Supplements for 1st and 2nd Year Chemies

Reading Time: 4 minutes

Hey 2nd Yearites . !!  As you are in 4th sem so first of all you might be thinking  what chemical engineering is…. We are not definitely studying it the way we used to study chemistry in XI or XII standard,instead of that we are with subjects like Electrical Technology, TMMD, Solid mechanics. I’ll tell you why these subjects are important. As chemical engineer you will be able to come up with technical solutions for problems and issues in relation to process and product technology. In finding these solutions, chemical engineers work closely with experts from other specializations, taking into account the related economical, social, environmental and ethical aspects of the problem they’re dealing with. To understand it let us see one practical situation wherein you have task to build up a transportation pipeline from point A to point B  and no qualified person is with you to help except one or two labourers. Your area of concern will be : 1) Angle of elevation of point A and point B from horizontal. 2) Diameter,length of pipe and which type of joints should be there? — So here comes Theory of machines and machine designing. 3) From what material pipe is to be made ? and what are the possibilities of failure of such a  structure? If pipeline is to be made underground then the nature of soil needs to be understood to avoid corrosion problems— So here comes Chemical Engineering Materials. Finally let’s say you have carefully made all arrangements and the pipeline is ready to use. And as you switch on the pump, you may not see the fluid coming out from the pipe!!Then what will you do??? What is the problem??? Problem was that you may not used proper motor which will provide you exact power or you have purchased correct HP motor but it is consuming more power, then you will go and see whether my motor is delta or star connected because every connection has its advantages and disadvantages. So if you have studied electrical engineering basics then you would have easily identified the problem.

  • Please don’t take any subject lightly or for the sake of getting marks. Strictly speaking what I think  from my experience is that an engineer should have the know of  basics of all disciplines of engineering. Now you may ask is coding and programming is going to help a chemie?? The answer is yes, because chemical process calculations are not as simple as solving an two variable equation and finding the answers. Practically any chemical  process or  even a small unit operation will have ‘n’ no. of variables so how you can solve them. So we need simulation software to handle these large no of variables. Now if you have basic “funda” clear in your mind that how it was designed and programmed.. You can handle the software much better than your colleague. But again I am not saying that you should be ‘phoodu’ in programming but basics are compulsory.
  • So, Chemical or process engineering is an interdisciplinary science comprising elements of mechanical Engineering, chemistry and technical physics.
  • The difference between chemical Engineering and process engineering lies in the emphasis of the degree course: while chemical engineers concentrate mainly on chemical processes, process Engineers deal primarily with the plants needed for this, their design and technical solution.
  • For General Chemical Technology (GCT) please watch you tube animation videos, NPTEL lectures. Also you can distribute these topics among your friends and then have a discussion for e.g. one can prepare about paper and pulp industry , other one on sugar industry and discuss among themselves.

I hope you are clear what are the application and importance of these subjects in the life of chemical engineer.

  • For first yearites : Observe the chemical processes occurring in day to day life and analyze them. See corrosion problems , how thermodynamics is playing in your home kitchen, analyze how propulsion systems works , analyze how energy sources like batteries, fuel cells, solar cells works.
  • Study alternate sources of energies such as bio diesel ( Jatropha seeds).Go through some basic outline of industries such as:Sugar industry, paper and pulp industry, soap and detergent industry….etc.
  • If possible visit as many industries as possible.
  • At the end of first year try to learn Microsoft Excel Software as much you can and C programming language in summer vacations.


  • For second yearites.. We dont have core chemical engineering subjects in 2nd year… So in 2nd year have active  participation  in techfests of various colleges; this will give you experience, direction , boost up your confidence and   will definately gives practical knowledge which helps when you will study core subjects such as (HTO, MTO, Thermo, CRE..etc)
  • You can participate in events like chemical car competition and chemistry related quizzes in 2nd yearand then in 3rd year you can participate in heat exchanger event …(I am saying this because there is a separate topic on heat echanger in 5th semester,so it is better to participate in this event later on in 3rd year.) … Do as per your interest.
  • Read magazines these are available in library, watch NPTEL lectures they are very good.
  • There are some free online courses available online these are given by profs of MIT , Harvard, Oxford, Stanford.. So make use of them. Most recommended courses are EDX and Stanford university online course.
  • My advice to you all is that don’t do industrial training in 2nd year.Instead  go to your seniors, profs and work under them  and learn as much you can from them. The best places for summer training  in chemical engineering some are: IITs, IISC , ISER, NCL, ICT, CSMCRI etc and in Private colleges we have very good Nanotechnology Lab at DDIT college in Nadiad. and in our college itself we have summer training programme so apply for that .

