They were generally aimed at improving the regulations for the benefit of electric bikes so that they would no longer obstruct the development of the market. One of the amendments in particular was aimed at the exclusion from the type-approval of all electric pedal assisted cycles with assistance up to 25 km/h without specification of a motor output limit, because speed and not power is the determining safety factor.
A majority of IMCO members voted in favour of this exclusion. As a result, pedelecs with a motor output of more than 250 W would no longer have to be type-approved and would no longer be classified as mopeds but as bicycles. They would become subject to the Machinery and EMC Directive. This should result in a bigger offer and a wider usage for instance for people suffering from obesity, three-wheelers developed for physically impaired people, vehicles developed to transport cargo of for hilly areas etcetera.
The revision of the type approval for mopeds and motorcycles including electric bicycles caused controversy between industry associations COLIBI/COLIPED and the one for cyclists ECF on the one hand and trade association ETRA on the other hand. COLIBI/COLIPED and ECF wanted to make sure that the market remains limited to bicycles with pedal assistance up to 25 km/h and a motor output limit of 250W. Both industry organizations were in favour of maintaining the current specifications as described in the Directive 2002/24/EC.
“Terrific news,” said Annick Roetynck, ETRA general secretary on the breakthrough in ‘BOVAGkrant’, a publication of the Dutch dealer association BOVAG which is a prominent ETRA member. She continued: “We had to lobby hard for this result the past months. I am glad that the politicians understood that more powerful motors of which the assistance is limited to a speed of 25 km/h, do not jeopardize safety but instead greatly enhance the possible usage of electric bikes.”
As said 25 km/h pedelecs with more motor output are not a reality yet. In a plenary session  scheduled to take place in March 2012 the whole European Parliament will vote on it. Furthermore, the European Council, which is made up of the 27 member states also have to have a say on it.

All electrical devices come with charging and safety instructions which when followed will help prolong its life. Let us look at a few charging instructions of the lithium battery.

Technically, lithium-ion battery charging is in 3 stages:

1.    The charging current should be applied until each lithium cell reaches its voltage limit.

2.    The maximum voltage per cell limit is applied until the current reduces below 3% of rated charge current which is 1.

3.     Top-off charging should be applied once every 500 hours.

Stages 1 and 2 are entirely controlled by the charger and battery. Stage 3 is where you come in.

In simple terms, a lithium-ion battery should be charged for about three to five hours. This solely depends on the charger being used. The rated charge current is 1 and so batteries of cell phones can be charged at 1C and batteries for laptops at 0.8C. C here refers to the current that would discharge the battery in one hour. The battery charging is terminated when the current declines below 0.03C, which as stated in stage 2 is 3% of 1.

Whenever your battery voltage goes low (usually below 4.05 V/cell) and your phone starts beeping, it is recommended that you top-off charge the battery. 

Lithium-ion cells are usually charged with 4.2V with an allowed error of 0.05 V/cell. This simply means that the charging voltage can be either 4.25V or 4.15V. Make sure your battery voltage does not drop below 2.7-3.0V. If it does, your battery may become unchargeable. If a charging voltage of 4.3V is reached, charging is cut off.

These batteries come with charging manuals which contain the voltage and current ratings by the manufacturer. All specifications are usually given. If you want to prolong your battery life, it’s much safer to adhere to the instructions

The problem is, there’s no single price for electric car batteries. You can’t look it up on the Web or point your finger at a number in a catalogue. And that, of course, leaves the door open for some lively arguments.

Two weeks ago, three industry experts told us that they estimate today’s production EV battery costs to be between $800 and $1,000/kWh. When we printed those numbers, EV enthusiasts and backyard EV converters were quick to respond. “Lithium batteries today cost around $1 per Ah, so a 24 kWh pack like the Leaf equals approximately $7K if you buy cells as a private person,” wrote one commenter on a Design News blog last week. Assuming that the commenter was talking about a typical 3.5V EV battery, it would mean that the cost falls in the neighborhood of $285/kWh.

