Presentation about Batteries in Electrical Technology.pptx

Electrical technology'

1. Batteries

2. 2 CONCEPT OF ELECTROCHEMISTRY Electrochemistry is the study of chemical application. Electrochemistry deals with the interactions between electrical energy and chemical energy. These interactions are of two types Conversion of electrical energy into chemical energy Conversion of chemical energy into electrical energy

3. 3 Electrical Conductors: Substances which allows electric current through it. Ex: Metals, graphite,fused salts,aqueous solutions of acids, bases & salts. Types of conductors 1)electronic conductors 2)electrolytic conductors Non conductors or Insulators: Substances which does not allows electric current through it. Ex: Rubber, paper ,dry wood ,etc

4. METALLIC CONDUCTORS: Metallic conductors conduct electricity due to the movement of electrons from one end to another end. In a solid, the electrical conduction involves the free movement of electrons in the metallic lattice, without any movement of the lattice atom; this type of conduction is called metallic conduction. In metallic conductors, the electricity is carried by the electrons, the atomic nuclei remaining stationary. : These conductors are further sub classified in to three types. A. Good conductor B. Semi- conductor C. Non- conductor or Insulator

5. Good conductor: It is a substance, which conducts electricity fully and freely. EX: Metals like Copper , Aluminum, and Iron.

6. Semi- conductor: It is a substance, which partially conducts electricity. EX: Silicon, Germanium.

7. 7 Substances in their fused form or in aqueous form allow the passage of current undergoing a simultaneous chemical transformation are called electrolytes and the conduction as the electrolytic conductance Reciprocal of resistance is called as conductance C = 1/ R Units = mho Resistance (R) of a conductor is directly proportional to it’s length (l)& inversely proportional to area of cross section (a) R α l/a Electrolytic conduct ors

8. Metallic conductors 1. Conductance is due to the flow of electrons. 2. It does not result any chemical change. 3. Metallic conduction decreases with increase in temperature. 4. It does not involve any transfer of matter Electrolytic conductors: 1. Conductance is due to the movement of ions in a solution. 2. Chemical reactions take place at the electrodes. 3. Electrolytic conduction increases with increase in temperature. 4. It involves transfer of matter. 8 Difference between metallic and electrolytic conductors

9. 9 Specific conductance: Specific conductance is the conductance of all the ions that are present in 1 ml solution. Units; ohm -1 cm -1 . Equivalent conductance: Equivalent conductance is the conductance of total ions present in a solution containing 1 g equivalent of electrolyte. = Units:ohm -1 cm 2 equiv -1 ^v =

10. 10 Molar conductance: Molar conductance is the conductance of all the ions of 1 mole of electrolyte present in a solution. Units: = ohm -1 cm 2 mole -1

11. 11 EFFECT OF DILUTION: Generally conductance depends on three factors 1.number of ions 2.charge of ions 3.mobilityof ions As the dilution increases more, the electrolyte ionises more &specific conductance decreases. Equivalent &Molar conductance increases with dilution

12. 12 Electromotive Force is the difference of potential, which causes the current to flow from an electrode at higher potential to the one of lower potential. E cell = E (right) - E (left) E cell EMF of the cell. E right reduction potential of right hand side electrode. E left reduction potential of left hand side electrode. ELECTROMOTIVE FORCE

13. 1.Potentiometric titrations can be carried out. 2. Transport number of ions can be determined. 3. P H can be measured. 4. Hydrolysis const. can be determined. 5. Solubility of sparingly soluble salts can be found. 13 Applications of EMF measurement :-

14. 14 It is a cell in which chemical energy is converted to electrical energy. This cell consists of two half cells 1)Anodic half cell 2) Cathodic half cell At anodic half cell, oxidation takes place At cathodic half cell, reduction takes place GALVANIC CELL

15. 15 The following reactions take place in the cell. At Anode: Zn → Zn +2 + 2e - (oxidation or de- elecronation ) At cathode: Cu +2 + 2e - → Cu ( Reduction or electronatioin ) The movement of electrons from Zn to cu produces a current in the circuit. The overall cell reaction is: Zn +Cu +2 → Zn +2 +Cu The galvanic cell can be represented by Zn/znso 4 //cuso 4 /cu

