BatteryEducation – Page 34 – Battery Education

100 Million iPod Batteries

100,000,000 iPod owners and counting! A remarkable tribute to Apple’s iPod music player – no question! I wonder how many of these iPod owners know how their iPod battery works. Understandably most people don’t really care as long as it does. However I am interested and I’m sure there are others out there as well who want to know how their iPod battery actually delivers power to their iPod.

Most people would never realize how complex an iPod battery is nor would they realize how many components can be found within their iPod battery. For starters your iPod battery is made up of highly specialized battery components including:

iPod battery connector
iPod battery fuse
iPod battery charge and discharge FETs
iPod battery cell pack
iPod battery sense resistor
iPod battery primary and secondary protection ICs
iPod battery fuel-gauge IC
iPod battery thermistor
iPod battery pc board

These components together allow your iPod battery to function so that you can listen to music while doing the various activities of your day. Before we can delve deep into each of these ipod battery components I want to make sure that we understand that these components together work in an effort to produce electrical current to supply to the iPod.

iPods require electrical power in order to function. iPods’ draw electrical current on demand from your iPod battery. However your iPod battery is not a storage house of electrical energy but instead your iPod battery is your iPod’s internal electrical “factory” that creates electrical energy through a process known as an electrochemical energy conversion and subsequently your iPod battery delivers electrical current to your iPod. The electrochemical energy conversion is a process of replenishing of electrons and it is this electron replenishment that causes the chemical conversion to take place and create the electrical energy byproduct. To understand electrochemical conversion let’s see how electricity is created in the first place.

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. Electrical current is measured in amperes, where 1 ampere is the flow of 62,000,000,000,000,000,000 electrons per second!

Inside your iPod battery engineers have designed a constant state of disequilibrium, which cause a continuous flow of electrons. When electrons move between the atoms (atoms are made up of particles called protons, neutrons, and electrons) a current or flow of electricity is created. But how is this current of electricity created to begin with? This comes back to our electrochemical conversion. In order to create electrical energy (or a constant state of disequilibrium, which cause a continuous flow of electrons) there must be an electrochemical system which includes the electrodes and the electrolyte housed within your battery. Electrons flow from one electrode to another and the electron flow is conducted by an electrolyte. In ipod batteries for example an electrochemical system can be comprised of the electrodes consisting of Carbon/Graphite for the negative electrode and Lithium cobaltite for the positive electrode. Between these electrodes is an electrolye which can be a highly conductive solution consisting of lithium hexafluorophosphate. The electrolyte solution is a chemical compound that when dissolved in a solvent (i.e. water) forms a solution that becomes an ionic conductor of electricity. Hence the electrochemical conversion!

Once the electrochemical conversion begins then the balance of the ipod battery’s specialized hardware components I mentioned above can be put to work transferring and monitoring the iPod battery and the iPod – all for the sole purpose of delivering power to your iPod.

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

What is Inside My iPod Battery?

The iPod is the fastest selling music player, selling over 100,000,000 iPods in the last 5 years! In fact just in the last 3 months of 2006 Apple sold 21 million iPod players. So it is no real surprise that 48% Apple’s $7.1 billion in revenue is comprised of iPod sales. Wow quite an accomplishment!

There is downside to this and that is the 100 million people who bought an iPod will at one point or another need to have their iPod battery replaced. The good news about replacing your iPod battery is that iPod battery replacements can be done relatively easily and cost right around $10. iPod battery replacements kits come with tools and you can find your iPod’s battery online or at retailer’s like www.Batteryship.com.

However since so many people have purchased an iPod and since the demand for iPod batteries is quite high it is my curiosity to take a quick peek inside the iPod battery to find out what inside makes it work!

All iPod Batteries will ultimately fail, stop working, and cease to operate, and or otherwise end their useful life. It is the nature of the ipod battery’s design. iPod battery’s are designed to power iPods for a specific amount of time and are also designed with a certain number of battery charge cycles before the battery will not hold enough charge to power your iPod.

But let’s take a step back for just a moment and look at how iPod batteries work and why? First of all iPod batteries are in effect a device that converts chemical energy into electrical energy. iPod batteries have two electrodes, an anode and a cathode and running in between the two nodes 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).

