Category: Battery Technology

What Raw Minerals Are Used To Make a Battery?

To build a battery you have four basic overarching battery components including the casing, chemistry, electrolyte, and the internal specialized hardware. At the core of these four basic overarching battery components are the foundation blocks; the raw materials necessary for the construction of a battery. Minerals and materials used in the construction of batteries are numerous but the core mineral required to have a battery is the batteries chemical which can either be : cadmium, cobalt, lead, lithium, and nickel (along with other rare earth elements).  Why is the chemical one of the most important element in a battery: because a battery at its most basic element is a system that converts and stores electrochemical energy for the purpose of providing portable power to a device. Without the chemistry changing chemical energy into electrical energy is impossible. So needless to say the availability of minerals used in batteries are highly important!

Incidentally the available raw material supply and price often times dictates how much your battery is going to be – if the raw material price is higher, than, your battery cost will be higher (the converse of that is also true). But what are the current supplies of the battery making minerals and how much demand is out there for these minerals?

In the United States there are currently 6,841 different mining operations ranging from aluminum to zircon.  Although 6,841 mines sounds like a lot of mining operations you must evaluate that number against the total demand of minerals. Consider that every American born in 2007 is estimated to use the following amounts of nonfuel mineral commodities over their lifetime (data pulled from MII):

  • Aluminum (bauxite) 5,677 pounds
  • Cement 65,480 pounds
  • Clays 19,245 pounds
  • Copper 1,309 pounds 
  • Gold 1,576 ounces
  • Iron ore  29,608 pounds
  • Lead 928 pounds
  • Phosphate rock  19,815 pounds 
  • Stone, sand, and gravel  1.61 million pounds 
  • Zinc 671 pounds 

Now consider that there were 4,315,000 babies born in 2007 (U.S. Census Bureau). So when you start multiplying the amounts of estimated use of each of the minerals you can quickly see 6,841 mines is not really a whole lot!

Lithium, Cadmium, Cobalt, Nickel By The Numbers

Chile was the leading lithium chemical producer in the world with Argentina, China, and the United States as additional major producers.  The United States remained the leading consumer of lithium minerals and compounds and the leading producer of value-added lithium materials. Incidentally only one company produced lithium compounds in the U.S. and that is at the Silver Peak Mine in Nevada run by the Chemetall Foote Corporation.  Lithium is used not only in batteries but also in ceramics and glass, lubricating greases, pharmaceuticals and polymers, air conditioning, primary aluminum production, continuous casting, chemical processing and other uses. In terms of annual quantity of lithium the USGS estimates that in the U.S in 2005 5,000,000 pounds of lithium was used in rechargeable batteries.

In terms of annual quantity of cadmium the USGS estimates that in the U.S in 2005 1,312,000 pounds of cadmium was used in rechargeable batteries.

In terms of annual quantity of cobalt (cobalt is used primarily for the battery’s electrodes) the USGS estimates that in the U.S in 2005 23,800,000 pounds of cobalt was used in rechargeable batteries.

In terms of annual quantity of nickel the USGS estimates that in the U.S in 2005 426,000,000 pounds of nickel was used in rechargeable batteries.

How Much Demand is there for these Minerals?

In 2002 it is estimated that 350 million batteries were purchased in the U.S. So if you assume that the past 7 years have been fairly consistent then you could assume that 2.4 Billion batteries were bought and in use and will eventually need to be recycled and replaced. This means that an ever increasing demand for minerals will be placed on the mines of the earth.

Thankfully there is enough available minerals and metals to be extracted from mines that at least for the time being we do not have to be overly concerned, but, indeed there will come a point decades down the road, that this will not always be true.

Until next time, Dan Hagopian – www.batteryship.com
Copyright © BatteryEducation.com. All rights reserved.

How Do Generic Aftermarket Batteries Compare with Name Brand Batteries?

Do aftermarket batteries have the same capability and longevity as their branded counterparts? In a simple word – yes – but what aftermarket batteries bring to customers (in addition to long life performance and similar technical ratings and components) is affordability.

Big brand companies get big in terms of sales and number of units sold for four reasons – product availability and reliability, marketing and advertising on a mass scale, and the ability to fulfill their product to customers. Overtime these four components will turn any company into a Big Brand – but at a price. There is a direct association between the price of product and the company’s cost. The lower the costs the lower the price – the higher the costs the higher the price you will have to pay.

As a customer of batteries what is mission critical is that your device (whether it is a laptop, PDA, two-way radio, power tool, or flashlight) works on battery power. Your device does not care whether you have a big brand battery name on it or a generic aftermarket battery!