So here we have one group estimating today’s battery pack prices at $800 to $1,000/kWh, while another says, quite correctly, that EV cells are already available for $285/kWh.

How can there be such a disparity?

“There’s a reason why there’s such a big spread,” David Swan, founder of DHS Engineering, designer of the batteries for the 245mph White Lightning electric vehicle, and owner of three electric cars, told Design News. “It’s the difference between cells, battery packs, and the costs over vehicle life — things like warranties, profit, and return on development investment.”

There’s also another issue: The cost figures in today’s electric vehicles aren’t based on $1/Ah, off-the-shelf, lithium cells from China. Automakers typically contact suppliers, qualify their products, and form partnerships. Then they work with their partners to tweak battery chemistries to their specs. They balance power and energy. They test for quality and long-term reliability. This can take years, so the cell they use is in a different stage of development than the one that’s now available publicly. In other words: It’s better, it’s custom-engineered, and the price is different.

As Swan points out, however, the biggest disparity arises from the cost of cells versus the cost of an entire battery pack. Battery packs in production cars are different from those in backyard EV conversions. Automakers assemble their EV battery cells in a box with crash integrity. They also design elaborate cooling systems. The Chevy Volt employs a fluid coolant that circulates through 1mm-thick channels machined into 144 metal plates.

This is the cathode slurry mixing room. First ,we mix the powder with NMP in the mixing tank .And the NMP is added to the mixing tank in three times. Add more NMP to the mixing tank to adjust the slurry viscosity. Finally, transfer the slurry to the coating line after slurry sifting.

Anode slurry

This is the anode powder process. First, we mix CMC with water in that anode binder mixing room, and after weighing, the raw material is transferred into the mixing tank. Then, we add the anode binder solution to the mixing tank in 3 times. After that, we add the SBR for the final mixing. and then, we add more water to adjust the slurry viscosity. Next we sift the slurry in that sifting room. Finally, we transfer the finished slurry to the coating line.

Coating

Now, we are in coating line. We use back reverse coating. This is the slurry-mixing tank. The anode（Cathode） slurry is introduced to the coating header by pneumaticity from the mixing tank. The slurry is coated uniformly on the copper foil, then the solvent is evaporated in this oven. There are four temperature zones, they are independently controlled. Zone one sets at 55 degree C, zone two sets at 65 degree C, zone three sets at 80 degree C, zone four sets at 60 degree C. The speed of coating is 4 meters per minute.

You see the slurry is dried. The electrode is wound to be a big roll and put into the oven. The time is more than 2 hours and temperature is set at 60 degree C.

Throughout the coating, we use micrometer to measure the electrode thickness per about 15 minutes. We do this in order to keep the best consistency of the electrode.

Electrode

After coating we compress the electrode with this cylindering machine at about 7meters per minute. Before compress we clean the electrode with vacuum and brush to eliminate any particles. Then the compressed electrode is wound to a big roll. We use micrometer to measure the compressed electrode thickness every 10 minutes. After compressing we cut the web into large pieces. We tape the cathode edge to prevent any possible internal short. The large electrode with edge taped is slit into smaller pieces. This is ultrasonic process that aluminum tabs are welded onto cathodes using ultrasonic weld machine. We tape the weld section to prevent any possible internal short. And finally, we clean the finished electrodes with vacuum and brush.

Anode making

In anode making process, we cut the nickel roll into certain length strips. At the mean time, we put a small piece of insulation tape to the tab in order to prevent any possible internal short. Then the prepared nickel tab is riveted on anode and pat plain. We also tape the rivet section to prevent any possible internal short. And finally, we clean the finished electrodes with vacuum and brush.

