2. Content of the Syllabus
• Types and Packs with respect to
Construction
Working
Comparison
Selection (lead-acid, nickel based, lithium-based batteries)
• Noise Factors
• Battery Packs design against Noise and Vibration exposure
• Vibration exposure (Mode shapes)
• Vehicle Dynamics
• Battery Pack
• Cooling System and Thermal Management.
3. Introduction:
• “Energy storages” are defined as the devices that store energy, deliver energy outside
(discharge), and accept energy from outside (charge).
• There are several types of energy storages that have been proposed for electric vehicle (EV)
and hybrid electric vehicle (HEV) applications. These energy storages, so far, mainly include
chemical batteries, ultracapacitors or supercapacitors, and ultrahigh-speed flywheels and the
fuel cell.
• There are a number of requirements for energy storage applied in an automotive application,
such as specific energy, specific power, efficiency, maintenance requirement, management,
cost, environmental adaptation and friendliness, and safety.
• For allocation on an EV, specific energy is the first consideration since it limits the vehicle
range. On the other hand, for HEV applications, specific energy becomes less important and
specific power is the first consideration, because all the energy is from the energy source
(engine or fuel cell) and sufficient power is needed to ensure vehicle performance,
particularly during acceleration, hill climbing, and regenerative braking. Of course, other
requirements should be fully considered in vehicle drive train development.
9. Energy Storage System Components
• The battery system consists of the battery pack, which connects multiple cells to appropriate voltage
and capacity; the battery management system (BMS); and the battery thermal management system
(B-TMS). The BMS protects the cells from harmful operation, in terms of voltage, temperature, and
current, to achieve reliable and safe operation, and balances varying cell states-of-charge (SOCs)
within a serial connection. The B-TMS controls the temperature of the cells according to their
specifications in terms of absolute values and temperature gradients within the pack.
• The components required for the reliable operation of the overall system are system control and
monitoring, the energy management system (EMS), and system thermal management. System control
and monitoring is general (IT) monitoring, which is partly combined into the overall supervisory
control and data acquisition (SCADA) system but may also include fire protection or alarm units. The
EMS is responsible for system power flow control, management, and distribution. System thermal
management controls all functions related to the heating, ventilation, and air-conditioning of the
containment system.
• The power electronics can be grouped into the conversion unit, which converts the power flow
between the grid and the battery, and the required control and monitoring components voltage sensing
units and thermal management of power electronics components (fan cooling).
12. Container of LeadAcid Battery
• This jar component is made of ebonite, lead-coated wood, glass, bituminous hard rubber,
ceramic materials, or forged plastic, both of which are mounted on the surface to prevent
any electrolyte discharge. In the bottom portion of the container, there are four ribs, two of
which are mounted on the positive plate and the others on the negative plate.
• The prism serves as a foundation for both plates while also protecting them from short-
circuiting. The materials used in the container's construction should not contain sulphuric
acid, should not bend or permeate, and should not carry any impurities that could cause
electrolyte harm.
Active Component of LeadAcid Battery
• An active component is one that actively participates in the chemical reaction processes
that occur in the battery, mostly during charging and discharging. The following are the
active ingredients:
• Peroxide of lead & ndash; It is a beneficial active ingredient.
• Sponge lead is the negative active portion of the system.
• Sulphuric acid, diluted – This is mostly used as an electrolyte.
13. Plates of Lead Acid Battery
• The plates in a lead acid battery are built in a variety of ways, but they are all made up of the
same types of grid, which is made up of active components and lead. The grid is essential for
establishing current conductivity and distributing equal quantities of current to the active
components. There would be loosening of the active variable if the distribution is unequal.
There are two types of plates in this battery. Plante/formed plates and Faure/pasted plates are
the two types.
• The shaped plates are mostly used in static batteries, and they are both heavy and costly.
However, even in continual charging and discharging cycles, they have a long lifespan and are
unlikely to lose their active components. This has a low capacity-to-weight ratio.