The most common cause of battery failure is not really a battery failure but normal internal battery wear or use. This is technically classified as declining capacity, increasing internal resistance, elevated self-discharge, and or premature voltage cut-off on discharge. Of these normal battery wear and tear factors the most common is declining capaicty caused by the creation and transfer of chemical energy into electrical energy.

The chemical used to create electrical energy is lithium polymer. Lithium polymer is used as a battery anode material in dry cells and storage batteries. In fact the energy of some lithium-based cells can be five times greater than an equivalent-sized lead-acid cell and three times greater than alkaline batteries. Lithium cells often have a starting voltage of 3.0 V. This means that batteries can be lighter in weight, have lower per-use costs, and have higher and more stable voltage profiles. Some specific benefits of the lithium polymer chemical includes:

Lithium polymer chemistry uses a plastic-like electrolyte film that does not conduct electricity but allows ion exchange – electrically charged atoms or groups of atoms.
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.
Lithium polymer offers a safer design – it is more resistant to overcharge; and is less prone to electrolyte leakage.

In addition to the iPod battery’s cell chemistry there are other specific hardware components that makeup the iPod battery and that together, working in concert with the battery cell that allow the iPod battery to push electrical current to your iPod. These specialized hardware components include:

the iPod battery connector
the iPod battery fuse
the iPod battery charge and discharge FETs
the iPod battery cell pack
the iPod battery sense resistor
the iPod battery primary and secondary protection ICs
the iPod battery fuel-gauge IC
the iPod battery thermistor
the iPod battery pc board

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

Common Causes of Battery Failure – Part 2

All batteries will ultimately fail, stop working, and cease to operate, and or otherwise end their useful life. It is the reality of a consumable product. But sometimes batteries can warp, bubble, and even explode! Batteries can also fail due to incompatible designs or improperly selected hardware, and batteries can fail due to customer misuse or abuse.

According to the U.S. Consumer Product Safety Commission each year deaths, injuries and property damage from consumer product incidents cost U.S. taxpayers more than $700 billion annually. This cost includes over 15,000 different types of products that pose a risk of fire, electrical, chemical, or mechanical hazard or products that can injure children (cribs, toys, etc.). Batteries by their nature are 1 out of the 15,000 products the CPSC monitors because of the increased implementation of battery chemistries that pack higher energy in smaller packages. Batteries with lithium ion and lithium metal polymer chemistry are thinner, smaller, and lighter weight and contain more energy than traditional rechargeable batteries. These battery chemistries are excellent choices for small electronic devices that require higher capacities and specialized hardware to safeguard the battery from doing anything other than performing as expected within the device.

It is true that sometimes batteries can warp, bubble, and even explode. It is also true that batteries can fail. According to the U.S. Consumer Product Safety Commission there have been 339 battery-related overheating incidents tracked. 339 overheating cases sounds like a lot but when compared to the well over 100,000,000 battery related devices that have been bought by consumer since 2003 it represents a very small percentage (.000003) of all battery related devices on the market.

The reason why overheating occurs in batteries to the point of warping, bubbling, or exploding is due to one of the following reasons:

1. Improperly Selected Hardware – from the connector, the fuse, the charge and discharge FETs, the cell pack, the sense resistor, the primary and secondary protection ICs, the fuel-gauge IC, the thermistor, or the pc board

2. Uncontrolled Manufacturing Processes – including badly run production facilities which lead to cell short circuits, leaks, unreliable connections, sealing quality, mechanical weakness, and contamination.

Batteries can also fail due to customer misuse or abuse. Battery abuse can happen in a variety of ways however all types of battery abuse fall under one of the following categories including altitude simulation, thermal cycling, shock, external short circuit, impact, overcharge, forced discharge.

Finally batteries can fail due to consumer misuse. Misuse is different then abuse because battery abuse is intentional consumer disruption of the battery and battery misuse is unintentional consumer misuse of a battery. For example one common misuse of a battery is trying to use a camera battery rated and designed for a specific camera model, but used for an entirely different camera. It may sound funny but it has happened. Why because consumer’s think that just because the physical footprint, the voltage and the capacities are the same that the battery will work in multiple devices. This is a fallacy that happens frequently. To avoid this type of misuse, only use a battery that is specifically designed for the device model you have and do not battery swap.