Some preferred courses: EDX

  1. our energetic earth
  2. Introduction to water treatment 
  3. Solar energy
  4. Introduction to solid state chemistry
  5. Thermodynamics
  6. Introduction to Drinking Water Treatment


  1. Solar: Solar Cells, Fuel Cells and Batteries.
  2. Reservoir Geomechanics

Basics of Solar Cell Technology

Reading Time: 8 minutes

Solar energy has enormous potential and it is highest among all the available sources of energy available whether it is renewable or non renewable sources. It is free, it is renewable and it is clean source of energy.

Now to begin, let’s start with one practical situation:

Assume that you have told to set up a solar power plant in India and you have given sufficient fund and land.  So what you will do??!!

Following are the points which you should think:

1) first you have to find a place in India where maximum solar power is hitting (Solar Ir-radiance ).solar-energy-distribution-india-map


2)      Lets say you have decided to put solar power plant in Gujarat. Now in Gujarat you have to see at what location exactly what amount of solar energy is hitting per square area.

Now we will  understand how it is calculated:


Any body which is above 0K  temperature will emit radiation according to planks law which is

given by:

download (1)

Above expression is for a body which is at particular  temperature and emitting radiation of a particular wavelength  but as we know body is  emitting radiations of all wavelengths from 0 to infinity. So we have to integrate that expression E(ƛ)d(ƛ) from o to infinity to find total emissive power emitted by the body.

Similarly consider sun as the source of solar radiations and earth is intercepting those radiations .the amount of solar radiation hitting on some area of earth will depend upon solid angle multiplied total emissive  power of sun.



So by doing integration of solar irradiance expression (emissive power) multiplied by solid angle of whole earth considering no atmosphere we will get a fix value known as solar flux and that is equal to 1367 W/m2.

Solar flux: The total energy flux (energy per time per area) incident on a unit area perpendicular to a beam outside the Earth’s atmosphere.

Air mass factor(AM): Air mass factor gives you idea about the relative position of sun w.r.t. to earth.

AM = 1/ CosƟ , where Ɵ equal to angle from vertcle line when sun is directly overhead to us.

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For e.g.  AM 1.5 = 1/CosƟ  => Ɵ=48.2*

AM0 means no atmosphere.

Now you have to calculate the solar flux which is hitting on your area in Gujarat. What you will do you will first of all find latitude of that area.


After finding latitude we have to multiply that solar power density which is coming parallel to plane of equator with cosine of latitude because we want those photons which are hitting perpendicular to our solar cell.


3) So we have decided the location of power plant by calculating the exact solar flux hitting that area.


4) Now what next?? Before installing the solar panels we have to understand how solar cell works:


  • The main part of solar cell is p-n junction. When p type and n type material are joined there is formation of space charge region/depletion region and It stays localized at the P-N junction and an electric field has been created.
  • If the solar cell is put in the sun, photons will strike the surface of the Silicon and pass their energy on to electrons. A typical photon can eject one electron from its nucleus creating a free electron and a vacancy. These free electrons will feel the effect of the electric field. They are pushed towards the junction on the N-side and away from the junction on the P-side. Likewise, the vacancy, which has a net positive charge, will be pulled towards the junction on P-side and pushed away from it on the N-side.
  • So there is current flowing from p type to n type material. This current is known as photo induced current and denoted by IL



  • This photo induced current generates voltage around load, but this voltage generation will also forward biased our p-n junction and there is another current  flows  through load known as forward biased current IF . so we will have net current I=I– IF   flows through our load.
  • Current vs voltage characteristics of our p-n junction is shown below:r3r
  • We can see from the graph that there is point where we are getting maximum power. so our aim is to find that point. This can be easily calculated by simple differentiation technique.
  • If still not clear , watch this video:



  • Efficiency is most important thing to any type energy system. We have reached maximum efficiency of  44% in case of solar cell.(search and find what are the efficiency of other sources of energy)
  • How to find efficiency of our solar cell???…


To find efficiency we have to first follow above procedure and calculate Jmax and Vmax


Above numerator term is Jmax* Vmax

Denominator is solar power denoted by Ps   at some AM value.