What is important to your device is that your voltage, capacity, chemistry, and all the internal and external components meet the specific design needs of your device. For example take Apple's EC003 (the iPod Mini). The iPod Mini requires the following technical requirements:

• The exact physical dimensions for the battery compartment
• Lithium Ion Chemistry
• 3.7 volts
• a minimum of 400 mAh
• the necessary hardware (connector, fuse, charge and discharge FETs, cell pack, sense resistor, primary and secondary protection ICs, fuel-gauge IC, thermistor, pc board, and the EEPROM or firmware for the fuel-gauge IC)

Now outside of the above technical requirements the iPod Mini does not care if the battery comes from Apple or any other third party just as long as it is “100% OEM Compatible and Guaranteed to meet or exceed OEM specifications”.

So if aftermarket replacement batteries are “100% OEM Compatible and Guaranteed to meet or exceed OEM specifications” AND if aftermarket batteries are considerably lower in price why do people opt to buy OEM or branded batteries? Because consumers have been conditioned to buy the big brands because of the clever marketing and advertising that marketers pour over and over consumers.

Now I’m sure one may come with the argument that aftermarket batteries have a higher failure rate then branded batteries – but I can tell you that having been a direct part of the aftermarket and BIG brand market for 13 years (with various companies) – every manufacture and company has defects. It is a part of manufacturing regardless of the manufacturer’s name. Acceptable defect rates float between 1-2% of all units shipped. In manufacturing there is no such thing as 0% defect rate. That is why you have a product warranty with parts (money back periods and extended warranty periods).

So now since the aftermarket or NON-OEM batteries have a low defect rate, low product cost, and the exact same specs as the OEMs the only thing that would stop you from buying aftermarket batteries is your marketing condition and the size of your wallet!

Until next time, Dan Hagopian – www.batteryship.com
Copyright © BatteryEducation.com. All rights reserved.

How Long Will My Battery Last?

Most rechargeable batteries have a charge-discharge cycle that ranges between 300-500 cycles (for lithium based chemistries – NIMH can have up to 800 charge-discharge cycles and NICD chemistries can have up to 1200). A charge-discharge cycle means that a battery once at 100% draws power down to 0%. Then after recharge it will be back at 100%. This can be done 300-500 times on the same lithium based battery. Now most battery users recharge their batteries before the battery reaches 0%, this is perfectly acceptable, but still the same principles of the charge-discharge cycle limitations are in effect.

One common mistake is to assume that a battery that has a 1 year warranty will last for 365 days and when it does not last 1 year the assumption is is that the battery must be bad. This is a fallacy and an erroneous belief – in essence incorrect!

Here is why!

As I have written in other articles a battery is a device that converts chemical energy into electrical energy. Batteries have two electrodes, an anode (the negative end) and a cathode (the positive end). Collectively the anode and the cathode are called the electrodes. In between the battery’s two electrodes runs an electrical current caused primarily from a voltage differential between the anode and cathode. The voltage runs through a chemical called an electrolyte (which can be either be in a liquid, solid, or gel state). This battery consisting of two electrodes is called a voltaic cell. Most batteries today are advance forms of the voltaic cells and have additional technology packed into the battery casing to support the overall system and its connected  device. These controls include the connector, fuse, charge and discharge FETs, the cell pack, the sense resistor (RSENSE), the primary and secondary protection ICs, the fuel-gauge IC thermistor, pc board, and the EEPROM or firmware for the fuel-gauge IC.

How Does a Battery Work and What Does It Produce?

We know that the result of a battery converting chemical energy into electrical energy allows us to turn on our laptop, PDA, MP3 or even a cell-phone. But how does the conversion process take place? As stated above the batteries we use today are variable changes of the voltaic pile. In addition to the controls I listed above today’s batteries are made up of plates of reactive chemicals (Li-ion, Li-po, NIMH, NICD) separated by an electrolyte barrier (which can be either be in a liquid, solid, or gel state), and subsequently polarized so all the electrons gather on one side. The system was designed to separate both positive and negative electrons. Then after separation an electron exchange occurs and a current of electron flow moves electrons to and from the anode and cathode. Simultaneously an electrochemical reaction takes place inside the battery to replenish the electrons. The effect is a chemical process that creates electrochemical energy.

Now the electrochemical reaction that is taking place is a chemical change that is necessary in order to create electricity. One factor that needs to be understood is that electricity is the flow of electrons. Specifically, electricity is a property of subatomic particles which couples to electromagnetic fields and causes attractive and repulsive forces between them. This repulsive force between the subatomic particles creates an electric current; the flow of electric charge transports energy from one atom to another. This electrical current is measured in amperes, where 1 ampere is the flow of 62,000,000,000,000,000,000 electrons per second!

