhere where I can plug it in. Great!
Not to mention it took almost 3 months for Dell to even ship this thing to me in the first place. I’ve been buying Dell computers for 10 years but not anymore

I used to have the 9-cell Dell 1520 battery before it had to be replaced, and the 6-cell doesn’t compare. The 9-cell lasted a lot longer without having to be recharged. Overall the battery is fair considering that it is the only one you can buy for the Inspiron 1520. It will last you for about a year, then be ready to buy a new one.

9Cell 80Whr Lithium Dell Latitude D830 Battery

9Cell 80Whr Lithium Dell Latitude D830 Battery

The Dell Latitude D830 is the successor to the Latitude D820 Battery, a mid sized business notebook with a 15.4″ screen and the new Santa Rosa platform. Weighing in at nearly six pounds it tips the scales at the upper end of the thin-and-light category.

Dell Latitude D830 battery specs:
Technology : 9-cell lithium ion
Capacity : 80 Wh
Manufacturer Part# : MM165
Dell Part# : 312-0538
Work With : Latitude D820 battery, Precision Mobile M4300, Dell Latitude D531

Dell Latitude D830 Battery is a Dell normal battery. You can power your laptop with this 9-Cell Lithium-Ion Primary Battery from Dell. With a capacity of up to 85 WHr Latitude D830 battery. This product comes with 1 year warranty. In my opinion it always can work about 1 year and 1 weeks long, just out of its quality warranty.

I did a simple test to emulate light use of the laptop under Dell D830 battery power. I turned the screen down to half brightness and let windows media player play music at a relatively low volume. This test was also done under the default Vista setup, prior to the installation of ForceWare drivers.
The 9-cell primary on its own reached 10% in a bit under three hours. Together with the media bay battery it reached 10% in just over four and a half hours.

Customer reviews:

Review:For the first year, the product will work well. Shortly thereafter, the Dell laptop battery life will not slowly decrease. Immediately you will notice a drastic fall in battery life to around five minutes. For battery performance, this is unacceptable. The warranty is only one year for a reason. Unless you plan to buy batteries annually (or thereabouts) i suggest buying another type of laptop. In all the Latitude D830 battery is "Easy to swap out – works like a champs".

The article Via laptop battery blog

Battery Type for difference use

Battery Type for difference use

Most traditional battery for electronic maintain a direction of movement to produce current, the laptop battery can be under the influence of the applied voltage is reflected in reverse occurs. Such as lead-acid batteries at the appropriate voltage to the battery charging, the two plates will be re-generated lead and lead dioxide. The secondary school had a lot of electrolytic hydrogen is generated during the reaction, hydrogen is difficult to return the electrolyte. Modern batteries use a variety of chemical substances to provide energy for the reaction.

A typical Dell laptop battery include: zinc-carbon batteries – (also known as the standard carbon batteries) all inexpensive AA-, C-and D-type zinc-carbon batteries are the use of chemicals. Electrode for zinc and carbon, using acidic paste between two poles liquid as the electrolyte. Alkaline batteries – used in common Duracell (duracell) and Energizer (Energizer) Digital Camera battery, the electrode for zinc and manganese dioxide, and use the alkaline electrolyte. Camera Lithium Battery – cameras use lithium batteries, lithium-iodide and lead iodide,

Because they can provide surge protection. Lead-acid batteries – used in cars, for lead and lead dioxide electrodes, and the use of strong acid electrolyte (rechargeable). Nickel-cadmium batteries – nickel hydroxide electrode and cadmium, and use potassium hydroxide as the electrolyte (rechargeable). Nickel-metal hydride batteries – these batteries will soon replace nickel-cadmium batteries, because the former there is no memory effect, while the latter exists (rechargeable).