16. 16 An electrode of known potential is called reference electrode. Hydrogen electrode is the earliest primary reference electrode. The secondary reference electrodes discussed here are 1)Calomel electrode 2)Quinhydrone electrode REFERENCE ELECTRODES

17. 17 Types of electrodes Primary & secondary reference electrodes : Standard hydrogen electrode(SHE): It is a primary reference electrode. The emf of such a cell is arbitrarily been fixed as zero. construction: It consists of a small platinum electrode coated with platinum black immersed in a 1M solution of H + ions maintained at 25 c. Hydrogen gas at one atmosphere pressure enters the glass hood and bubbles over the platinum electrode. The H 2 gas at the platinum electrode passes into the solution forming H + ions & electrons. H 2 2H + +2e -

18. 18 By convention the standard electrode potential of hydrogen electrode when the hydrogen gas passed at one atmosphere pressure is bubbled through a solution of hydrogen ions of unit concentration is orbitarily fixed as zero. Nernst equation: At latm E pt, H 2 / H + = E pt, H 2/H+ - 0.059 =E pt, H 2 /H + + 0.059 p H log a H +

19. 19 Depending on a half cell to which it is attached hydrogen electrode can act as a cathode or an anode. But in the given figure hydrogen electrode is connected to copper electrode & it act as anode ,when it is acting as anode ,oxidation takes place. 1/2H 2 (g)(1atm)  H + (1M)+e

20. 20 The calomel electrode consists of a glass tube having two side tubes. A small quantity of pure mercury is placed at the bottom of the vessel and is covered with a paste of Hg and Hg 2 Cl 2 . KCl solution of known concentration is filled through side tube, Shown on the right side of the vessel. The KCl sol. is filled in the left side tube which helps to make a connection through a salt bridge with the other electrode, which potential has to be determined. A ‘pt’ wire is sealed into a glass tube as shown in the fig which is in contact with Hg. When the cell is set up it is immersed in the given solution. Calomel electrode

21. 21 The electrode potentials of calomel electrode of different concentrations at 25 c are 0.1 M KCl / Hg 2 cl 2 (s) / Hg,pt  0.33v 1M KCl / H g 2 cl 2 (s) / Hg,pt Saturated kcl /Hg 2 cl 2 (s) /Hg, pt The corresponding electrode reaction is Hg 2 Cl 2 + 2e -  2Hg + 2cl - 0.28v  0.24v 

22. 22 Glass electrode is one of the type of ion selective electrode. (ISE). It is is made up of glass tube ended with small glass bulb sensitive to protons. Glass electrode The tube has strong and thick walls and the bulb is made as thin as possible. Inside of the electrode is usually filled with buffered solution of chlorides in which silver wire is covered with AgCl is immersed. The pH of internal solution can be varies. In this electrode, active part of electrode is the glass bulb. The surface of the glass is protonated by both internal and external solution till equilibrium is achieved. Glass electrode

23. 23 Both sides of the glass are changed by the absorbed protons. And this charge is responsible for potential difference. This potential is directly proportional to the pH difference between the solutions on both sides of the glass. Glass electrode work in the pH range of 1-12 the glass electrode may be represented as Ag, AgCl / Hcl (0.1N) / glass / H + (unknown) Here Ag/ AgCl acts as internal reference electrode.

24. 24 Glass electrode diagram

25. Nernst studied the theoretical relationship between electrode reaction and the corresponding cell e.m.f . This relationship generally Known as Nernst equation. Consider a galvanic cell aA + bB  cC + dD. Where a,b,c,d represents no. of moles respectively at equilibrium. The Nernst eq ’ for the cell is written as 25 Nernst equation -

26. 26 In the above eq ’ R= 8.314 J/K. T=298K, F=96, 500 columbs . By substituting the values in the eq ’ - 2.303 - 0.0591 Applications: 1.It can be used to study the effect of electrolyte concentration on electrode potential. 2.the ph of the solution can be calculated from the measurement of emf and Nernst equation. 3.Nernst equation can also be used for finding the valency of an ions or the number of electrons involved in the electrode reaction