Electricity therefore is a created energy source. All electricity in fact is a created source made or converted from coal, natural gas, oil, nuclear power, wind, heat, sun, water, biomass and or other chemicals. In batteries today electricity is created by two chemicals in a solution for example: {a Solution of Lithium hexaflourophosphate (LiPF6) – a mixture of Organic Solvents: [Ethylene Carbonate (EC) + DiEthyl Carbonate (DMC) + DiEthyl Carbonate (DEC) + Ethyl Acetate (EA)]}

To create electricity within a battery first and foremost the battery's chemistry must be charged. Charging lithium can be thought of as the introduction of ions or movement of chemistry. To move the lithium chemistry (lithium-ion, lithium polymer, lithium iron phosphate, etc) you have to have a minimum voltage applied to the lithium. Most battery cells are charged to 4.2 volts with relative safe workings at about 3.8 volts. Anything less than 3.3 volts will not be enough to charge or move the chemistry. One thing to note here is that volts are an algorithmic measurement of current. So in a sense to create current through your battery you have to introduce current into your battery’s lithium .

Introducing current into your lithium is called intercalation. Intercalation is the joining of a molecule (or molecule group) between two other molecules (or groups). When it comes to charging your battery you are in effect pushing ions in and out of solid lithium compounds. These compounds have minuscule spaces between the crystallized planes for small ions, such as lithium, to insert themselves from a force of current. In effect ionizing the lithium loads the crystal planes to the point where they are forced into a current flow. The current flow is then channeled back and forth from anode to cathode and thereby creating an electrical flow to power on your device. Again this can done 300-500 times before all the ions are pushed out of the lithium and you will no longer be able to charge your device.

One final thought and that is runtime (time between charges). After each charge-discharge cycle the runtime (time between charges) is reduced by intercalation as discussed above. For example you may notice in the first 3-4 months you are getting between 3-5 hours of runtime on your battery. Then in months 5-12 (after your purchase) you notice that you are slowly getting less and less runtime in between charges until you might be getting less than 5 minutes of runtime. This is the normal use of the chemistry inside your battery and DOES NOT mean that the battery is bad, but simply has been used by you.

Until next time – Dan Hagopian, www.BatteryShip.com
Copyright © BatteryEducation.com. All rights reserved.

How Green Are Batteries?

When you peer into the world of batteries your first thought is “wow – there sure are a lot of batteries”. While this is certainly true as self directed environmentalist I wonder just how many batteries can actually be recycled. To answer the question let’s look at batteries from the manufacturing floor on up to the end user.

The battery business just as in any business requires that materials are bought, assembled into products, and eventually sold to an end user. Batteries however have an interesting collection of materials, which are designed to collect energy, store energy, and redistribute energy on demand. These processes on the surface seem very environmentally friendly but let’s see just how friendly!

As alluded to above building a battery requires basic components including: the casing, the chemistry, the electrolyte, and the battery’s specialized hardware

The Battery Casing

The purpose of a battery casing is for enclosing and hermetically sealing an internal battery body. Battery casings are manufactured in layers. The casing layers are developed from various raw materials and can include one or two polyethylene terephthalate layers (a thermoplastic polymer resin of the polyester family), a polymer layer, and a polypropylene layer (another thermoplastic polymer). The entire casing can be recycled.

The Battery Chemistry

As noted above a battery is a device that converts chemical energy into electrical energy. To convert chemical energy into electrical energy the battery must contain the chemical base to allow conversion to occur. Types of common chemicals used in batteries on the market today are:

• Lithium Ion (Li-ion)
• Lithium Polymer (Li-po)
• Lithium-thionyl chloride (Li-SOCl2)
• Lithium-sulfur dioxide (Li-SO2)
• Lithium-manganese dioxide (Li-MnO2)
• Nickel-cadmium (NICD)
• Nickel-metal-hydride (NIMH)
• Lead-acid batteries
• Reusable Alkaline

Each of these chemistries can be recycled.

The Battery’s Electrolyte

The actual conversion of chemical energy into electrochemical energy can only be done if an electron flow passes between two electrodes, an anode (the negative end) and a cathode (the positive end). The battery’s electrical current (electron flow) runs from one electrode to another through a conductive chemical called an electrolyte solution.

A basic electrolyte solution is a chemical compound (salt, acid, or base) that when dissolved in a solvent forms a solution that becomes an ionic conductor of electricity. In the battery cell the electrolyte solution is the conducting medium in which the flow of electric current between the electrodes takes place by the migrating electrons.