Until next time, Dan Hagopian – www.batteryship.com

Common Causes of Battery Failure – Part 1

All batteries will ultimately fail, stop working, and cease to operate, and or otherwise end their useful life. It is the reality of a consumable product. The cost to operate a replacement battery in your device, however, is relatively cheap so it is not a catastrophe when batteries stop working (although certainly an inconvenience). Yet when batteries do fail have you ever wondered why? In my next series I will look more closely at the common causes of battery failure including:

Batteries degrade and lose the ability to power a device
Batteries can warp or bubble
Batteries can explode
Batteries can have incompatible designs
Batteries can have improperly selected hardware
Batteries can be misused or abused

Battery degradation and power loss is the normal result of internal battery use. Technically battery degradation and power loss includes declining capacity, increasing internal resistance, elevated self-discharge, and premature voltage cut-off on discharge. I have written about each of these points in depth in another article at our Battery Education blog so please see that blog for more info, but what is important to get across is the fact that battery degradation and power loss is real! Much like gravity it exists regardless if we believe that it does not!

Furthermore battery degradation and power loss begins when one of the following occurs: when the battery is charged, when the battery is connected to a device (the device does not have to be turned on), when a battery is opened, or when a battery is chemically activated in any way. Any assumption you may have where a battery could still be considered new even after it was charged, connected to a device, been opened or chemically activated in any way is faulty. Why because inside the battery itself, a chemical reaction is produced the moment any of the aforementioned factors occur to begin electron flow. The chemical reaction is purposely designed to create electron flow (i.e. electricity). The electron flow is measured (or moves at speeds) in amperes, where 1 ampere is the flow of 62,000,000,000,000,000,000 electrons per second! Therefore once the chemical is activated and the flow of electrons takes place, even for a second, then the loss of power and battery degradation begins and there is no stopping it. Once battery degradation begins a battery is considered used and its natural life will deplete in a matter of time.

In part 2 of the series I will look at some of the other reasons why batteries fail including batteries that warp, bubble, explode, and batteries that have incompatible designs or improperly selected hardware.

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

Lithium ion Batteries Explode?

"A cellphone exploded in his living room last year, causing up to $100,000 in damages. Ortega and his family had to live in a trailer for a few months while their house in California was fixed" as reported in the Chicago Tribune back in 2006. Without question the impact that the fire had on this family is devastating but what is alarming about that fire is that through the fire and insurance investigation the cause was found to be due to a cell phone's lithium-ion battery failure and subsequent spontaneous combustion. What? How is that possible?

If you have a PDA, MP3, MP4, Laptop, Cell Phone, Smartphone, DVD player, or other electronic device then more likely then not the battery within your device is a high capacity smart battery pack (the chemical base being lithium ion). What is a high capacity smart battery pack? A high capacity smart battery pack is a complex battery system designed to power high tech consumer electronic products.

What differentiates smart batteries from standard batteries is the specialized hardware that provides calculated on demand current as well as predicted information.

This specialized hardware 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

Each of these components working in concert allows electrical current to be created, controlled, and transferred to your individual electronic device on demand. Your battery in effect was purposely designed to be an energy dense power pack, which used within its properly designed purpose you can feel comfortable that your battery will not explode.

How can I say that you will “feel comfortable” because statistically your battery will not explode or even become defective! The report about the fire at the Ortega’s family house is one of 339 battery-related overheating incidents tracked by the Consumer Product Safety Commission since 2003. 339 overheating cases sounds like a lot but when compared to the well over 100,000,000 battery related devices that have been bought by consumer since 2003 it represents a very small percentage (.000003) of all battery related devices on the market.

However when smart batteries do explode, bubble, or warp the cause is due to an internal cell short that may cause the battery to overheat and explode, posing a potential hazard to consumers.

To isolate the ultimate cause of the short circuit a study of every aspect of the smart battery development and customer use must be considered including:

the specialized each of the hardware components
the cell design
the manufacturing processes
battery operation in extreme conditions
intentional battery abuse
unintentional abuse through the use of the battery in any device, product, and or in any conceivable manner other than what the battery was specifically designed to be used for and in

So yes it is possible to have high capacity smart battery pack explode and cause unexpected damage but as we have seen it is very unlikely considering the sheer quantity of lithium ion based batteries on the market.