Jelly roll

This is Jelly roll, a manual winding process. In the course of Jelly roll, firstly, we place the separator in between central pins, press the foot switch to turn central pins about 120 degrees. Secondly, place the anode to the edge of central pins, and turn central pins about 180 degrees. Lastly, place the cathode to the edge of central pins. During the winding process, we apply tension by pressing the electrodes and the separator. We put the termination tape at the end.

After Jelly roll, we check the short circuit, then form the Jelly roll by pressing, so that it is easier to insert the Jelly roll into the can.

Control points:

1. When winding to the end of the anode, covering the anode completely by the separator.

2. In the whole process, it is the most important points to ensure the best alignment among the cathode, the anode and the separator for the Jelly roll. The separator has to cover the anode and the cathode, and the anode has to cover the cathode completely. These points are mainly checked before short checking.

Taping&inserting

Put the tape on the two side of J/R, To prevent J/R being hurt in the insertion process.

Put a piece of tape between cathode tab and J/R .Because anode electrode is wider than cathode electrode.

Put the bottom tape.

Insert the finished J/R into the can manually and then short circuit check by multi-meter.

Spot welding Ni tab to cap.

Ultrasonic welding the Al tab to cap using ultrasonic weld.

We have the second spot welding to ensure the best contact between the tab and cap.

Apply top insulator, to prevent Ni tab contacting with can.

Final J/R insertion by the centrifuge.

Cap positioning by hand. Then check the cap in the suitable position, or the defects is put into red bin ,Finally , short circuit check again to ensure that there be no internal short J/R flowing to next line.

Laser welding

This is the Laser welding room! The first process is welding for the aluminum cap, specially connect the rivet with the weld plate to prevent the cell impedance excursion.

The second process is the Laser seam welding. In the process, it must ensure the intensity and airproof characters of the weld.

After the cell is welded, we would perform the leak checking, the short circuit checking and the weighing checking.

Oven drying electrolyte filling and storing

This is the process of cells oven drying at 80℃ for more than 12 hours under vacuum. After oven drying, the cells are transferred to the process of electrolyte filling through this channel. The electrolyte filling performs in dry room. The electrolyte is injected in two times so that it can be filled easily and sufficiently. When filling, vacuum first, then inject electrolyte. After that, we repeat vacuum and vent to room pressure several times. Finally the cell is put off at room pressure, then weigh the cell in order to check the amount of electrolyte. After weighing, we seal with tape onto the filling port to prevent the cells absorbing water during storing.

We store the filled cells for 24 hours at room temperature so that the electrolyte can be saturated sufficiently by the anodes and cathodes.

Pre-charge and ball seal

At first, we place a piece of absorb cotton above the filling port to absorb the excess electrolyte. This is the first process.

The second process is performing a pre-charge at 0.1C rate for 390 minutes.

After the pre-charge, we take a voltage checking to the cell at once. If the voltage is lower than the standard, it needs to be re-charged.

The fourth process is the ball seal. we must complete this process in 15 minutes.

First, put the steel ball in the right place. Then, give pressure to it so that the steel ball can fill the filling port.

In the whole process, we must make sure that the temperature and humidity are in the regular range.

Finally, the process is cleaning to eliminate the electrolyte on the cell surface with acetone solvent.

Aging and Formation

This is the aging room. We age cells at 35~40 Degree C for 7 days. The temperature is controlled by two heating instruments which are set at 38 Degree C. Then we transfer cells to the testing workshop. First, we check the voltage of cells with multi-meters. According to voltage, we divide the cells into acceptables and defects. Formation is done at 1.0 Capacity rate for 140 minutes to 4.2 Voltage. After that, check thickness and impedance. At last, we transfer the acceptables to the storehouse.

Most batteries, especially those for domestic devices have a metallic covering or outer case. The reason for this metal covering is because the battery is pressurized. The function of this metal case is just to let the battery let off some heat through its vent hole when it needs to. Being that these batteries will be used continuously, they could get pretty hot and run the risk of exploding. The metal case vent is simply a control agent to avoid the worst thing from happening.