At the end of the battery’s electrolyte solution’s life, the spent battery acid can be neutralized using an industrial grade baking soda compound. After neutralization the acid turns into water, treated, cleaned to meet clean water standards, and then released into the public sewer system. Another option would be to convert spent battery acid into sodium sulfate, which is used in laundry detergent, glass and textile manufacturing.

The Battery’s Specialized Hardware

A battery consists of more than the casing, electrolyte, and the chemical. It requires some very specialized hardware, especially when we speak directly about a smart battery. Your typical smart battery may have a multitude of hardware components that when working in tandem not merely create electrical power and transfer it to a particular device but additionally sends data packets of information to the device so that the device can actually gauge the battery (at least in theory). Some of the common hardware features in a smart battery include: the connector, the fuse, the charge and discharge FETs, the cell pack, the sense resistor (RSENSE), the primary and secondary protection ICs, the fuel-gauge IC, the thermistor, the pc board, and the EEPROM or firmware for the fuel-gauge IC. The materials that comprise these individual components can be broken down and recycled.

So How Green Are Batteries?

Batteries are very environmentally safe, especially batteries that are rechargeable.

Until next time – Dan Hagopian, www.BatteryShip.com
Copyright © BatteryEducation.com. All rights reserved.

Lithium Battery Chemistries

Common types of lithium based batteries are in use currently and they include but not limited to:

  1. Lithium Ion (Li-ion)
  2. Lithium Polymer (Li-po)
  3. Lithium-thionyl chloride (Li-SOCl2)
  4. Lithium-sulfur dioxide (Li-SO2)
  5. Lithium-manganese dioxide (Li-MnO2)

Lithium Ion (Li-ion)

  • The lightest of all metals
  • The greatest electrochemical potential
  • The largest energy density for weight.
  • The load characteristics are reasonably good in terms of discharge.
  • The high cell voltage of 3.6 volts allows battery pack designs with only one cell versus three.
  • Is is a low maintenance battery.
  • No memory and no scheduled cycling is required to prolong the battery's life.
  • Lithium-ion cells
  • cause little harm when disposed.
  • It is fragile and requires a protection circuit to maintain safe operation.
  • Cell temperature is monitored to prevent temperature extremes.
  • Capacity deterioration is noticeable after one year (whether the battery is in use or not).

Lithium Polymer

  • The lithium-polymer differentiates itself from the conventional battery in the type of electrolyte used (a plastic-like film that does not conduct electricity but allows ion exchange – electrically charged atoms or groups of atoms).
  • The polymer electrolyte replaces the traditional porous separator, which is soaked with electrolyte.
  • The dry polymer design offers simplifications with respect to fabrication, ruggedness, safety and thin-profile geometry.
  • Cell thickness measures as little as one millimeter (0.039 inches).
  • Can be formed and shaped in any way imagined.
  • Commercial lithium-polymer batteries are hybrid cells that contain gelled electrolyte to enhane conductivity.
  • Gelled electrolyte added to the lithium-ion-polymer replaces the porous separator. The gelled electrolyte is simply added to enhance ion conductivity.
  • Capacity is slightly less than that of the standard lithium-ion battery.
  • Lithium-ion-polymer finds its market niche in wafer-thin geometries, such as PDA batteries.
  • Improved safety – more resistant to overcharge; less chance for electrolyte leakage.

Lithium-manganese dioxide (Li-MnO2)

  • Lithium-manganese dioxide cells have a metallic lithium anode (the lightest of all the metals) and a solid manganese dioxide cathode.
  • Lithium-manganese dioxide cells are immersed in a non-corrosive, non-toxic organic electrolyte.
  • They deliver a voltage of 2.8 V and are cylindrical in shape, in 1/2 AA to D format, with spiral electrodes.

Lithium-sulfur dioxide (Li-SO2)

  • Lithium-sulphur dioxide cells have a metallic lithium anode (the lightest of all the metals) and a liquid cathode comprising a porous carbon current collector filled with a sulphur dioxide (SO2) solution.
  • They deliver a voltage of 2.8 V and are cylindrical in shape, in ½ AA to double-D format, with spiral electrodes.
  • Lithium-sulphur dioxide cells have a high energy density (250 Wh/kg) and a good capability for delivering repeated bursts of high power (up to 400 W/kg), derived from the spiral construction and is utilised in most of the applications addressed by this type of cell.

Lithium-thionyl chloride (Li-SOCl2)

  • Lithium-thionyl chloride cells have a metallic lithium anode (the lightest of all the metals) and a liquid cathode comprising a porous carbon current collector filled with thionyl chloride (SOCl2).