For e.g. Ps value at AM= 1.5 means

1367W/m2 *cos(41.8) =1000 W/m2

  5) After learning basics of solar cell, let’s build solar cell. Before we discuss the components of real solar cell,( just think what can be most imp building blocks of solar cell !!!  )

Following are the main components of solar cell:

  • P-n junction : Every p-n system is characterized by its unique band bap( ΔEg) or    forbidden energy gap.
  • Anti Reflecting Coating:  If ray of light incident on any surface ,some part is reflected and some part is transmitted.  we have to have maximize the transmittance .so we are applying the layer of such a material whose refractive index is the geometric mean of mediums which are above and below of anti reflective coating.


  • Glass: glass is used for two purposes first to concentrate the beam of light secondly to have self cleaning property so that any dust particle or any organic impurity can be washed off easily.


So to have self cleaning property of glass, two methods are used:


  1. We can coat a hydrophobic layer on glass which will make the contact angle for water – glass system to very large and consequently a spherical drop of water will from, which rolls down due to gravity taking away dust .
  2. We can coat a super hydrophilic coating on glass e.g. coating of TiO2. The glass cleans itself in two stages. The “photo catalytic” stage of the process breaks down the organic dirt on the glass using ultraviolet light and makes the glass super hydrophilic (normally glass is hydrophilic. During the following “super hydrophilic” stage, rain washes away the dirt, leaving almost no streaks, because water spreads evenly on super hydrophilic surfaces
  • Conducting wires: these are used to connect small -small solar cells into series and parallel.

Watch the below link to know how solar cell is manufactured. This video is of company- ‘’Sun Tech Power”.

6) Now you have installed solar cells and production is started. Now you have to know what maintenance is required and what are the factors which affects the performance of my cell.

Following are the factors which affects the efficiency of solar cell:

  • Loss of photons which are below the band gap:

This loss is highest among all losses. We know that light which is hitting contains photons of various energies but out of 100% photons only 30% are capable of generating current because a p-n junction is fixed for photon which have energy equal to band width rest are of no use.


There are multiple p-n junction kept one below the another and of variable band gaps.


  • Loss of energy from relaxation of carriers to band edges:

To understand this lets go to atomic level of p type material. This material when irradiated with some light electron will make jump from valence band to conduction band. Now this electron from the conduction band of p type goes to conduction band of n type via space charge region and during this journey electron losses its potential energy and relax at the band edges which results in dissipation of heat   as shown in fig:



  • Resistance losses (shunt and series resistances) which will decrease Voc and photo current:

This is the second largest loss after loss of photons. Generally two types of resistances are there series and shunt .These resistances arises because of:

Series: 1. Resistence of connecting wires.

2. Contact resistances.

Shunt (parallel) : These are mainly due to impurities phases lying from  p type to  n type material .

  •  Junction recombination: electrons which are generated by light, some of them will lost while going through depletion region.
  • Optical losses :
  • Dirt accumulation on the glass :
  • Effect of temperature:  There is optimum range of temperature in which solar cell works efficiently ,Increasing temperature will decrease the cell efficiency.
  • Carrier recombination at defects: This effect is due to grain boundaries resulting in decrement of light current.

7) At last these are materials used in solar cell technology with their efficiencies:



In India we have largest solar park of Asia at Charanka village, Patan district, Gujarat. There is video on it :


Stanford university free online course: “solar cell, fuel cell and batteries”


Applications & Basics of Bucky Paper

Reading Time: 5 minutes

Buck paper is an arrangement of carbon nanotubes in some desired fashion and orientation or we can say buckypaper is a macroscopic aggregate of carbon nanotubes (CNT’s).

The specific properties of bucky paper depends upon arrangement of CNTs . These properties include :

1)EMI ( electro- magnetic interference) Shielding.

2)Strength .


4)Thermal stability.

By adding the resin and the hardener to the buckypaper and then curing it in a specific temperature and pressure, the buckypaper composite will be produced.


Fig 1.                                                                              Fig 2

Fig1 shows picture of bucky paper composite.

Fig 2 shows SEM image of bucky paper.