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

Dissecting A Smart Battery – Part 3

In my first two articles of the series Dissecting A Smart Battery I discussed the specialized hardware contained in the smart battery including the connector, the fuse, the charge and discharge FETs, the cell pack, and the the sense resistor (RSENSE). In my final article of the series “Dissecting A Smart Battery” I would like discuss some of the other important hardware features contained in a smart battery.

As we have done in the first two parts of Dissecting A Smart Battery let’s recap the specialized hardware we have talked about. Included in the smart battery are the following specialized hardware:

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.

The Primary and Secondary Protection IC

Integrated Power Management Circuits protects against over-voltage, and under-voltage conditions and they maximize battery life between charges, minimize charging times, and improve overall battery life. Batteries for PDAs, MP3s, Digital Cameras, and Laptops for example have designed within them integrated power management circuits that insure that the deliverance of reliable power is properly managed. Without these power management integrated circuits even fine tuned handhelds will exhibit problems such as over-voltage, and under-voltage conditions. Incidentally, overcharging is potentially a very dangerous problem. Overcharging is the state of charging a battery beyond its electrical capacity, which can lead to a battery explosion, leakage, or irreversible damage to the battery. It may also cause damage to the charger or device in which the overcharged battery is later used.

An integrated circuit in general is a miniaturized electronic circuit. An electrical circuit is a network that has a closed loop, giving a return path for current. The goals of integrated circuits are multifaceted, for example when designing for signal processing integrated circuits apply a predefined operation on potential differences (measured in volts) or currents (measured in amperes). For batteries the use of integrated circuits with the goal of power management is integrated battery management which include voltage regulation and charging functions. Power management integrated circuits offer other key benefits as well including maximizing battery life between charges, minimize charging times, and improve battery life. The other critical aspect of power management integrated circuits is their functioning design to detect and monitor voltage levels in batteries. When certain parameter thresholds are exceeded or dangerous conditions exist, these “supervisory circuits” react through a programmable logic design to protect the monitored system and correct problems as programmed. Supervisory circuits are known by a variety of names, including battery monitors, power supply monitors, supply supervisory circuits and reset circuits. They perform critical functions including power-on-reset (POR) protection to ensure that processors always start at the same address during power-up. Without POR, even well-functioning systems can exhibit problems during power-up, power-down, over-voltage, and under-voltage conditions.

The Fuel-gauge IC

We may all be familiar with the battery charge indicator on our device. The little blinking light or bar meter indicator that let’s us know when we need to recharge our battery. But did you know that the calculation of the remaining battery capacity (power) is performed within the battery and that calculation is transmitted to the device from within the battery to the device through the connector. The calculation of remaining battery capacity is performed by the fuel-gauge integrated circuit. The fuel-gauge stores cell characteristics and application parameters used in the calculations within the on-chip EEPROM (which we will discuss shortly). The available capacity registers report a conservative estimate of the amount of charge that can be removed given the current temperature, discharge rate, stored charge and application parameters. Capacity estimation is then reported in mAh remaining and percentage of full charge.

The Thermistor

A thermistor is a temperature-sensing element. The thermistor is used to determine starting temperature and prevent charging if the battery temperature is too low or too high. The battery charger also uses the thermistor as an external thermal sense that provides input to temperature sense for the fuel gauge.

The PC Board

All the components that we have discussed throughout the series on Dissecting A Smart Battery (the connector the fuse the charge and discharge FETs, the cell pack, the sense resistor, the primary and secondary protection ICs, the fuel-gauge IC, the thermistor) is at one point within the battery connected to a PC Board. The PC Board or printed circuit board is used to mechanically support and electrically connectthe aforementioned specialized hardware using conductive pathways, or traces, etched from copper sheets laminated onto a non-conductive substrate.

The EEPROM

Lastly I want to discuss the EEPROM, which stands for the electrically erasable programmable read only memory of the smart battery. It is a reference in effect to the user programmable integrated circuits memory devices which retain stored information in the absence of electrical power and in which the information may be altered electrically.

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

Dissecting A Smart Battery – Part 2

In part 1 of Dissecting A Smart Battery I mentioned that smart batteries have contained within them specialized hardware that when working in concert provides the power necessary to run a device such as a PDA, digital camera, or ipod player. Continuing the dissection of a smart battery this article of the series will look at the smart battery’s fuse, charge and discharge FETs , the cell pack, and the sense resistor (RSENSE) to discover what role they each play within the smart battery.