They deliver a voltage of 3.6 V and are cylindrical in shape, in 1/2AA to D format, with spiral electrodes for power applications and bobbin construction for prolonged discharge.

  • Lithium-thionyl chloride cells have a high energy density, partly because of their high nominal voltage of 3.6 V. Bobbin versions can reach 1220 Wh/L and 760 Wh/kg, for a capacity of 18.5 Ah at 3.6 V in D format. Because self-discharge is extremely low (less than 1% per year), this kind of cell can support long storage periods and achieve a service life of up to 20 years.

    • Until next time – Dan Hagopian, BatteryShip.com
    Copyright © BatteryEducation.com. All rights reserved.

    How Many Cells Are In A Battery

    Question from a reader: “How many cells are in the Toshiba Satellite M105-S3041 Laptop Battery? The battery is for a Toshiba Satellite M105-S3041 and its technical ratings are 10.8 volts 8800 mAh, Lithium Ion

    The question from the reader is a great question for it gets to the heart of battery manufacturing and begins to unravel the power of a battery. The answer is simply: 12 cells. But what does the answer mean and how does the number of cells relate to the overall value of a battery? Let’s find out…

    What is a Battery and How Does it Create Energy?

    A battery is a device that converts chemical energy into electrical energy. Batteries have two electrodes, an anode (the negative end) and a cathode (the positive end). Collectively the anode and the cathode are called the electrodes. What is positve and what is the negative terminal? It would be great to simply say that the anode is negative and the cathode is positive, however, that is not always the case. Somtimes the opposite is true depending on battery technology.

    In between the battery’s two electrodes runs an electrical current caused primarily from a voltage differential between the anode and cathode. The voltage runs through a chemical called an electrolyte (which can be either liquid or solid). This battery consisting of two electrodes is called a voltaic cell.

    Therefore batteries in effect create electrochemical energy. In order to convert chemical energy into electrical energy there is a chain of events that have to occur prior to the creation of electrical energy. Key to the creation of electrochemical energy in batteries is that electrical energy is injected into two chemicals in a solution. Electricity is introduced into a battery via a charger. The charger acts as a conduit of the pushing electrons that are forcing their way into the chemical lithium. This charge process involves intercalation: the joining of a molecule (or molecule group) between two other molecules (or groups). Intercalation is the process of ions being pushed by electrical current into solid lithium compounds. Lithium is one of the chemical components used to create electrical energy in batteries. Lithium compounds have minuscule spaces between the crystallized planes for small ions to insert themselves from a force of current. Ionizing lithium loads the crystal planes to the point where they are forced into a current flow. Intercalation replenishes, in effect, lithium but the net result of ionization is the ultimate depletion of the lithium reactive property. You could say if you use it you will lose it!

    But what makes lithium good for batteries is that lithium is one of the metals in the alkali group (the other metals include Sodium, Potassium, Rubidium, Cesium, and Francium). Lithium is a highly reactive metal. Lithium has only one electron in its outer shell (two electrons in its inner shell), which makes it chemically “ready” to lose that one electron in ionic bonding with other elements. Lithium is used as a battery anode material (due to its high electrochemical potential). Electrochemical potential is the sum of the chemical potential and the electrical potential. The higher the electrochemical potential the better the electrical current yields. In some lithium-based cells the electrochemical potential can be five times greater than an equivalent-sized lead-acid cell and three times greater than alkaline batteries. One other core advantage that lithium has is that it is soft and bendable which allows for tight configurations in small cell designs (PDAs. Laptops, Cameras etc…).

    What Type of Lithium Cell is Used in Laptops

    Now this brings us to battery cells and our original question from the reader. Lithium based battery cells are good but there are a variety of lithium based battery cells. For example the lithium based cell identified as 18650 is one of the most common battery cell on the market for laptops. 18650 is manufactured by many manufacturers including many private branded companies to public companies like LG, Sony, Sanyo, Samsung, Panasonic.

    18650 is a 3.6V cylindrical Li-Ion cell. 18650 has no memory effect (distinguish between digital memory effect) and longer storage life than NiMH battery cells. 18650 is light weight and has a high energy density. It is in effect perfect for building batteries for laptop and other portable power devices.