Now before going in detail about bucky let us talk about its building block –CNT . We will learn what it is , its types , its preparation methods and properties.

Carbon Nanotube

Carbon is having 3 forms of allotropes: graphite, diamond and fullerene, and if we talk about graphene it has two dimensional hexagonal sheets one above the other.


So if we roll  that two dimensional sheet we get CNT is a tubular form  with diameter as small as 1nm and length in few nm to microns.Picture4

The way that graphene is rolled up drastically change physical properties and we get different types of nanotubes.

We can define the nano tube in terms of the equation : Ch = n â1 + m â2,

Ɵ is Chiral Angle with respect to the zigzag axis and a1, a2 are chiral vectors.

The coefficients n, m define what kind of nanotube it is. For e.gPicture5

n= m armchair nanotube

m=0  zig-zag nanotube

n ≠ m chiral nanotube

and under some conditions such as n-m =3r where r= 0,1,2..we get metallic nanotubes otherwise semiconducting nanotubes.


Picture61So we can say that- The values of n and m determine the chirality, or “twist” of the nanotube. The chirality in turn affects the conductance of the nanotube, it’s density, it’s lattice structure, and other properties. A SWNT is considered metallic if the value n – m is divisible by three. Otherwise, the nanotube is semiconducting. Consequently, when tubes are formed with random values of n and m, we would expect that two-thirds of nanotubes would be semi-conducting, while the other third would be metallic.

Types of carbon nanotubes: 

A)Single walled carbon nanotube                 B) Multi walled carbon nanotube



MWCNTS are concentric nanotubes.



Preparation methods:

As CNT is a thin two dimensional graphene sheet we will first learn how this grapheme layer is prepared. The simplest method to produce  graphene layer is chemical method.


1)Take graphite powder cooked it in acid (cons H2SO4) with an oxidizing agent (cons  HNO3), thus will give graphite oxide.

2) Graphite oxide will then reduced to give graphene.

3) now this graphene is in solution form , put this solution on any substrate we get graphene layer.

Fig3 below shows schematic procedure of chemical method.


Second method most important method is Arc Discharge method.


This is the most common and perhaps easiest way to produce carbon nanotubes as it is rather simple to undertake. In this method two carbon rods placed end to end, separated by approximately 1mm, in an enclosure that is usually filled with inert gas (helium, argon) at low pressure (between 50 and 700 mbar) as shown in Figure 4. A direct current of 50 to 100 A driven by approximately 20 V creates a high temperature (~4000K) discharge between the two electrodes. The discharge vaporizes one of the carbon rods (anode) and forms a small rod shaped deposit on the other rod (cathode).

Third method is Chemical Vapour Deposition (CVD):

In short we can say that here we have a chamber in which substrate + catalyst is present and gas(carbon source) comes in and there will be:


  • Adsorption
  • Dissociation of hydrocarbon.
  • Dissolution and saturation  of C atoms in metal .
  • Precipitation of Carbon.
  • Picture2

Properties of CNT:

  • Mechanical : Young’s modulus of the single walled carbon nanotubes (SWCNTs) can be as high as 2.8-3.6 TPa and 1.7-2.4 TPa for multiwalled carbon nanotubes (MWCNTs) which is approximately 10 times higher than steel, the strongest metallic alloy known.

Application:  the high stiffness and strength combined with low density implies that nanotubes could serve as ideal reinforcement in composite materials and provide them great potential in applications such as aerospace and other military applications.

  • Electrical: They can be can be metallic or semiconducting depending on their structure and their band gap .  Theoretically, metallic nanotubes having electrical conductivity of 105 to 106 S/m can carry an electric current density of 4 × 109 A/cm2 which is more than 1000 times greater than copper metal .

Application:  So the high electrical conductivity of CNTs makes them an excellent additive to impart electrical conductivity in otherwise insulating polymers. Used in fuel cell technology.