27. When the metals are arranged in the order of increasing reduction potentials or decreasing oxidation potentials which are determined with respect to one molar solutions of their ions and measured on the hydrogen scale, along series or list, resulted is called electrochemical or galvanic series. The higher a metal is in the series, the greater is its tendency to be oxidized. Applications : 1. relative corrosion tendencies of the metals& alloys. 2.relative ease of oxidation or reduction of metals. 3.replacement tendency of metals. 27 Electrochemical series

28. 28 STANDARD REDUCTION POTENTIAL

29. 29 Batteries & Fuel Cells A history in pictures

30. 30 Luigi Galvani “Animal Electricity Alessandro Volta 1771-1800: The Galvani-Volta Controversy

31. 31 1800: The First Battery (Voltaic Pile) 1801: Volta presenting his battery to Napoleon

32. 32 1821: The First Electric Motor 1835: The First BEV (Battery Electric Vehicle) Michael Faraday Sibrandus Stratingh

33. 33 Sir William Grove 1839: First Fuel Cell (Grove’s “Gas Battery”)

34. 34

35. 35 They are electrochemical cells connected in series Batteries are Store houses of electrical energy They are used as a source of direct electric current at constant voltage. They are classified into two types i ) Primary cell ii) Secondary cell BATTERIES

36. 36 Primary Batteries: These are non rechargeable & are meant for single use& discarded after use. Secondary Batteries: Voltaic cells whose electrochemical reactions can be reversed by a current of electrons running through the battery after the discharge of an electrical current. A secondary battery can be restored to nearly the same voltage after a power discharge.

37. 37 Primary cells Secondary cells These are non-rechargeable and meant for a single use and to be discarded after use. Cell reaction is not reversible. Cannot be rechargeable. Less expensive. Can be used as long as the materials are active in their composition. Eg : Leclanche cell, ‘Li’ Cells. These are rechargeable and meant for multi cycle use. Cell reaction can be reversed. Can be rechargeable. expensive. Can be used again and again by recharging the cell. Eg ; Lead- acid cell, Ni- cd cells. Differences between Primary and secondary batteries:

38. 38 In this cell the reactions are irreversible It is also known as Dry cell Anode- Zinc container Cathode- Carbon rod Anode reaction Zn→ Zn 2+ +2e - Cathode reaction 2NH 4+ +2MnO 2 +2e - → Mn 2 O 3 +2NH 3 +H 2 O Cell reaction 2MnO 2 +2NH 4 Cl+Zn→ Zn(NH 3 ) 2 Cl 2 + Mn 2 O 3 +H 2 O PRIMARY CELL OR LECLANCHE CELL

39. 39 Anode reaction Pb+HSO 4 - → PbSO 4 +H + +2e- Cathode reaction PbO 2 +HSO 4 - +3H + +2e - → PbSO 4 +2H 2 O Cell reaction Pb+PbO 2 + 2H + +2HSO 4 - → 2PbSO 4 +2H 2 O Lead Storage battery

40. 40 Pb +PbO 2 +H 2 SO 4  PbSO 4 (s)+H 2 O Low self-discharge 40% in one year (three months for Ni- Cd ) No memory Cannot be stored when discharged Limited number of full discharges Danger of overheating during charging Lead Acid Recharging

41. 41 Applications 1.Automobile and construction equipment. 2. Standby / backup system. 3. For engine batteries Advantages :- Low cost, long life cycle, Ability to withstand mistreatment, perform well in high and low temperature .

42. 42 4. Lithium-ion battery (Li-ion Battery) Li-ion batteries are secondary batteries. The battery consists of a anode of Lithium, dissolved as ions, into a carbon. The cathode material is made up from Lithium liberating compounds, typically the three electro-active oxide materials, Lithium Cobalt-oxide (LiCoO 2 ) Lithium Manganese-oxide (LiMn 2 O 4 ) Lithium Nickel-oxide (LiNiO 2 )

43. 43 Principle During the charge and discharge processes, lithium ions are inserted or extracted from interstitial space between atomic layers within the active material of the battery. Simply, the Li-ion is transfers between anode and cathode through lithium Electrolyte. Since neither the anode nor the cathode materials essentially change, the operation is safer than that of a Lithium metal battery. The chemical reaction that takes place inside the battery is as follows, during charge and discharge operation:

44. 44 Li-Ion battery Principle Li- ion Electrolyte

45. 45 Advantages They have high energy density than other rechargeable batteries They are less weight They produce high voltage out about 4 V as compared with other batteries. They have improved safety, i.e. more resistance to over voltage. No liquid electrolyte means they are immune from leaking. . Fast charge and discharge rate Disadvantage They are expensive They are not available in standard cell types.