Before we begin let’s just recap some of the specialized hardware within the smart battery:

1. the connector
2. the fuse
3. the charge and discharge FETs
4. the cell pack
5. the sense resistor (RSENSE)
6. the primary and secondary protection ICs
7. the fuel-gauge IC
8. the thermistor
9. the pc board
10. the EEPROM or firmware for the fuel-gauge IC.
11. and the SMBus

The Smart Battery Fuse

When we discuss fuses in relation to electronics we are speaking directly of a fusible link that is responsible for protecting the device from over current. Fusible links have a metal wire that melts when heated to a predetermined electric current rating. When melted the electrical circuit is opened and thereby protecting the circuit from an over-current condition. The obvious concern here is the selection of the fuse – an improperly selected fuse will not protect from over-current conditions and the result will be a fire or damage due to a short circuits.

In a smart battery a typical fuse has three-terminal components that limit current flow based on the temperature, current, and or power across the heating wire. Besides temperature ratings other important factors when selecting the proper fuse to work with each smart battery is hold current, trip current, maximum battery voltage, and fuse size.

The Smart Battery’s FET (field effect transistor)

Smart batteries must have a series FET (field effect transistor) switch to open and protect the battery’s cells. A FET is a transistor that uses an electric field to control the conductivity of a particular 'channel' in a semiconductor material. FETs at times are used as voltage-controlled resistors. As such field effect transistors are chosen based upon their designed ability to dissipate on demand power.

The Smart Battery’s Cell Pack

The battery cell can be thought of as the holding area of the battery’s chemical. The battery cell pack is critical to the overall capability of the smart battery. Cell packs have to be designed and integrated based upon the vitals of the battery including chemistry type (Li-ion, Li-po, NICD, NIMH, etc.) cycle life, storage-capacity loss, shelf life, impedance, capacity at different rates of discharge and temperature, and mechanical and environmental requirements. It is critical to say the least.

The Smart Battery’s Sense Resistor

The final specialized hardware I want to review in this article is the sense resistor (RSENSE). In electronics, sense, is generally referred to the task of producing the correct voltage. Current not temperered will cause damage so sense resistors need to be integrated in order to control power and temperature.

In my next article on the dissection of a smart battery I will cover secondary protection ICs, the fuel-gauge IC, the thermistor, the pc board, and the EEPROM.

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

Dissecting A Smart Battery – Part 1

Smart Batteries – they are used in PDAs, MP3s, MP4s, Laptops, Cell Phones, Smartphones, DVD players, and other electronic devices. When we buy new batteries we want them to work. We really don’t care how they work just as long as the do. But since PDA Batteries are a unique interest for me and since pda batteries are smart batteries I’m going to dig a little deeper to discover what lies within PDA batteries. So follow along as I dissect a pda battery to learn what it is made of!

Contained within a smart battery is specialized hardware. Hardware that has a specific purpose: to deliver calculated and on demand current as well as predicted information.

This specialized hardware includes:

But what are each of these components and what do they do? Let’s find out?

The connector is a device that joins electric circuits together. Most battery packs require more than one connector. The main battery connector is both the mechanical and electrical part that interfaces the battery to the PDA or other electronic device. If you have ever installed a battery in your PDA then you probably have plugged your battery in by plugging/snapping in the main battery connector to the device’s PC board. Features that have to be considered when selecting a connector of a particular battery is operating temperature (range/limits) since high capacity batteries discharge excessive heat – having a connector that can withstand such temperature extremes will prevent a short circuit. Connectors also have to proper pin assignments so that current and performance capacity can be met and short-circuit thresholds are predetermined. Pin orientation within the connector has to be designed in order to fit the device. If it doesn’t well you won’t be able to connect the battery to the PDA or other electronic device. Finally the connectors has to be handle time-varying current therefore the ratio of the phasor voltage across the element to the phasor current through the element (otherwise known as impedance) has to be preset or else expect connector to not function in the way it was supposed to!

In the next article of this series I will cover the smart battery’s fuse, charge and discharge FETs , the cell pack, and the sense resistor (RSENSE). The article after the next will cover the primary and secondary protection ICs, the fuel-gauge IC, the thermistor, the pc board, the EEPROM, and the SMBus.