  • Thermal: SWCNT has a room-temperature thermal conductivity along its axis of about 3500 W m−1 K−1 and MWCNTs have a peak value of ~ 3000 W m−1 K−1 at 320 K; compare this to copper, a metal well-known for its good thermal conductivity, which transmits 385 W m−1 K

Application: thermal management applications, either as “heat pipes” or as an alternative to metallic addition to low thermal conductive materials,heat sinks that would allow computers and other electronic equipment to disperse heat more efficiently than is currently possible


Preparation of Bucky paper


Now we have CNT’s ready with us in both forms SWCNT’s and MWCNT’s. We have to put these nanotubes in some desired fashion to form bucky paper,figure shown below clearly explains the procedure to do it:



This is just the basics of bucky paper or CNT, if someone have to study in detail their is an excellent video  lecture from Prof C.N.R Rao, check it :

Basics of Cells & Battries

Reading Time: 7 minutes

Cells or Batteries are broadly classified into two four broad categories:

  • Primary cell
  • Secondary cell
  • Reserve cell
  • Fuel cell


Let us start with basic definition of these cells:

Primary cell:

  1. primary cell or battery is one that cannot easily be recharged back.
  2. Generally these cells contain electrolyte in the form of solid powdered state and that’s why these are also known as DRY CELLS.
  3. Cells contain electrochemical reactions which are non –reversible.
  4. These are having very low self discharge rate known as charge retention factor. Factors affecting self-discharge extent include: anode and cathode preparation course, electrolyte nature and concentration, and battery storage temperature and time, among which battery self discharge greatly depends on temperature.
  5. Examples: Zn–MnO2 cell which is most commonly used battery. This type of battery is available in different sizes- AA, AAA, C, D etc.

We discuss later on what is the difference in between them in terms of electrochemistry.


Let us understand electrochemistry of Zn –MnO2 cell:


Understanding electrochemistry of any battery always divides the cell into separate anode region, cathode region, electrolyte used and separator material which separate anode and cathode.

So, here we have Zn metal at anode which reacts with electrolyte ammonium chloride as follows:

Zn(s) + 2OH(aq) → ZnO(s) + H2O(l) + 2e [e° = 0.76 V]

Emf(Ox) = 0.76 – RT/2F ln([Zn0]/[OH-]^2)……nernst equation


At  cathode MnO2 is there which will reat with two e-‘s on cathode eletrode surface i.e.

2MnO2(s) + H2O(l) + 2e → Mn2O3(s) + 2OH(aq) [e° = +0.5 V]

Emf (Red) = 0.5 – RT/2F ln ([Mn2O3]/[MnO2^2])


Add both anodic and cathodic half cell reactions we get:


Zn +MnO2 –>ZnO2 + Mn2O3


Emf total = Emf (ox) + Emf (red)

= +1.56 –RT/2F ([Mn2O3][ZnO2]/[MnO2])

The above process is discharge of cell but if we consider discharge of a battery we have to reverse the above reactions but thermodynamically this process is infeasible, and that’s why we cannot charge primary cells.

Secondary cell:

  1. Electrochemical reaction occurring in reversible in nature ,therefore we can recharge them
  2. e.g. : lead–acidnickel cadmium (NiCd), nickel metal hydride (NiMH), lithium ion(Li-ion), and lithium ion polymer (Li-ion polymer).

Lead Acid Battery

Lead–acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable batteries. This is most widely used commercial battery used in    automobiles and heavy electronic devices because of its high current rating.

Let’s understand the mechanism of lead acid batteries:

Negative plate reaction: Pb(s) + HSO−4(aq) → PbSO4(s) + H+(aq) + 2e-

Positive plate reaction: PbO2(s) + HSO−4(aq) + 3H+(aq) + 2-e → PbSO4(s) + 2H2O(l)


Overall reaction: Pb(s) + PbO2(s) + 2H2SO4(aq) → 2PbSO4(s) + 2H2O(l)



Applying Nernst equation at room temperature for this case we get 2v.

I.e. Per cell voltage is 2v.Therefore 6 cells are stacked together to form 12v battery having 13.9 amp-hours per kg.


 Similarly we can think of Lithium ion battery, they are one of the most popular types of rechargeable battery for portable electronics, with one of the best energy densities, and only a slow loss of charge when not in use.




Positive electrodes: LiCoO2- =   Li1-x CoO2 + xLi + xe-
Negative electrodes:  C+xLi+xe-  =   CLix

Battery as whole:    LiCoO2 + C  =   Li1-x CoO2+CLix
<– charging

  • During discharge, lithium ions Li+ carry the current from the negative to the positive electrode, through the non-aqueous electrolyte and separator diaphragm.
  •  Picture4Picture5
  • Pure lithium is very reactive. It reacts vigorously with water to form lithium hydroxide and hydrogen gas. Thus, a non-aqueous electrolyte is typically used, and a sealed container rigidly excludes water from the battery pack.