This metal case consists of three tightly pressed sheets which are the positive electrode (cathode) made of Lithium cobalt oxide, the negative electrode (anode) which is made of carbon and the separator (electrolyte). The main element of this battery which is lithium has the ability to migrate through these electrodes.

During the charging process, lithium ions move from the positive electrode, pass through the electrolyte and to the negative electrode.During discharge process, the reverse is the case.

The lithium-ion movement is at a high voltage, thus producing 3.7 volts. This is double the amount of volts produced by normal AA alkaline cells and this makes lithium-ion batteries more compact and effective in small domestic devices like cell phones.

 1. Proper charging before use. All new batteries are always discharged when purchased and so they have to be fully charged before first use. Also note that in order for the battery to reach the maximum rated capacity, you’ll need to fully charge and discharge the new battery two to four times. This should be done before and not after using the battery for the first time.

 2. Utilize Your Battery. There is no point purchasing a battery and not using it for its sole purpose. It is not advisable to leave your battery dormant (i.e. without use) for a long period of time. Even if you do not use your power drill often, make use of it at least once in two or three weeks. This will prolong the life of the battery. What happens when you don’t use it during this time? Well, you can perform the first procedure to get your battery back on track. Charging your battery regularly will also help prevent the memory effect. You must charge and discharge your battery fully for at least once in two weeks. This only happens in the case of some batteries since Lithium-Ion batteries do not suffer from memory effect.

3. Clean the Batteries Regularly. Do not let your battery get dirty before cleaning. If you realize your battery contacts are dirty, clean them with alcohol or a cotton swab. This way, there will be good connection between the battery and device.

Most of us take our batteries for granted and don’t give them the treatment they deserve. Treat your battery well and it will serve you well.

Figure 1 illustrates the capacity drop of 11 Li-polymer batteries that have been cycled at a Cadex laboratory. The 1500mAh pouch cells were first charged to 4.20V/cell at 1C rate (1500mA) and allowed to saturate to 0.05C (75mA) as part of full charge procedure. The batteries were then discharged at 1500mA to 3.0V/cell, and the cycle was repeated.

Figure 1: Capacity drop as part of cycling. A pool of new 1500mA Li-ionbatteries for smart phone istested on a Cadex C7400 battery analyzer. All 11 pouch packs show a starting capacity of 88–94 percent and decrease in capacity to 73–84 percent after 250 full discharge cycles (2010).

Designed for a smart phone, the packs were already a few months old at time of testing and none of the batteries made it to 100 percent. It is common to see lower than specified capacities and shelf life may have contributed to this. Manufacturers tend to overrate their batteries; they know that very few customers would complain. In our test, the expected capacity loss was uniform over the 250 cycles. All sample batteries performed as expected.
Similar to a mechanical device that wears out faster with heavy use, so also does the depth of discharge (DoD) determine the cycle count. The smaller the depth of discharge, the longer the battery will last. If at all possible, avoid frequent full discharges and charge more often between uses. If full discharges cannot be avoided, try utilizing a larger battery. Partial discharge on Li-ion is fine; there is no memory and the battery does not need periodic full discharge cycles other than to calibrate the fuel gauge on a smart battery.
Specifying battery life by the number of discharge cycles is not complete by itself; equally if not more important are temperature conditions and charging voltages. Lithium-ion suffers stress when exposed to heat and kept at a high charge voltage.
Elevated temperature is anything that dwells above 30°C (86°F), and a high voltage is higher than 4.10V/cell. When estimating longevity, these conditions are difficult to assess because the battery state is in constant flux, and so is the temperature in which it operates. Exposing the battery to high temperature and being at full state-of-charge for an extended time can be more damaging than cycling. Manufacturers do not like to talk about these environmental conditions and release information only in confidence when so requested.
In this essay we do not depend on the manufacturer’s specifications alone but also listen to the comments of users. BatteryUniversity.com is an excellent sounding board to connect with the public and learn about reality. This approach might be unscientific, but it is genuine. When the critical mass speaks, the manufacturers listen. The voice of the multitude is in some ways stronger than laboratory tests performed in sheltered environments.
Let’s look at real-life situations and examine what stress a lithium-ion battery encounters. Most packs last three to five years, less if exposed to high heat and if kept at a full charge. Table 3 illustrates capacity loss as a function of temperature and state-of-charge. One can clearly see a performance drop of recoverable capacity caused by environmental conditions and not cycling. The worst condition is keeping a fully charged battery at elevated temperatures, which is the case when running a laptop on the power grid. Under these circumstances the battery will typically last for about two years, whether cycled or not. The pack does not die suddenly but will produce decreasing runtimes as part of aging.