Lithium-ion 40Y6797 Dell KD476 batteries – due to its excellent power-weight ratio, so that such batteries commonly used in high-end notebook computers and cell phones (rechargeable). Zinc-air batteries – these batteries, light weight, and can be charged. Zinc-mercury batteries – these batteries commonly used in hearing aids. Zinc-silver battery – due to have a good power-weight ratio, so that such batteries are used in aerospace equipment. Metal chloride batteries – these batteries are used in electric vehicles.

The use of VGP-BPS2C battery-powered devices because of the need for voltage and current are different, we can not only use a single cell, usually the Aspire One battery battery cell in series together to form higher voltages, or to parallel together to form a higher current.

Lithium-ion battery industry has become a hot competition in the field of new energy vehicles

Lithium-ion battery industry has become a hot competition in the field of new energy vehicles

Recently, Toyota Tsusho Corporation (hereinafter referred to Toyota Tsusho) and China CITIC Guoan Information Industry Company Limited (hereinafter referred to as CITIC Guoan) signed a letter of intent , the two sides will cooperate in production and sale of battery grade lithium 40Y6797 carbonate and downstream products. Toyota Tsusho is the Toyota Group in automotive related business trading company; CITIC Guoan is a subsidiary of CITIC Group’s listed companies, now has the West taijnar Qinghai Salt Lake, an area of 570 square kilometers, is a liquid lithium-based mining large deposits of lithium carbonate in resources highlighted Laptop battery. This is a new signal that the competition has been a new energy vehicles advance to the upstream resources.

Toyota’s success and vigorously promoted in recent years, hybrid cars are inseparable, but the auto industry’s future seems to depend on pure electric car market development. The current battery technology is not yet mature, and pure electric vehicles matching is not perfect, the market is not yet the same as the hybrid car is a vast market. To avoid risks, the world’s major automakers are seeking partners to develop new solutions.

Electric and hybrid cars are the hot new energy vehicle development, most auto makers have considered the use of lithium batteries as a power battery electric vehicles. Lithium-ion batteries due to a price and capacity advantages, is considered following the Ni-MH Lifebook T4220 battery power battery after the development direction of the world’s major manufacturers are all eager. Earlier this year the German government took out 500 million euros to finance research and development of electric vehicles. In which lithium-ion battery research and development funding cost of 59 million euros. Enacted in 2007, “high-tech strategy”, the German government has been the key technology of electric vehicles – lithium-ion batteries as tackling the project. Toyota had previously carried out in cooperation with Japan’s Sanyo Electric lithium-ion battery research and development, Honda, GM and other companies with the Panasonic, A123 and other battery vendors, China’s BYD Auto is also self-developed lithium-ion batteries, lithium-ion Dell laptop battery industry has been become the new competition in a hot area of energy vehicles.

The development of electric vehicles, battery technology is the core power technology of 40Y7001 40Y7003, but also determines the cost. The current of pure electric vehicles, battery-vehicle prices accounted for about 50% of the cost. According to industry optimistic forecasts that in the industrialization of pure electric vehicles, the battery-vehicle prices are still to be accounted for more than 20%, which is for the vehicle factory, is a very large, the profits pie.

Although the two sides reached a tentative co-operation only, but this shows that Toyota in the development of pure electric vehicles, not only wants to spread the risk of business cooperation with the upstream, more interested in sharing the upper reaches of the Sony PCGA-BP71 battery market profits. And this path, it may be the future of the automotive industry trends.

The development of electric vehicles, involving lithium VGP-BPS2C resources, lithium-ion batteries, electric motors and a series of product integration, as a pure electric vehicle market, the further development of possible future mergers and acquisitions Automotive Sony PCGA-BP2NX battery manufacturers trend.