46. 46 Applications The Li-ion batteries are used in cameras, calculators They are used in cardiac pacemakers and other implantable device They are used in telecommunication equipment, instruments, portable radios and TVs, pagers They are used to operate laptop computers and mobile phones and aerospace application

47. 47

48. 48 The cell that converts energy of combustion of fuels like Hydrogen, Methane to electrical energy. Fuels are usually gas or liquid, with oxygen as the oxidant..… Different fuel cells are The direct conversion of chemical energy to electrical energy has 100%. The cell representation is as follows. Fuel/electrode//electrolyte//electrode//oxidant Types of Fuels: 1.Hydrogen – Oxygen Fuel cell 2.Methanol –Oxygen fuel cell FUEL CELLS

49. 49 Large weight and volume of hydrogen gas fuel storage system High cost of Hydrogen gas, technological advances should bring the cost down Lack of infrastructure for distribution and marketing of Hydrogen gas. Most basic fuel cells suffer from carbon di oxide leakages and should be prevented from entering the cell and reacting with the electrolyte. LIMITATIONS OF FUEL CELLS

50. 50 Hydrogen-Oxygen or Alkaline fuel cell In this fuel cell, electrolyte is 25-30% aqueous KOH.This cell make use of high purity of hydrogen as fuel &oxygen as oxidant. The reaction between H 2 -O 2 takes place to produce water &excess electrons produces the electric current .

51. 51 Reactions: At anode:2H 2 +4OH -  4H 2 O+4e - At cathode: O 2 +2H 2 O +4e -  4OH - Net reaction: 2H 2 +O 2  2H 2 O The product discharged is water &standard emf is 1.23volts. Applications: 1.These are used as auxillary energy source in space, vehicles, submarines & military vehicles. 2.The product in this cell is water &it is used as valuable fresh water &source for astronauts.

52. 52 Methanol-oxygen fuel cell: In this cell, CH 3 OH is used as a fuel & O 2 as a oxidant to generate electric current. This cell has two electrodes. porous nickel electrode coated with pt/pd catalyst act as anode & coated with silver catalyst act as cathode. The electrolyte KOH taken is in between two electrodes.

53. At anode :CH 3 OH + 6OH -  CO 2 +5H 2 O+6e - At cathode:3/2O 2 + 3H 2 O + 6e -  6OH - 53 Reactions: Net reaction:CH 3 OH +3/2O 2  CO 2 +2H 2 O Advantages : 1.These cells are reasonably stable at all environmental conditions. 2.Easy to transport. 3.Do not require complex steam reforming operations. 4.Methanol posses less risk to aquatic plants, animals & human beings than gasoline.

54. 54 1.The reactants and products are environment friendly. 2.High efficiency of energy conversion from chemical energy to electrical energy. 3.The fuels and electrolyte materials are available in plenty and inexhaustible unlike fossil fuel. 4.Fuel cells are operatable to 200 degree centigrade and so finds applications in high temperature systems. 5.Fuel energy is economical and safe. 6.Fuel cells are compact & transportabe . Advantages of fuel cells

55. Electrical Cheristics The ideal battery does not yet exist

56. Specific energy: Capacity a battery can hold ( Wh /kg) Specific power: Ability to deliver power (W/kg) Relationship between Power and Energy Power Energy

57. Non-rechargeable batteries hold more energy than rechargeables but cannot deliver high load currents Energy storage capacity

58. Ability to deliver current Kitchen clock runs on a few milliamps Power tool draws up to 50 amperes High power Low power

59. Lead Acid One of the oldest rechargeable batteries Rugged, forgiving if abused, safe, low price Usable over a large temperature range Has low specific energy Limited cycle life, does not like full discharges Must be stored with sufficient charge Produces gases, needs ventilation Vehicles, boats, UPS, golf cars, forklift, wheelchairs, Battery chemistries