Table 3: Permanent capacity loss of lithium?ion as a function of temperature and charge level. High charge levels and elevated temperatures hasten permanent capacity loss. Newer designs may show improved results.
Batteries are also exposed to elevated temperature when charging with wireless chargers. The energy transfer from a charging mat to the portable device is 70 to 80 percent and the remaining 20 to 30 percent is lost mostly in heat. Placing a cellular phone on the heat generating charging mat stresses the battery more than if charged on a designated charger. We keep in mind that the mat will cool down once the battery is fully charged. Read more: Charging without wires.
Equally stressful is leaving a battery in a hot car, especially if exposed to the sun. When not in use, store the battery in a cool place. For long-term storage, manufacturers recommend a 40 percent charge. This allows for some self-discharge while still retaining sufficient charge to keep the protection circuit active. Finding the ideal state-of-charge is not easy; this would require a discharge unit with an appropriate cut-off. Users should not worry too much about the state-of-charge; a cool and dry place is more important.
The voltage level to which the cells are charged also plays a role in extending longevity. For safety reasons, most lithium-ion cannot exceed 4.20V/cell. While a higher voltage would boost capacity, over-voltage shortens service life. Figure 4 demonstrates the increased capacity but shorter cycle life if Li-ion were allowed to exceed the 4.20V/cell limit. At 4.35V, the capacity would increase by 10 to 15 percent, but the cycle count would be cut in half. More critical than the extra capacity is reduced safety, which would be the results of a higher charge voltage.
Figure 4: Effects on cycle life at elevated charge voltages
Higher charge voltages boost capacity but lower cycle life and compromise safety.
Source: Choi et al. (2002)
Chargers for cellular phones, laptops and digital cameras bring the Li-ion battery to 4.20V/cell. This allows maximum runtime, and the consumer wants nothing less than optimal use of the battery capacity. The industry, on the other hand, is more concerned with longevity and prefers lower voltage thresholds. Satellites and electric vehicles are examples where longevity is important.
We have limited information by how much lower charge voltages prolong battery life; this depends on many conditions, as we have learned. What we do know, however, is the capacities. At a charge to 4.10V/cell, the battery holds a capacity that is about 10 percent less than going all the way to 4.20V/cell. In terms of optimal longevity, a charge voltage limit of 3.92V/cell works best but the capacity would be low. Besides selecting the best-suited voltage thresholds, it is also important that the battery does not stay in the high-voltage stage for a long time and is allowed to drop after full charge has been reached.
The voltage threshold of commercial chargers cannot be changed, and making it adjustable would have advantages, especially for laptops as a means of prolonging battery life. When running on extended AC mode, the user would select the “long life” mode and the battery would charge to only, say, 4.05V/cell. This would get a capacity of about 80 percent. Before traveling the user would apply the “full charge mode” to bring the charge to 4.20V/cell. This saturation charge would take about an hour and would fill the battery to 100 percent capacity.
Realizing the stress on the battery, some laptop and cellular phone manufacturers choose an end-of-charge voltage that is less than 4.20V/cell. A slightly larger pack compensates for the reduced runtime. Another option to extend battery life is removing the pack from the laptop when running on the power grid. The Consumer Product Safety Commissionadvises the public to do this out of concern for overheating and causing a fire. Removing the battery has the disadvantage of losing unsaved work on power failure.
Heat buildup is always a concern and running a laptop in bed or on a pillow may contribute to this by restricting airflow. Not only will heat stress electronic components, elevated temperature causes the electrodes in the battery to react with the electrolyte and this will permanently lower the capacity. Placing a ruler or other object under the laptop to increase floor clearance improves air circulation around the enclosure and keeps the unit cooler.
The question is often asked: Should I disconnect my laptop from the power grid when not in use? Under normal circumstances this should not be necessary because once the lithium-ion battery is full, a correctly functioning charger will discontinue the charge and will only engage when the battery voltage drops to a low level. Most users do not remove the AC power, and I like to believe that this practice is safe.
Everyone wants to keep the battery as long as possible and use it in a way that is least stressful. This is not always feasible. Sometimes we need to run the battery in environments that are not conducive to optimal service life. As a doctor cannot predict how long a person will live based on diet and activity alone, so also does the life of a battery vary, and it can always be cut short by an unexpected failure. Batteries and humans share the same volatility.
To get a better understanding of what causes irreversible capacity loss in Li-ion batteries, several research laboratories* are performing forensic tests. Scientist dissected failed batteries to find suspected problem areas on the electrodes. Examining an unrolled 1.5-meter-long strip (5 feet) of metal tape coated with oxide reveals that the finely structured nanomaterials have coarsened. Further studies revealed that the lithium ions responsible to shuttle electric charge between the electrodes had diminished on the cathode and had permanently settled on the anode. This results in the cathode having a lower lithium concentration than a new example, a phenomenon that is irreversible. Knowing the reason for such capacity loss might enable battery manufacturers to produce future batteries with longer life spans.
Power loss through Protection Circuit

