WHAT IS IMEI ?

               The International Mobile Equipment Identity number uniquely identifies an

individual mobile station. The IMEI is unique to every ME (Mobile Equipment)

and thereby provides a means for controlling access to GSM networks based

on ME types or individual units.

             The IMEI format is being originated by the Mobile Telecommunication

Standardisation Authorities. Nokia cannot bear a responsibility for eventual                   additional cost arising from e.g. updating the company

housekeeping system etc.

The “IMEI” consists of a number of fields totalling 15 digits. All digits have the

range of 0 to 9 coded as binary coded decimal. Values outside this range are

not permitted.

The IMEI structure valid since 01.04.2004 is as follows

NNXXXXXX                           ZZZZZZ                      A

TAC: Type Allocation Code         SNR: Serial Number    CD: Check Digit

TAC                Type Allocation Code, formerly known as Type Approval Code

NN                  Reporting Body Identifier, e.g. BABT

XXXXXX        Type Identifier defined by Reporting Body

ZZZZZZ          Allocated by Reporting Body but assigned to individual mobile

Stations by the manufacturer

A                     Phase 1 = 0

Phase 2 & 2+ = Check digit, defined as a function of all other

IMEI digits.

IMEI structure until 31.12.2002

The IMEI structure valid until 31.12.2002 is as follows

NNXXXX             YY                 XXXXXX                A

TAC                    FAC               SNR                      CD

TAC: Type Approval Code 

 FAC: Final Assembly Code

SNR: Serial Number  SNR: Serial Number

CD: Check Digit

The meaning of the acronyms for the IMEI format valid until 31.12.2002 is:

TAC Type Allocation Code, formerly known as Type Approval Code

NN                    Reporting Body Identifier

XXXX                ME Type Identifier defined by Reporting Body

FAC                   Final Assembly Code

YY                     Under control of the Reporting Body. May be used to indicate

the manufacturing site. More than one FAC per site should be

used to permit production of greater than 1000000 ME.

A Phase 1 = 0

Phase 2 (0r later) = Check digit, defined as a function of all other IMEI digits.

IMEI structure 01.01.2003 to 01.04.2004

Structure has changed to combine the TAC and FAC into a single eight-digit

TAC code.

 To allow e.g. the operators to modify theirs systems to use the eight digit

TAC rather than a six digit one and the manufacturers to make any

necessary changes to their production processes, a transition period has

been determined to be from 31.12.2002 to 01.04.2004.

To achieve this transition, all eight-digit TAC codes allocated between

31.12.2002 and 31.03.2004 will have unique combinations of the first six

digits (NNXXXX) with the seventh and eight digits (YY) being fixed to 00.

The IMEI structure valid from until 01.01.2003 to 01.04.2004

NNXXXX                  00                  ZZZZZZ              A

TAC                         FAC                SNR                   CD

TAC: Type Approval Code

FAC: Final Assembly Code

SNR: Serial Number

CD: Check Digit

 

ESD (ELECTRO STATIC DISCHARGE)

Electronics

MOBILE PHONE BATTERY

Battery is the power source of Mobile phone.which produces electric energy by means of chemical reaction.Terminal voltage of a mobile phone battery is 3.7v. Mobile phone batteries are coming under the category of  secondary cells,which means they are rechargeable.

 According to the chemical combination,there are several types batteries used in mobile phone.they are..

1. NiCd   : Nickel Cadmium batteries
2. NiMH : Nickel Metal Hydroxide batteries
3. Li-ione : Lithium Ione batteries
4. Li-Polymer : Lithium Polymer batteries

 How ever , in recent mobile phones uses Li-Ione or Li-polymer batteries.

Memory effect in batteries

  As we recharge the battery frequently with out allowing to discharge  the stored charge fully,the unused portion of the battery will be permanently become damaged and backup capacity of the battery will be reduced this is known as Memory effect of battery.Li-ione and Li-polymer batteries has very less memory effect.