60. Depth of discharge Starter battery Deep-cycle battery 100% 12 – 15 cycles 150 – 200 cycles 50% 100 – 120 cycles 400 – 500 cycles 30% 130 – 150 cycles 1,000 and more Types of Lead Acid Batteries Flooded (liquid electrolyte, needs water) Gel (electrolyte in gelled, maintenance free) AGM (absorbent glass mat, maintenance free) Lead acids come as starter, deep-cycle and stationary battery

61. Nickel-cadmium (NiCd) Rugged, durable, good cold temperature performance Cadmium is toxic, prompted regulatory restriction Aircraft main battery, UPS in cold environments, vessels, vehicles needing high cycle life, power tools (not in consumer products) Nickel-metal-hydride (NiMH) 40% higher specific energy than NiCd, mild toxicity Not as rugged as NiCd, more difficult to charge Consumer products, hybrid vehicles; being replaced with Li-ion Also available in AA and AAA cells Officials mandated a switch from NiCd to NiMH. NiMH has same voltage, similar charging characteristics to NiCd.

62. There are two types of Lithium Batteries Non-rechargeable - Heart pace makers - Defense - Instrumentation - Oil drilling Rechargeable - Mobile phones - Laptops - Power tools - Electric powertrains Lithium ion (intercalated lithium compound) Lithium (metallic)

63. Li-ion Systems Li-cobalt (LiCoO2) Available since 1991, replaces NiCd and NiMH. Lighter, longer runtimes. NMC (nickel-manganese-cobalt) High specific energy. Power tools, medical instruments, e-bikes, EVs. Li-phosphate (LiFePO4) Long cycle life, enhanced safety but has lower specific energy. UPS, EVs

64. Lithium-polymer Hype Lithium-polymer (1970s) uses a solid electrolyte. Requires 50–60  C operating temperature to attain conductivity. Modern Li-polymer includes gelled electrolyte; can be built on Li-cobalt, NMC, Li-phosphate and Li-manganese platforms. Li-polymer is not a unique chemistry but a different architecture. Characteristics are the same as other Li-ion chemistries. Polymer serves as marketing catchword in consumer products

65. Lead acid: 2V/cell nominal (OCV is 2.10V/cell) NiCd, NiMH: 1.20V/cell (official rating is 1.25V/cell) Li-ion: 3.60V/cell (Some are 3.70V, 3.80V*) * Cathode material affect OCV. Manganese raises voltage. Higher voltage is used for marketing reasons. Confusion with Nominal Voltages Official Li-ion Ratings Li-ion 3.60V/cell Li-phosphate 3.30V/cell

66. Microscopic metal particles can puncture the separator, leading to an electrical short circuit. (Quote by Sony, 2006) Modern cells with ultra-thin separators are more susceptible to impurities than the older designs with lower Ah ratings. External protection circuits cannot stop a thermal runaway. In case of overheating battery Move device to non-combustible surface. Cool surrounding area with water Use chemicals to douse fire, or allow battery to burn out. Ventilate room. Safety concerns with Li-ion

67. 2. Packaging and Configurations In ca. 1917, the National Institute of Standards and Technology established the alphabet nomenclature.

68. The inherent instability of lithium metal, especially during charging, shifted research to a non-metallic solution using lithium ions . Battery formats Type Size (mm) History F 33x90 1896 for lantern, later for radios , NiCd only E N/A 1905 for lantern and hobby, discontinued 1980 D 34x61 1898 for flashlight, later radios C 25.5x50 1900 as above for smaller form factor B N/A 1900 for portable lighting, discontinued 2001 A 17x50 NiCd only, also in half-sizes AA 14.5x50 1907 for WWI; made standard in 1947 AAA 10.5x44.5 1954 for Kodak, Polaroid to reduce size AAAA 8.3x42.5 1990 for laser pointers, flashlights, PC stylus 4.5V 85x61x17.5 Flat pack for flashlight, common in Europe 9V 48.5x26.5x17.5 1956 for transistor radios 18650 18x65 Early 1990s for Li-ion 26650 26x65 Larger size for Li-ion