    The additional technical specifications for the 18650 battery cell include:

    • Nominal Voltage Average 3.7 V – the concept of nominal voltage is that voltage range exists depending on the number of cells in the battery.
    • Nominal Capacity – 2200 mAh (above 2200 the stability of lithium based cells is called into question)
    • • Max. Charging Current – 2.4 Amps Max.
    • • Max. Discharging Current – 4.6 Amps max.
    • • Dimensions (DxH)  18.3 mm (Max 18.4) x 64.9 mm (Max 65.1)
    • • Weight   46.5 g (1.64 oz) 
    • Internal Impedance  Internal Impedance: less or equal to 90 ohms 
    • Cycle Performance is 80% of initial capacity at 300 cycles

    Now as stated above the reader asked how many cells were in the Toshiba Satellite M105-S3041 Laptop Battery? The battery is rated at 10.8 volts and a capacity of 8800 mAh.

    As I mentioned above the nominal voltage average is 3.7V. Some manufacturers may use 3.6V and some may use 3.7V. In the case of a laptop battery with 10.8V the nominal voltage rating used is 3.6V. Thus if we divide 10.8V by 3.6V we get 3. Thus 3 cells in a series. We also know that the batteries capacity is 8800 mAh. We know the nominal capacity is 2200 mAh. Therefore if we divide 8800 mAh by 2200 mAh then we get 4 in parallel.

    Therefore we have 3 cells in series X 4 cells in parallel equals 12 cells in total.

    Until next time Dan Hagopian www.batteryship.com
    Copyright © BatteryEducation.com. All rights reserved.

    Voltage Failure Modes

    Question from a reader: "Hi Dan, What is the failure mode for Lithium Polymer batteries? I understand that Nickel Cadmium batteries fail as a short circuit usually. Therefore, a pack of NiCads will continue to operate with a shorted cell but with a voltage that is one cell lower. Do LiPo's fail…resulting in the loss of the entire pack? Thanks

    Answer: 

    First of all the reference to a "failure mode" is not necessarily a singular event. It is in effect a catch-all phrase representing potential problems. I wrote an article series on the concept of Battery Failure Mode and Effects Analysis. But this concept is not new but is manufacturing quality assurance analysis, in essence, be applied to every industry.

    The article series can be accessed at:

    Part 1
    http://www.batteryeducation.com/2008/07/battery-failure.html
    Part 2
    http://www.batteryeducation.com/2008/07/battery-failu-1.html
    Part 3
    http://www.batteryeducation.com/2008/07/battery-failu-2.html

    Specific to your question on lithium polymer batteries there could be a number of "failure mode(s)" and sub-failure modes related to the manufacturing and personal usage of a battery including Li-Po chemistry based cells. For example:

    • Batteries can have faulty cell design
    • Batteries can be manufactured under uncontrolled processes
    • Batteries can be operated in uncontrolled conditions
    • Batteries can be abused
    • Batteries can degrade and lose power

    For more information on these examples please see:
    http://www.batteryeducation.com/2006/06/what_causes_bat.html

    Heat and water for example are not good for any battery. But it is surprising to me how many people use their battery and device in both and of course that represents several failure modes. An example is when one of our customers several years ago always took his iPod mini into the sauna at his gym. Well that is not the best place for a battery or device. Eventually his battery died and so did the device. That is a bad failure mode brought about be a user. Another example is when there are metallic electrode shavings evident in the batteries electrolyte. When current is running from one electrode to another through the electrolyte the shavings cause any battery to short circuit. The short circuiting could result in the battery smoking, bubbling or stopping. That is an example of bad manufacturing and of course a failure effect. Another example of a failure mode is when you open the battery casing. If you open the casing once it is sealed hermeneutically then you run the big risk of causing a failure mode to occur.

    In any event – any failure mode will cause a battery to either operate at a lower performance than originally designed or stop working period. One interesting side note is that devices can operate with a battery that is at a lower voltage (but not higher voltage) as the device originally manufactured. The reason is because a battery's voltage is not necessarily a static measurement.

    Volts – or V – are an electrical measure of energy potential. Voltage can also be thought of as the amount of "pressure" of electrons that pass from a negative connector to a positive connector. Or V can be defined as the measure of the strength of an electrical source of power for a given current level.

    Voltage can also be defined as the Electrical Potential difference – a quantity in physics related to the amount of energy that would be required to move an object from one place to another against various types of force. In the fields of electronics the electrical potential difference is the amount of work per charge needed to move electric charge from the second point to the first, or equivalently, the amount of work that unit charge flowing from the first point to the second can perform.

    Mathematically voltage is commonly measured by V= I x R; where V=Voltage, I=Current, R=Resistance.

    Beyond the definition what challenges many is the confusion that a battery contains four unique types of voltage measurements.
    Each voltage measurement type residing in a battery effects battery life.