• Although the pasted procedure is more commonly used to create negative plates than positive
plates, it is often used to create positive plates. The negative active aspect is more complex,
and the charging and discharging mechanisms are slightly altered.
Separators of LeadAcid Battery
• Porous rubber, treated leadwood, and glass fiber are used to make these thin boards. The
separators are used to provide active insulation between the plates. In one rim, they have a
grooved form, while the other sides are flat.
• Battery Edges of LeadAcid Battery
• It has 17.5 mm and 16 mm diameter positive and negative tips, respectively.
14. • These batteries mostly comprise Electrodes, Lead plates, and an electrolyte which are the basic
composition of a Lead-acid battery.
• Between the positive and negative electrodes, there are separators that allow ions to flow and
hence complete the circuit of battery composition.
• In AGM type, the separators in replaced with glass fiber mat soaked in electrolyte. This increases
the exchange or passing of gasses produced during the charging and discharging process.
• For this purpose, the electrolyte in AGM is replaced from liquid to semi saturated type. While
electrolyte in the most basic construction of the lead-acid battery is a mixture of sulfuric acid and
water(Distilled).
• In VRLA batteries, which are basically sealed batteries, vents are provided for the release of gases
produced inside the battery.
• These (VRLA) batteries are also called gel batteries, we have seen these most commonly in
household devices like insect rackets.
• Due to the gel-type electrolyte, the advantages of AGM and VRLA are the same. These all make
them mostly used batteries in extreme conditions, as they have low freezing and high boiling
points than basic (wet) orAGM types.
• These all advantages of the AGM and VRLA make them maintenance-free as they do not require
watering and gas valve for gas blow off.
15. • There are many uses of the lead-acid battery,
These are used from small devices like an
insect racket to big and heavy machinery like a
forklift.
• All types of automobiles use the lead-acid
battery either SLA or VRLA for ignition of
engine and electric uses. Also, these batteries
need to be recharged with both CC & CV
techniques for a better life cycle.
• Most of the electric toys used lead-acid
batteries also in the robotics field we use the
lead-acid battery for most of the low-cost
projects.
• These are also used in heavy machinery like
Forklift in factories and industries which
require drawing a large amount of current in a
very short time.
16. Advantages of lead acid battery:
• The main and most important advantage of the lead-acid battery is the cost over the other types of batteries.
If we calculate the price of a lead-acid battery in terms of watt/per hour, is rather very cheap and cost-effective
in all types of batteries.
• Secondly, the construction and packaging of the lead-acid battery are tough & rigid which overall all increases
its durability over other batteries
• Also, these batteries can be recharged, and mostly the type of which is used in homes or UPS can easily be used
as they require only water refilling as maintenance.
• Further, these batteries have the capability of delivering large current to load and appliances, hence these are
more popular among high power devices and tools.
• Also, if the battery is overcharged or discharged the gasses can easily escape either through the gas valve or the
water opening timely despite other batteries which leak or get puffed up.
Disadvantages:
• Most importantly, these batteries type has the lowest energy density which makes them non-ideal for portable
and mobile devices or in simple words handy devices.
• The electrolyte is dangerous and quite risky while transporting these batteries, a these may leak or spill in
between.
• Another disadvantage of these types is that you cannot use them just after the charging or just after water
refilling charging as you need to wait for 12-14 hrs for voltage stabilization.
• Although they are the most recyclable battery type, the material used in these LEAD(Pb) is toxic which can
cause harm if improperly recycle.
17. Ni-Cd Batteries:
• These batteries are similar to other cell or cylindrical type batteries, but the construction and effects are different
from others.
• Unlike Lead-Acid batteries, they come in a cylindrical package and a nominal voltage of around 1.2V to 1.4V.
These need to be connected in series and parallel for making the appropriate battery pack for the power supply.
• But they also have some characteristics similar to Lead-Acid battery, like they can deliver high current at their
full capacity. This even doesn’t affect their life and performance cycle.
• Along with this they can adapt to fast and easy charging even if you charge them after a long time. But in the
recommendation, they must be taken into use in tasks that require periodic usage, or due to their self-power loss,
they may discharge overtime and get damaged.