69. Classic packaging for primary & secondary cells High mechanical stability, economical, long life Holds internal pressure without deforming case Inefficient use of space Metal housing adds to weight Cylindrical cell

70. Button cell Also known as coin cells; small size, easy to stack Mainly reserved as primary batteries in watches, gauges Rechargeable button cells do not allow fast charging Limited new developments Must be kept away from children, harmful if swallowed (voltage)

71. Prismatic cell Best usage of space Allows flexible design Higher manufacturing cost Less efficient thermal management Shorter life

72. Pouch cell Light and cost-effective to manufacture Simple, flexible and lightweight solutions Exposure to humidity, hot temperature shorten life Loss of stack pressure; swelling due to gassing Design must include allowance for 8-10% swelling Some cells may bloat

73. Best Cell Design Cylindrical cell has good cycling ability, long life, economical to manufacture. No expansions during charge and discharge. Heavy; creates air gaps on multi-cell packs. Not suitable for slim designs. Less efficient in thermal management; possible shorter cycle life; can be more expensive to make. Exposure to humidity and heat shorten service life; 8–10% swelling over 500 cycles. Pouch pack is light and cost-effective to manufacture. Prismatic cell allows compact design; mostly used for single-cell packs.

74. Serial connection Adding cells in a string increases voltage; same current Faulty cell lowers overall voltage, causing early cut-off Weakest cell is stressed most; stack deteriorates quickly Good string Faulty string

75. Parallel connection Good parallel pack Faulty parallel pack Allows high current; same voltage Weak cell reduces current, poses a hazard if shorted

76. Serial-parallel connection Most battery packs have serial-parallel configurations Cells must be matched 2S2P means: 2 cells in series 2 cells in parallel

77. 3. Charging, Discharging, Storing A battery behaves like humans; it likes moderate temperatures and light duty.

78. Charges in ~8h. Topping charge a must Current tapers off when reaching voltage limit Voltage must drop when ready on float charge The right way to charge lead acid Charge to 2.40V/cell, then apply topping charge 2.25V/cell float charge compensates for self-discharge Over-charging causes corrosion, short life

79. The right way to charge NiMH NiCd & NiMH charge in 1-3 hours; floating voltage Voltage signature determines full charge Trickle charge on NiMH limited to 0.05C; NiCd less critical Charge to 70% efficient, then battery gets warm Full-charge detection difficult if battery faulty, mismatched Redundant full charge detection required Temperature sensing is required for safety

80. The right way to charge Li-ion Li-ion charges in 1-3 hours (2/3 of time is for topping charge) Full charge occurs when current drops to a set level No trickle charge! (Li-ion cannot absorb overcharge) Charge to 4.20V/cell Absolutely no trickle charge; cells must relax after charge Occasional topping charge allowed

81. What batteries like and dislike Lead acid needs an occasional 14h saturation charge. Lead acid cannot be fast-charged. (A fast charge is 8h). Charging/discharging faster than 1h (1C-rate) causes stress. Charging and discharging Li-ion above 1C reduces service life

82. Charging / Discharging Chargers must safely charge even a faulty battery Chargers fill a battery, then halt the charge Overcharge hints to a faulty charger Discharge must be directed to a proper load Analogy Water-flow stops when the tank is full. A faulty mechanism can cause flooding. Placing a brick in the tank reduces capacity.

83. Some batteries can be charged in less than 30 minutes, but Ultra-fast charging only works with a perfect pack Fast-charging causes undue stress, shortens life For best results, charge at 0.5 – 1C-rate (1 – 2h rate) As a high-speed train can only go as fast as the tracks allow. Likewise, a battery must be in good condition to accept fast charge. Ultra-fast charging Use moderate charge if possible Chinese high-speed train

84. Charging without wires Inductive charging resembles a transmitter and receiver Received magnetic signals are rectified and regulated Transmitter and receiver command power needs Inductive charging is 70% efficient; produces heat

85. Advantages Convenience, no contact wear Helps in cleaning, sterilization No exposed metals, no corrosion No shock and spark hazard Power limit prolongs charge times Generated heat stresses battery Concerns regarding radiation Complex, 25% more expensive Incompatible standards (Qi, PMA, A4WP) Disadvantages