Besides common aging, a Li-ion battery can also fail because of undercharge. This occurs if a Li-ion pack is stored in a discharged condition. Self-discharge gradually lowers the voltage of the already discharged battery and the protection circuit cuts off between 2.20 and 2.90V/cell. Some chargers and battery analyzers (including those from Cadex) provide a wake-up feature, or “boost,” to re-energize and recharge these seemingly dead Li-ion batteries.

*   Research is performed by the Center for Automotive Research at the Ohio State University in collaboration with Oak Ridge National Laboratory and the National Institute of Standards Technology.

Source: BatteryUniversity

The device comes with a specialized connector known as universal charger which can be used to charge practically all mobile phone brands like the Apple iPad, iPhone, Nokia, Sony Ericsson, Motorola and Samsung. This doesn’t exclude its capacity to charge your digital devices like laptops, notebook computers, MP3, PSP, digital camera or your PDA.

The mobile power bank was particularly designed for you to take along on business trips, meetings, camping expeditions, tours or just holidays. It will serve you well, especially if you need your digital devices almost all the time.

This power bank is slick, portable and can help you in a lot of ways. Where does this power come from? It simply comes from the power retained by Lithium ion battery after fully or partially charged.

Because of the lithium-ion battery built inside this mobile power one is sure of constant power for a period of time while on the move before recharging again. This device requires an input current based on the specification of the device and minimum voltage of DC 5.0V. It can be recharged through a USB connector or adaptor and can fully charge your mobile phone batteries 2-3 times. It also has an automated on/off technology which turns off charging your battery when your device is fully charged. This is just to prevent overcharging which in most cases damages the battery. It is simple, easy and doubles your battery life.

Like all electronic devices, this mobile power bank has its safety precautions. In order to extend the life of your power bank, you will need to charge it for its allocated time so as to prolong its life, keep it away from water or fire and use it for its specified function.

Purchasing a mobile power bank is a necessity, especially if you are the busy type and needs your mobile or digital device on the go. It will not only give your devices 24/7 power supply, it will also make them last longer and work better for you. Treat your power bank well and it will serve you well.