The cooperation with CITIC Guoan, for Toyota, the ability to obtain a stable and sustainable sources of supply. Once the breakthrough in battery technology, lithium Toshiba PA3399U-1BRS resources will be more scarce resources. Access to reliable high-quality lithium resources will give Toyota a competitive edge in the future edge

The article is from battery talk

Principles of the battery

Principles of the battery

In the chemical cell, chemical energy directly into electricity through the laptop battery is carried out within the spontaneous oxidation, reduction and other chemical reactions the result of the reaction were carried out in two electrodes. Negative active material from the more negative potential and a stable reducing agent in the electrolyte composition, such as zinc, cadmium, lead active metals and hydrogen or hydrocarbons. Positive active material from a more positive potential in the electrolyte composition of a stable oxidizing agent, such as manganese dioxide, lead dioxide, Toshiba laptop battery, nickel oxide and other metal oxides, oxygen or air, halogens and their salts, oxygen-containing acid and its salts etc..

Electrolyte is a good ionic conductivity of the material, such as acids, alkali, salt solution, organic or inorganic non-aqueous solutions, molten salts or solid electrolytes. When the external circuit disconnected, although there potential difference between the two poles (open circuit voltage), but there is no current, stored in the Sony VGP-BPS9 batteries do not convert chemical energy into electrical energy. When the external circuit is closed, the two electrodes under the effect of potential difference that there is current flowing through the external circuit. The same time, the battery inside the electrolyte does not exist due to free electrons, charge transfer must be accompanied by two poles active material and Pavilion DV1000 battery electrolyte interface, the oxidation or reduction reactions, as well as reactants and reaction products of mass transfer.

Charge transfer in the electrolyte but also by the migration of ions to complete. Thus, within the normal Toshiba PA3451U-1BRS battery charge transfer and mass transfer process is to ensure that the necessary conditions for the normal output of electricity. When charging, the battery inside the transmission power and the direction of mass transfer and discharge exactly the opposite; electrode reaction must be reversible, in order to ensure the opposite direction of mass transfer and mass of the normal electrical Sony PCGA-BP2NX processes. Therefore, the electrode reaction reversible constitutes a necessary condition for batteries.

Reaction for the Gibbs free energy (coke); F is Faraday’s constant = 96500 base = 26.8 ampere-hour; n the equivalent number for the Latitude D600 battery cell reaction. This is the reaction of the battery and battery electromotive force between the basic thermodynamic relations, but also calculation of cell energy conversion efficiency of the basic thermodynamic equation. In fact, when the current flows through the electrodes, the electrode potential must deviate from the thermodynamic equilibrium of the electrode potential, a phenomenon known as polarization. Current density (unit electrode area adopted by the current), the greater the polarization more serious.

Polarization phenomenon is caused by the battery energy loss of the important reasons. Polarization for three reasons: ① from the IBM Thinkpad t60 battery cells caused by the various parts of the polarization resistance is called Ohm polarization; ② from the electrode – electrolyte interface layer caused by charge transfer blocked the process of polarization is called activation polarization; ③ from the electrode – electrolyte interface layer caused by slow mass transfer of polarization is called concentration polarization. Reduce the polarization method is to increase the electrode reaction area, reducing the current density, increasing reaction temperature and to improve the catalytic activity of the electrode surface.

The article Via Battery Talk

The secrets of battery runtime

The secrets of battery runtime

Is the runtime of a portable device directly related to the size of the laptop battery? The answer should be ‘yes’ but in reality, the runtime is governed by other attributes than the specified capacity alone.

This paper examines the cause of unexpected downtime and short battery service life. We look at four renegades – declining capacity, increasing internal resistance, elevated self-discharge and premature voltage cut-off on discharge. We evaluate how these regenerative deficiencies affect nickel, lead and lithium-based batteries. Declining capacity The amount of charge a laptop battery can hold gradually decreases due to usage and aging. Specified to deliver 100% capacity when new, the battery should be replaced when the capacity drops to below 80% of the nominal rating. Some organizations may use different end-capacities as a minimal acceptable performance threshold.

The energy storage of a battery can be divided into three imaginary sections consisting of: available energy, the empty zone that can be refilled, and the unusable part (rock content) that increases with aging. Figure 1 illustrates these three sections.