Terminals of Mobile phone Battery

Basically a mobile phone battery has three terminals.in some case there will be 4 terminals also..they are 

1. Battery positive (+ve)
2. Battery Negative (-ve)
3. BSI (Battery Size Indicators)
4. BTEMP (Battery temperature)

BSI : this terminal gives current status the amount charge in the battery.also it helps the mobile device to detect whether it is a specified battery  for it,it gives protection damages due to  accidental removal of the battery .since all these factors,there may be complaints in mobile device due to faulty or non specified batteries

COMPLAINTS DUE TO BSI TERMINALS

• Not switching on
• Restarting issue
• SIM card not detecting issue
• Automatic switching off issue.
• Charging related issue(error messages like "battery disconnected"
• Test mode/local mode issue

BTEMP : this terminals gives  the temperature of the battery while the battery being recharged.It is achieved by means of a NTC type thermister(negative temperature coefficient type) .some time this thermister will be in mother board,in such case battery will not have the btemp terminal.

COMPLAINTS DUE TO BTEMP TERMINAL

• charging issue with error message "charging paused,battery temperature too high"
• charging issue with error message "charging paused,battery temperature too low"

NFC Terminal: In some batteries ,the fourth terminals may be dedicated for the NFC (Near Field Communication)antenna eg: SAMSUNG Galaxy S3

SPECIFICATIONS OF MOBILE PHONE BATTERIES

• Battery Type
• current delivering capacity (in mAH : milli ampere per hour)

PRECAUTIONS FOR BATTERY USAGE

DANGER !!

 Disassemble and Reconstruction “Do not disassemble or reconstruct battery” The battery pack has safety function and protection circuit to avoid the danger. If they have serous damage, it will cause .the generating heat, smoke, rupture or flame.

2. Short-circuit “Don not short-circuit battery cell Do not connect + and – terminals with metals (such as wire). Do not carry or store the battery cell with metal objects (such as wire, or hairpins). If the battery cell is short-circuited excessive large current will flow and then the generating heat, smoke, rupture or flame will occur. And also, it causes generating heat at metals.
3. Incineration and Heating “Do not incinerate or heat the battery cell” These occur the melting of insulator, damage of gas release vent or safety function, or ignition on electrolyte. Above mentioned matters cause the generating heat, smoke, rupture or flame.
 4. Use nearby Heated Place “Do not use or leave battery nearby fire, stove or heated place (more than 80°C)” In case that separator made of polymer is melted by high temperature, the internal short-circuit occurs in individual cells and then it causes the generating heat, smoke, rupture or flame. In addition, do not use the battery cell under the heated place (more than 80°C).
 5. Immersion “Do not immerse the battery in water or sea water, or get it wet” If the protection circuit included in the battery cell is broken, the battery cell will be charged at extreme current or voltage and the abnormal chemical reaction occurs in it. And then it causes the generating heat, smoke, rupture or flame.
 6. Charge nearby Heated Place “Do Not charge battery nearby the fire or under the blazing sun” If the protection circuit to avoid the danger works under high temperature or it is broken, the battery cell will be charged at abnormal current (or voltage) and abnormal chemical reaction will occur. It causes the generating heat, smoke, rupture or flame.
7. Charger and Charge Condition “Do use the specified charger and observe charging requirement” If the battery cell is charged with unspecified condition (under high temperature over the regulated value, excessive high voltage or current over regulated value, or remodeled charger), there are cases that it will be overcharged or the abnormal chemical reaction will occur in cells. It causes the generating heat, smoke, rupture or flame.
 8. Penetration “Don to drive a nail into the battery, stick it by hammer, or tread it” As the battery cell might be broken or deformed and then it will be short-circuited, it causes the generating heat, smoke, rupture or flame.
 9. Impact “Do Not give battery impact or throw it” The impact might cause leakage, heat, smoke, rupture, and/or fire of cell in the battery. And also if the protection circuit in the battery cell is broken, the battery will be charged abnormal voltage or current, and abnormal chemical reaction might occur. It might cause leakage, heat, smoke, rupture, and/or fire.
 10. Deformation “Do not use the battery cell with conspicuous damage or deformation” It causes the generating heat, smoke, rupture or flame.
 11. Soldering “Do not make the direct soldering on battery cell” As the insulator is melted by heat or the gas release vent (or safety function) is broken, it causes the generating heat, smoke, rupture or flame.
 12. Reverse Charge and Over-discharge “Do not reverse polarity (and terminals)” On charging, the battery cell is reverse-charged and abnormal chemical reaction occurs. And also, there may be case that unexpected large current flows on discharging. These cause the generating heat, smoke, rupture or flame.
 13. Reversed Polarity Use “Do not reverse-charge or reverse-connect” The battery cell has polarity. In case the battery cell is not connected with charger or equipment smoothly, do not force them and do check polarity of battery. If the battery cell is connected to opposite polarity with charger, it will be reverse-charged and abnormal chemical reaction will occur. It causes the generating heat, smoke, rupture or flame.
14. Inappropriate Use For Other Equipment “Do not use battery cell for other equipment” If the battery cell is used for unspecified equipment, it will deteriorate its performance and cycle-life. At worst, abnormal current will flow or battery may generate heat, smoke, rupture or flame.
 15. Leakage “Do not touch leaked battery cell” Do not touch your eyes but wash them immediately, and then see a doctor if leaked electrotype is into your eyes. If pay no attention to your eyes, it will cause eye disease.