What is Inside A Smart Battery?

If you have a PDA, MP3, MP4, Laptop, Cell Phone, Smartphone, DVD players, or other electronic device then more likely then not the battery within your device is a high capacity smart battery pack. What is a high capacity smart battery pack? A high capacity smart battery pack is a complex battery system designed to power high tech electronic devices.

What differentiates smart batteries from standard batteries is the specialized hardware that provides calculated on demand current as well as predicted information.

This specialized hardware includes:

In addition to the above advanced chip components, I mentioned that information flows from these components to another advanced component of the smart battery and that is the smart battery’s System Management Bus (SMBus) control – a two-wire interface through which simple power-related chips can communicate with rest of the system. Typically a SMBus uses I2C as its backbone so that multiple chips can be connected to the bus. The SMBus allows a device to transfer manufacturer information, transfers model or part number to and from the device and battery, save its state for a suspend event, report different types of errors, accept control parameters and return its status.

All in all the smart battery is a highly specialized battery that functions within its intended design. Used outside its design the smart battery really won’t work too well!

Batteries – One Size Does Not Fit All

I have a Palm Zire 72 and a Palm m505 PDA. If I buy a Palm Zire 72 Battery that is 3.7 volts can I plug it into a Palm m505 and have that battery power both devices as needed?

In a nut shell the question above seeks to ascertain if all 3.7 volt batteries are the same?

The quick answer is no – all 3.7 volt batteries are “not” the same – and a battery specifically designed for a Palm Zire 72 will not be compatible with a Palm m505 PDA.

Let me explain.

It is true that all batteries share similar components and share common electrical measurements. But just because all batteries have some common components and measurements does not mean at all that you can interchange batteries with various devices even if the technical ratings are the same. Note that a component is something tangible and a measurement is intangible – a result of an action contained within the battery system.

Quick Review: What is a Battery and how does it work?

A battery in its most basic definition 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.

Electrical measurements that can be gleaned from battery operations inclued the measurements of:

Volts – or V – is the electrical measure of battery’s energy potential. For example you can think of energy potential as the pressure being exerted by all the electrons of a PDA Battery’s negative terminal as they try to move to the positive terminal.

Amps – or A – which is a measure of the volume of electrons passing through a wire in a one second. One Amp equals 6.25 x 1018 electrons per second.

Watts: Volts x Amps = Watts. Watts are important because a watt represents the electrical energy spent by a battery (power generator) and used by an electrical device. Watts in effect is the measure of the amount of work done by certain amperage (amount) of electric current at a certain pressure or voltage.

Now beyond that basic review of the common components and measurements of batteries begins the radical differences between batteries. If you have a PDA, MP3, MP4, Laptop, Cell Phone, Smartphone, DVD players, or other electronic devices then more likely then not the battery within your device is a high capacity smart battery pack.

What is a high capacity smart battery pack? A high capacity smart battery pack is a complex battery system designed to power high tech electronic devices.

To construct a smart battery the battery manufacturer must carefully plan the internal battery design environment by considering the:

• design parameters
• current requirements
• capacity and runtime requirements
• temperature requirements
• safety requirements
• ambient operational/non-operational temperatures

As a design for a smart battery pack is considered manufacturers must evaluate the differences in components in relation to their design environment. Proper component evaluation and specification selection based on the intended application will determine the ultimate performance of the entire battery.

To give you an example of why smart batteries are carefully designed consider a PDA that when turned on explodes (don’t think it can’t happen) thankfully it occurs very rarely. To be a more reassuring the US Consumer Product Safety Commission has noted that 339 battery-related overheating incidents have occurred since 2003. Since conservative estimates puts the sale and use of devices containing smart batteries in excess of 100 million battery related devices during the same period makes the 339 incidents reported by the Saftey Commission at .000003% (a very small percent) of all battery related devices on the market. What is preventing more battery related fires -reliable and safe design under worst-case conditions is especially critical when designing with lithium based batteries. Specifically over-voltage and under-voltage of the cells and over-current of the battery pack.

Now with all this said I can tell you again, almost emphatically, that not all batteries are the same. From battery to battery the internal design will be different depending on the device the battery was specifically built to work within.