Figure 1: Dell laptop Battery charge capacity.Three imaginary sections of a battery consisting of available energy, empty zone and rock content.

In nickel-based batteries, the so-called rock content is present in form of crystalline formation, also known as memory. Restoration is possible with a full discharge to one volt per cell. However, if no service is done for four months and longer, a full repair becomes increasingly more difficult the longer service is withheld. To prevent memory, nickel-based batteries should be deep-cycled once every one or two months. Nickel-cadmium and nickel-metal-hydride batteries are used for two-way radios, medical instruments and power tools.

Performance degradation of the lead-acid battery is caused by sulfation and grid corrosion. Sulfation is a thin layer that forms on the negative cell plate if the battery is being denied a fully saturated charge. Sulfation can, in part, be corrected with cycling and/or topping charge. The Battery grid corrosion, which occurs on the positive plate, is caused by over-charge. Lead-acid batteries are used for larger portable devices and wheeled applications.

Lithium-ion Toshiba laptop batteries lose capacity through cell oxidation, a process that occurs naturally during use and aging. The typical life span of lithium-ion is 2-3 years under normal use. Cool storage a 40% charge minimizes aging. An aged lithium-ion cannot be restored with cycling. Lithium-ion is found in cell phones and mobile computing.

Increasing internal Resistance The capacity of a battery defines the stored energy – the internal resistance governs how much energy can be delivered at any given time. While a good battery is able to provide high current on demand, the voltage of a battery with elevated resistance collapses under a heavy load. Although the battery may hold sufficient capacity, the resulting voltage drop triggers the ‘low battery’ indicator and the equipment stops functioning. Heating the battery will momentarily increase the output by lowering the resistance.

A battery with high internal resistance may still perform adequately on a low current appliance such as a flashlight, portable CD player or wall clock. Digital Camera battery equipment, on the other hand, draw heavy current bursts. Figure 2 simulates low and high internal resistance with a free-flowing and restricted tap.

Figure 2: Effects of internal battery resistance.A battery with low internal resistance is able to provide high current on demand. With elevated resistance, the battery voltage collapses and the equipment cuts off.

Nickel-cadmium offers very low internal resistance and delivers high current on demand. In comparison, nickel-metal-hydride starts with a slightly higher resistance and the readings increase rapidly after 300 to 400 cycles.

Lithium-ion has a slightly higher internal resistance than nickel-based batteries. The cobalt system tends to increase the internal resistance as part of aging whereas the manganese (spinel) maintains the resistance throughout Apple laptop battery life but loses capacity through chemical reaction. Cobalt and manganese are used for the positive electrodes.

High internal resistance will eventually render the battery useless. The energy may still be present but can no longer be delivered. This condition is permanent and cannot be reversed with cycling. Cool storage at a partial state-of-charged (40%) retards the aging process.

The internal resistance of Lead-acid batteries is very low. The A1175 A1185 battery responds well to short current bursts but has difficulty providing a high, sustained load. Over time, the internal resistance increases through sulfation and grid corrosion.

Elevated self-discharge

All HP laptop batteries suffer from self-discharge, of which nickel-based batteries are among the highest. The loss is asymptotical, meaning that the self-discharge is highest right after charge and then levels off. nickel-based batteries lose 10% to 15% of their capacity in the first 24 hours after charge, then 10% to 15% per month afterwards. One of the best batteries in terms of self-discharge is Lead-acid; it only self-discharges 5% per month. Unfortunately, this chemistry has the lowest energy density and is ill suited for portable applications. lithium-ion self-discharges about 5% in the first 24 hours and 1-2% afterwards. Adding the protection circuit increases the discharge by another 3% per month. The protection circuit assures that the voltage and current on each cell does not exceed a safe limit. Figure 3 illustrates a battery with high self-discharge.

Figure 3: Effects of high load impedance.Self-discharge increases with age, high cycle count and elevated temperature. Discard a battery if the self-discharge reaches 30% in 24 hours.