    • Float Voltage – is battery voltage at zero current (with battery disconnected).
    • Nominal Voltage – is battery voltage range 3.7V, 5.2V, 10.2V, 12V etc that says that a voltage range exists depending on the number of cells in the battery. For example a 12 Volt battery is made of 6 cells and has a Float voltage of about 12V.
    • Charge Voltage – The voltage of a battery while charging.
    • Discharge Voltage – The voltage of a battery while discharging. Again, this voltage is determined by the charge state and the current flowing in the battery. 

    So in effect it is possible that a device will operate on a battery at lower voltage. I hope this answers your question.

    Until next time Dan Hagopian www.batteryship.com
    Copyright © BatteryEducation.com. All rights reserved.

    Battery Manufacturing and Cell Grades – Part 2

    Battery cell grades are a classification system that manufacturers use to distinguish the benefits of capacity and runtime.

    What are battery cell grades? How do manufacturers use cell grades in the manufacturing of batteries? How do the different grades affect the quality of a battery? In part 2 of this article series we will continue where we left off and look at the battery cell grade classification system that battery manufacturers use during the process of collecting raw battery material, developing design specifications, and assembling packs for various consumer and industrial applications.

    Battery cell grades are a classification system that manufacturers use to distinguish the benefits of capacity and runtime. Before I unpack that answer we need to understand that battery grades are not a measure of quality! Battery grades do not imply that one grade is “better” than another but a reflection of capacity and internal resistance at different price points.  Before I continue with cell grades it is important to understand capacity and internal resistance.

    Battery capacity quantifies the total amount of energy stored within a battery. Battery capacity is rated in Ampere-hours (AH), which is the product of: AH= Current X Hours to Total Discharge. Battery capacity is measured in amperes, which is the volume of electrons passing through the batteries electrolyte per second. A milliAmp hour (mAh) is the most commonly used notation system for consumer electronic batteries. Note that 1000 mAh is the same as 1 Ah. (Just as 1000mm equals 1 meter). In essence more capacity equals longer runtime between battery charges.

    Internal resistance, known as impedance, determines the performance and runtime of a battery. It is a measure of opposition to a sinusoidal electric current. A high internal resistance curtails the flow of energy from the battery to a device. Internal resistance is caused primarily from the opposition of current by the electrolyte that resides between a battery’s two electrodes.

    Now battery cell grading is a process of categorizing cells into grades (Grade A, Grade B, and Grade C). Every grade is important to the manufacturer, meaning there is not one grade that is better than another. In fact every manufacturer wants to make and sell each cell grade because of the unique differences of each grade and because each cell grade has a specific market and device segment.

    As mentioned above cells are always categorized to be graded A, B and C but there is not a single manufacturing standard for categorizing cells; each manufacturing factory may have their own standard so thus cell grade categorization is not necessarily scientific.

    For example, Li-ion cell 053450, some companies may categorize the cell as follows

    Grade A— capacity above 1000mAh, internal resistance below 60mΩ
    Grade B—capacity 900 to 1000mAh, internal resistance 60mΩ to 80mΩ
    Grade C—capacity below 900mAh, internal resistance above 80mΩ

    But for some companies with better production lines and capability, they may have higher capacity cells so they may categorize cell 053450 as follows:

    Grade A— capacity above 1100mAh, internal resistance below 60mΩ
    Grade B—capacity 1000 to 1100mAh, internal resistance 60mΩ to 80mΩ
    Grade C—capacity below 1000mAh, internal resistance above 80mΩ

    One generally accepted conclusion can be drawn from these two examples and that is grade A cells have the longest runtime and cycle life, grade B has the second longest runtime and cycle life and grade C has the third longest runtime and cycle life.

    Until next time Dan Hagopian www.batteryship.com
    Copyright © BatteryEducation.com. All rights reserved.

    Battery Manufacturing and Battery Cell Grades – Part 1

    What is involved when a battery is manufactured? What materials are needed to manufacture a battery? What are battery cell grades? What do battery grades mean? How do the different grades affect the quality of a battery? How can you know what battery grade you have? And is any one grade more important then another?

    What is involved when a battery is manufactured? What materials are needed to manufacture a battery? What are battery cell grades? What do battery grades mean? How do the different grades affect the quality of a battery? How can you know what battery grade you have? And is any one grade more important then another?

    To understand battery cell grades we have to understand how batteries are manufactured. Battery manufacturing involves the collection of raw material, the development and setting of design specifications, and the assembly of an individual battery pack. On a very high level that is ultimately what is involved when a battery is made.  Furtherore battery manufacturers utilize manufacturing principles, much like manufacturers of other products, to get the batteries made efficiently and effectively. 