86. Battery Type Charge Temperature Discharge Temperature Charge Advisory Lead acid –20  C to 50  C (–4  F to 122  F) –20  C to 50  C (–4  F to 122  F) Charge at 0.3C, less below freezing. Lower V-limit by 3mV/  C >30  C NiCd, NiMH  C to 45  C (32  F to 113  F) –20  C to 65  C (–4  F to 149  F) Charge at 0.1C between –18 and 0  C Charge at 0.3C between 0  C and 5  C Li-ion  C to 45  C (32  F to 113  F) –20  C to 60  C (–4  F to 140  F) No charge below freezing. Good charge/discharge performance at higher temperature but shorter life Charging at high and low temperatures UCC charger by Cadex observes temperature levels while charging Important: Charging has a reduced temperature range than discharging.

87. Charging from a USB Port The Universal Serial Bus (USB) introduced in 1996 is a bi-directional data port that also provides 5V at 500mA Charges small single-cell Li-ion Full charge may not be possible on larger packs Overloading may cause host (laptop) to disconnect Type A USB plug Pin 1 provides +5VDC Pins 2 & 3 carry data Pin 4 is ground. 4 1

88. Discharge methods Higher loads and pulses increase stress on a battery Weak cells in a chain suffer most on load, fast charge Cells must be matched for high current discharge Source: Choi et al (2002)

89. Storing Lead acid: Fully charge before storing - Partial charge causes sulfation - Self-discharge increases with heat - Topping-charge every 6 months NiCd, NiMH: No preparation needed - Can be stored charged or empty - Needs exercise after long storage Li-ion : Store at 30-60% SoC - Charge empty Li-ion to 3.85V/cell - Discharge full Li-ion to 3.75V/cell (3.80V/cell relates to ~50% SoC) Do not purchase batteries for long storage. Like milk, batteries spoil.

90. Health concerns with lead Lead can enter the body by inhalation of lead dust or touching the mouth with contaminated hands. Children and pregnant women are most vulnerable to lead exposure. Lead affects a child’s growth, causes brain damage, harms kidneys, impairs hearing and induces behavioral problems. Lead can cause memory loss, impair concentration and harm the reproductive system. Lead causes high blood pressure, nerve disorders, muscle and joint pain.

91. Health concerns with cadmium Workers at a NiCd manufacturing plant in Japan exhibited heath problems from cadmium exposure Governments banned the disposal of nickel-cadmium batteries in landfills Cadmium can be absorbed through the skin by touching a spilled battery; causes kidney damage. Exercise caution when working with damaged batteries

92. Transporting Li-ion Estimated Li-ion failure is 1 per 10 million pack (1 in 200,000 failure triggered a 6 million recall in 2006) Most failures occur by improper packaging and handling at airports and in cargo hubs. Li-ion is not the only problem battery. Primary lithium, lead, nickel and alkaline can also cause fires. Battery failures have gone down since 2006.

93. Maximum lithium or equivalent lithium content (ELC) shipped under Section II 2g lithium in a lithium-metal battery (primary) 8g ELC in a single Li-ion pack (up to 100Wh) 25g ELC if in several packs (up to 300Wh) To calculate ELC, multiply Ah times 0.3. Spare batteries must be carried, not checked in. Shipment exceeding Section II by land, sea and air must be expedited under “Class 9 miscellaneous hazardous material.”

94. FAQ Lead acid Nickel-based Li-ion Can I harm battery by incorrect use? Yes, do not store partially charged Do not overheat, do not overcharge Keep cool, store ate partial charge Is a partial charge fine? Charge fully to prevent sulfation Charge NiCd and NiMH fully Partial charge fine Do I need to use up all charge before charging? No, deep dis-charge harms the battery Apply scheduled discharges only to prevent “memory” Partial discharge is better, charge more often instead Will the battery get warm on charge? Slight temperature raise is normal Gets warm; must stay cool on ready Must always remain cool Can I charge when cold? Slow charge only (0.1) at 0–45°C Fast charge (0.5–1C) at 5–45°C Do not charge below °C Can I charge at hot temperature? Lower V threshold when above 25 °C Will not fully charge when hot Do not charge above 50 °C How should I store my battery? Keep voltage above 2.05V/cell Can be stored totally discharged Store cool and at a partial charge FAQ on charging and discharging

95. 4. How to prolong Battery Life Batteries are sometimes replaced too soon, but mostly too late.