Warning！

 1. Mixed Use “Do not use lithium ion battery cell in mixture” Do not use lithium ion battery cell with the primary batteries or secondary batteries whose capacity or kinds or maker is different. If do that, the battery cell will be discharged or charged excessively in use. And it may cause the generating heat, smoke, rupture or flame because of the abnormal chemical reaction in cells.

 2. Ingestion “Keep the battery cell away from babies” Keep the little battery cell out of the reach of babies in order to avoid troubles by Swallowing. In case of swallowing the battery, see a doctor immediately.
 3. Charging Time “Do not continue to charge battery cell over specified time” If the battery cell is not finished charging over regulated time, let it stop charging. There is possibility that the battery cell might generate heat, smoke, rupture or flame.
4. Storage “Do not get into a microwave or a high pressure container” It causes the generating heat, smoke, rupture or flame because of a sudden heat or damage of sealing condition of battery cell.
5. Leakage “Do not use a leaked battery cell narby fire” If the liquid leaks from the battery cell (or the battery gives out bad smell), let the battery cell leave from flammable objects immediately. Unless do that, the electrolyte leaked from battery cell will catch fire and it will cause the smoke, flame or rupture of it.
 6. Rust, Charging color and Deformation “Do not use an abnormal battery cell” In case the battery cell has bad smell or is generated its changing color or deformation or causes something wrong in using (includes charging and storage). Let it take out from equipment or charger and do not use it. If an abnormal battery cell is used, it will generate heat, smoke, rupture or flame.

 Caution！

 1. Use under strong sunshine Do not use or leave the battery cell under the blazing sun (or in heated car by sunshine). The battery cell may generate heat, smoke or flame. And also, it might cause the deterioration of battery cell’s characteristics or cycle life.

 2. Static Electricity The battery pack has the protection circuit to avoid the danger. Do not use nearby the place where generates static electricity (more than 100V) which gives damage to the protection circuit. If the protection circuit were broken, the battery cell would hide danger.
3. Charging Temperature Range Charging temperature range is regulated between 0°C and 40°C. Do not charge the battery cell out of recommended temperature range. Charging out of recommended range might cause the generating heat or serous damage of battery cell. And also, if might cause the deterioration of battery cell’s characteristics and cycle life.
 4. Manual Please read the manual before using the battery cell and keep it after reading.
5. Charging method Please read the manual of specified charger about charging method.
6. First time use When the battery cell has rust, bad smell or something abnormal at first-time using, do not use the equipment and go to bring the battery cell to the shop which it was bought.
7. Leakage If the skin or cloth is smeared with liquid form the battery cell, wash with fresh water. It may cause the skin inflammation.