The self-discharge on all battery chemistries increase at higher temperatures. Typically, the rate doubles with every 10°C (18°F). A noticeable energy loss occurs if a battery is left in a hot vehicle.

Aging and usage also affect self-discharge. nickel-metal-hydride is good for 300-400 cycles, whereas nickel-cadmium may last over 1000 cycles before high self-discharge affects the performance. An older nickel-based Sony laptop battery may lose its energy during the day through self-discharge rather than actual use. Discard a battery if the self-discharge reaches 30% in 24 hours.

Nothing can be done to reverse this deficiency. Factors that accelerate self-discharge are damaged separators induced by crystalline formation, allowing the packs to cook while charging, and high cycle count, which promotes swelling in the cell. Lead and lithium-based batteries do not increase the self-discharge with use in the same manner as their nickel-based cousins do. Premature voltage cut-off Not all stored battery power can be fully utilized. Some equipment cuts off before the designated end-of-discharge voltage is reached and precious battery energy remains unused. Applications demanding high current bursts push the battery voltage to an early cut-off. This is especially visible on iBook G4 battery with elevated internal resistance. The voltage recovers when the load is removed and the battery appears normal. Discharging such a battery on a moderate load with a battery analyzer to the respective end-of-discharge threshold will sometimes produce residual capacity readings of 30% and higher, jet the battery is inoperable in the equipment. Figure 4 illustrates high cut-off voltage.

Figure 4: Illustration of equipment with high cut-off voltage.Some portable devices do not utilize all available battery power and leave precious energy behind.

High internal battery resistance and the equipment itself are not the only cause of premature voltage cut-off – warm temperature also plays a role by lowering the battery voltage. Other reasons are shorted cells in a multi-cell battery pack and memory on nickel-based batteries.

The article is from http://www.batteryuniversity.com/

The New hair battery technology

The New hair battery technology

Researchers at the Universties of Miami, Tokyo and Tohoku have discovered a new form of laptop battery. Charged by the application of a very strong magnetic field, the Magnetic Tunnel Junction (MTJ) contains a set of nano-magnets – zones some 5 nanometers across in a zinc-gallium-arsenic-mangnesium matrix – which absorb energy and then release it over time. Although the effect had been predicted, the size and duration of the result was not “We had anticipated the effect, but the device produced a voltage over a hundred times too big and for tens of minutes Apple A1148 , rather than for milliseconds as we had expected,” said one of the researchers. “That this was counterintuitive is what lead to our theoretical understanding of what was really going on.”

The MJT is the top part of the illustration, and is roughly the same diameter as a human hair compare to Toshiba laptop battery. Beneath that is a magnified image of the central part of the device: the white spots are atoms, and the circles contain the nano-magnets that store the power. Picture: Phan Nam Hai/University of Miami

I’ve yet to dig out the paper in Nature to find out how far this is from being useful as a power source – as the current device is a few hundred micrometers across with IBM laptop battery, it’s not going to be storing megawatts. But it’s the sort of thing that could be created in vast arrays, like any semiconductor device, and if they’re getting to the bottom of the underlying physics then the same effect could be used in many different configurations of Thinkpad Z60T battery. What may be much more interesting than just power storage is the fact, mentioned almost in passing in the press release, that the current delivered by the MTJ is spin-polarised; the electrons are predominately spinning in one direction.

That’s hot news for spintronics, which we’ve covered previously and which, together with graphene, has the most exciting potential for fundamentally new computational devices. Spin logic could work much faster at much lower power than even today’s finest electronics Dell laptop battery, because it doesn’t rely on currents flowing and the consequent unavoidable loss.

And, as the researchers say, if this discovery leads to new insights into basic magnetic theory, there are almost no limits to how profoundly it could affect modern life with these Thinkpad R40 battery . Which is a bit over the top – just not that much.