Now next is Reserve batteries :

  •  These batteries are working as normal batteries but cell is inactive (dead) until and unless cell certain condition is not fulfilled.
  •  These batteries are used in radio sondes, missiles, projectile and bomb fuzes, and various weapon systems. Generally these are used for military purposes.
  •  Another example is zinc-air batteries where the cell is sealed until use: a tab is removed to admit air and activate the cell.
  •  It can be activated by: Addition of water, Addition of electrolyte, Introducing gas into the cell, heating solid electrolyte (solid-oxide fuel cell) so that it becomes conductive and there may be many other ways by which we can activate these cells.

Fuel cell

fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent.

Hydrogen is the most common fuel, but hydrocarbons such as natural gas and alcohols like methanol are sometimes used.

Fuel cells are different from batteries in that they require a constant source of fuel and oxygen to run, but they can produce electricity continually for as long as these inputs are supplied. For e.g. in Zn-Air fuel system if continuous supply of O2 at cathode and simultaneously removal of ZnO (by product) from anode we can get power continuously.


For e.g.- Hydrogen fuel cell, Microbial fuel cell etc.

So, until now we have discussed types of batteries, let us now understand basic things which very essential to understand any battery :


Terminology used in Electrochemistry:

1) Ampere hour: It is the amount of current supplied by the battery in one hour.

e.g.: 30mAhr means when connected to a load of rating 5 mAhr then load will work for 6 hrs .When cells are stacked together then ampere hr rating is return of per kg of cell.

2) Energy Density:  It is how much energy can be stored per unit volume or mass of a battery. It is expressed in joules per unit mass. MJ/kg

3) Power Density: It is basically how quickly energy is taken out from battery.It is expressed in kW/kg

4) Self discharge rate: it is process in which cell stored internal energy is decreased. self- discharge in a battery occurs is dependent on the type of battery, state of charge, charging current, ambient temperature and other factors.

Among rechargeable batteries, lithium batteries suffer the least amount of self-discharge (around 2–3% discharge per month), while nickel-based batteries are more seriously affected by the phenomenon (nickel cadmium, 15–20% per month; nickel metal hydride, 30% per month).



Now let us understand on what factors cell voltage, internal resistance depends:

Cell Parameters


1)     CELL VOLTAGE : it depends upon concentration of chemicals.

  • E call= Rt/nF*ln[k]….Nernst equation
  • Where k depends upon concentration of reactants and products. Now when cell discharges reaction will go in forward direction till equilibrium is reached.(le chatlier principle).Then cell is considered as dead. Now we have to recharge the cell to increase [] of product side.

For e.g. we have AA and AAA type of dry cell, so what is the difference in between them???


  • Diameter of AA battery is more AAA battery.
  • Both are having same voltage output as voltage output does not depends upon size of cell but depends upon concentration of electrolytes.
  • The only difference is of current rating which is less in AAA batteries as compared to AA. e.g.: AA, AAA, LITHIUM BATTERY, ALKALINE BATTERIES ETC.(’AA ’ means 50.5mm x 13.5mm.)



2)     Internal Resistence


  •   Resistance =ρ *l/a where l is length between electrodes and ‘a’ is surface area of electrodes.
  •  Now this constant ρ depends upon electrolyte concentration. In 90% batteries electrolyte work as catalyst but in few cells electrolyte is consumed .As electrolyte becomes less and less conductive .so result is increased resistivity of cell.

3)     Polarization curve: It is plot between voltage outputs of the battery versus % discharged.

Figure shown here is the polarization curve for most commonly used batteries. We can see here initial voltage drop then it remains constant and then finally voltage drops fast.






Other interesting stuffs:

The battery terminals are generally labeled as : + , – , T , and D or Do.
T is connected to an internal temperature sensitive component ( thermistor) . This is to prevent overheating of the battery so it is very important on safety point of view
D or Do is a newly introduced contact. It is a data line which allows Smartphone and battery to exchange information about current, voltage, temperature, residual battery capacity etc…. It has been introduced to improve % remaining battery capacity readings.






CEV - Handout