96. Li-ion provides 300-500 full discharge cycles Capacity is the leading health indicator of a battery A capacity-drop to 80 or 70% marks end of life Capacity loss of 11 Li-ion batteries for mobile phones when fully cycled at 1C Battery fade cannot be stopped, but slowed

97. SoC includes Stored Energy and Inactive part Knowing the difference between Capacity and SoC Capacity and SoC determine the runtime but the siblings are not related Rated Capacity (Ah) includes the Empty, Stored Energy and Inactive part Available Capacity represents the actual playfield

98. Avoid deep discharges Cycle life as a function of depth-of-discharge ( DoD ) Depth of discharge Number of discharge cycles of Li-ion, NiMH 100% DoD 300 - 500 50% DoD 1,200 - 1,500 25% DoD 2,000 - 2,400 10% DoD 3,750 - 4,700 Prevent deep discharges; charge more often Only apply a deliberate full discharge for calibration NiCd & NiMH benefit from periodic cycling (memory) Satellites

99. Keep battery cool Function of SoC and temperature Capacity of Li-ion after 1 year Temperature 40% charge 100% charge 0°C 98% 94% 25 °C 96% 80% 40 °C 85% 65% 60 °C 75% 60% ( after 3 months ) Heat in combination of full-charge hastens aging Laptop

100. Retain moderate charge voltage Longevity as a function of charge voltage Charge level V/cell of Li-ion Number of full discharge cycles Capacity at full charge (4.30) (150 – 250) (110%) 4.20 300 – 500 100% 4.10 600 – 1,000 90% 4.00 1,200 – 2,000 70% 3.90 2,400 – 4,000 50% Every 0.10V below 4.20V/cell doubles cycle life; lower charge voltages reduce capacity

101. Table of Battery Dos and Don’ts Battery care Lead acid Nickel-based Li-ion Best way to charge Apply occasional full 14h charge to prevent sulfation; charge every 6 month Avoid leaving battery in charger on Ready for days (memory). Partial charge fine; lower cell voltages preferred; keep cool. Discharge Do not cycle starter batteries; avoid full discharges; always charge after use. Do not over-discharge at high load; cell reversal causes short. Keep protection circuit alive by applying some charge after a full discharge. Disposal d o not dispose; recycle instead. Lead is a toxic. Do not dispose NiCd. NiMH can be disposed at low volume. Environmentally friendly. Can be disposed at low volume.

102. 5. Summary The battery is energy storage device that is slow to fill, holds limited capacity and has a defined life span.

103. Lead acid is making a come-back Li-ion replaces Nickel-based batteries Li-ion for UPS costs 5-time more than lead acid Capacity in Li-ion doubled since the 1991 introduction How far batteries can go is checked in electric vehicles As long as the battery relies on an electrochemical process, limitations prevail. The ideal battery does not yet exist. Lemon battery What people say . . .

104. Batteries do not die suddenly but gradually fade with age. Capacity is the leading health indicator. Battery diagnostics has not advanced as quickly as other technologies. The challenge is in assessing a battery before performance degradation becomes noticeable. Rapid-test provide 80–90% correct prediction. Capacity measurement by a full discharge is still the most reliable method. Limitations with Current Technologies Batteries must be treated like any other part of a medical device

105. EV sets the upper boundary on battery feasibility. Price and longevity dictate how far the battery can go. Powering trains, ships and airplanes makes little sense. Competing against oil with a 100x higher net calorific value that is tough to meet, but . . . Petroleum cannot touch the battery that is clean, quiet, small, and provides an immediate start-up . How far can the Battery go?

106. Net Calorific Values Fuel Energy by mass ( Wh /kg) Diesel 12,700 Gasoline 12,200 Body fat 10,500 Ethanol 7,800 Black coal (solid) 6,600 Wood (average) 2,300 Li-ion battery 150 Flywheel 120 NiMH battery 90 Lead acid battery 40 Compressed air 34 Supercapacitor 5 Complied from various sources. Values are approximate