    When it comes to the collection of raw materials manufacturers have to collect very specific material to be used in the assembly of battery packs. This material includes the following:

    The casing – for enclosing and hermetically sealing a battery body – is manufactured in one, two, or three layers that include for example polyethylene terephthalate layers, a polymer layer, and a polypropylene layer.

    The chemistry which is often times lithium based for its high electrochemical potential. An example could be a {Solution of Lithium hexaflourophosphate (LiPF6) – a mixture of Organic Solvents: [Ethylene Carbonate (EC) + DiEthyl Carbonate (DMC) + DiEthyl Carbonate (DEC) + Ethyl Acetate (EA)]}.

    The electrolyte – The actual conversion of chemical energy into electrochemical energy can only be done if an electron flow passes between two electrodes, an anode (the negative end) and a cathode (the positive end). The battery’s electrical current (electron flow) runs from one electrode to another through a conductive chemical called an electrolyte solution.

    The battery’s specialized hardware that includes: the connector, the fuse, the charge and discharge FETs, the cell pack, the sense resistor (RSENSE), the primary and secondary protection ICs, the fuel-gauge IC, the thermistor, the pc board, the EEPROM or firmware for the fuel-gauge IC..

    Now part of the manufacturing process is the categorization of battery cells. Categorizing battery cells are done in grades (Grade A, Grade B, and Grade C). In part 2 of this article series I will explain what the different grades mean and how manufacturers use the different grades and what the grades mean to you and your battery.

    Until next time Dan Hagopian www.batteryship.com
    Copyright © BatteryEducation.com. All rights reserved.

    Rechargeable Batteries Can Only Be Charged 300-500 Times – Part 2

    In the last two articles we addressed how and why rechargeable batteries have limited charge cycles. We reviewed in detail the effect of a charge-discharge cycle – a chemical change in a battery system that results in degradation and power loss. But there is one aspect in my last article that deserves special attention. This one factor is the basis of battery degradation. It is the reason why batteries can never just keep going and going and going. The fact is, is that all batteries degrade and lose power because there is a reduction in the battery’s active material.

    We know that a battery is a device that converts chemical energy into electrical energy. In order to convert chemical energy into electrical energy there is a chain of events that have to occur prior to the creation of electrical energy. The chain of events have been discussed in depth in previous articles which you can access on my blog but what is key to the creation of electricity is that in batteries electrical energy is produced from two chemicals in a solution. After discharging you recharge the battery via a charger. The charge process involves intercalation: the joining of a molecule (or molecule group) between two other molecules (or groups). Intercalation is the process of ions being pushed by electrical current into solid lithium compounds. Lithium is one of the chemical components used to create electrical energy in batteries. Lithium compounds have minuscule spaces between the crystallized planes for small ions to insert themselves from a force of current. Ionizing lithium loads the crystal planes to the point where they are forced into a current flow. Intercalation replenishes, in effect, lithium but the net result of ionization is the ultimate depletion of the lithium reactive property. You could say if you use it you will lose it!

    Why then is lithium used as the chemical to create electricity in batteries? There are a number of good reasons – let’s look at a few!

    General Characteristics of Lithium

    • Name: lithium
    • Symbol: Li
    • Atomic number: 3
    • Atomic weight: [6.941 (2)] g m r
    • CAS Registry ID: 7439-93-2
    • Group number: 1
    • Group name: Alkali metal
    • Period number: 2
    • Block: s-block
    • Standard state: solid at 298 K
    • Color: silvery white/grey
    • Classification: Metallic

    Lithium is one of the metals in the alkali group (the other metals include Sodium, Potassium, Rubidium, Cesium, and Francium). Lithium is a highly reactive metal. Lithium has only one electron in its outer shell (two electrons in its inner shell), which makes it chemically “ready” to lose that one electron in ionic bonding with other elements. Lithium is used as a battery anode material (due to its high electrochemical potential). Electrochemical potential is the sum of the chemical potential and the electrical potential. The higher the electrochemical potential the better the electrical current yields. In some lithium-based cells the electrochemical potential can be five times greater than an equivalent-sized lead-acid cell and three times greater than alkaline batteries. One other core advantage that lithium has is that it is soft and bendable which allows for tight configurations in small cell designs (PDAs. Laptops, Cameras etc…).

    Lithium, even with all of its good chemical properties will eventually, however, react to the point where the electrochemical potential will yield a charge that is simply not enough to create current to pass to power a device.

    Until next time Dan Hagopian www.batteryship.com
    Copyright © BatteryEducation.com. All rights reserved.