18. • The construction of these batteries is rather quite compact as compared to a lead-acid battery. They
come in two types or sizes which are mostly used, AA size and D size, but the construction for both is
the same.
• The batteries are enclosed, or they have metal packaging with a self-sealing plate, including a self-
sealing safety valve at the positive terminal.
• The positive and negative terminal electrodes are separated from each other by a separator, but both
electrodes are rolled in the form of a spiral in the metal casing.
• The electrolyte is of some alkali solution, which separates both positive and negative electrode.
• The positive electrode is made up of NiO(OH) and the negative electrode is of Cd. These both are
rolled up as stated above with electrolyte in between them as medium for passing the ions, with the
separator sandwiched between both the electrode layers.
Applications of nickel cadmium battery :
• The main or most common application of the Ni-Cd battery is forming battery packs of the desired
value by arranging them into series and parallel.
• Single cells are used in toys and household devices like RC toys and electric trimmers.
• The smaller button cell construction of these types of batteries is also used in handheld devices or in
BIOS memory backup batteries in computers.
• vehicles as battery packs nowadays as these can provide large current as a lead-acid batteries without
affecting their capacity or battery life.
19. Advantages:
• First of all they can adapt to fast, quick and easy charging with any balanced charger available or them.
Also, theses doesn’t affect their life cycle or capacity, even using after along period of time.
• Secondly, they have high energy density as compared to Lead acid battery. The AA and D Size battery
packages can offer a same amount of power as a Lead-Acid battery, but in a smaller package or space.
• Even though the material used in the construction is not as durable and strong as Lead-Acid battery, yet
they are quite durable and robust.
• They are also recyclable through thermal treatment under vacuum to recollect the Cd. Ni is also recycled
in the form of Ni-Fe alloy.
• If the battery is overcharged then the excess water above the limit of safety valve, which is formed during
the process, it released in vapour state.
Disadvantages:
• The most important and harmful disadvantage of these batteries is that they are formed or the composition
of the electrodes is of toxic materials. Which is discharged in the environment during the recycle or and
other ways can be harmful to the environment.
• Secondly, if the battery is overcharged then the excess water will be released from the safety valve, but it
will affect its capacity.
• This type of battery is also prone to memory effect, which is caused by the same charging and discharging
cycles of the battery regularly.
• These batteries also self discharge at a rate of 20% per month under identical conditions.
20. Ni-MH Battery
• Ni-MH which stands for Nickel-Metal Hydride Batteries.
• These batteries are more popular than Ni-Cd due to 3-4 times more capacity, which overall increases
their energy density of them.
• The sixes and packages of the Ni-MH batteries are similar to the Ni-Cd batteries, but the current
rating is much more than Ni-Cd batteries
• These are identical to alkaline batteries and even can be used as their replacement, the only issue is of
the slightly less voltage.
• the full name of NI-MH battery is nickel metal hydrite battery.
• The construction of the Ni-MH batteries are similar to the Ni-Cd batteries, but they are both different
in the material and separators used.
• The positive electrode is made of the same material as Ni-Cd, or NiO(OH), while the negative
electrode is made of the Hydrogen absorbing alloy instead of Cadmium.
• The electrolyte, in this case, is Potassium Hydroxide (KOH) which is also filled in between both
electrodes which are rolled up in the form of a spiral as a Ni-Cd battery separated by a separator.
• These are also capable of delivering high current as similar to Ni-Cd, which is an advantage of them
over alkaline batteries in single charge use.
• Furthermore, these also have the self-sealing safety valve for the release of gasses during the
overcharge process, like in case of Ni-Cd batteries construction.
22. Applications of NI-MH battery :
• It’s most of the applications are similar to the Ni-Cd batteries. Due to its more popular AA and D-size and large
current rating, it is commonly found in various battery packs.
• In RC Toys and consumer electronics used in a house, also in power tools like electric drills and cutter due to
their large current supplying capability.
• It is also used in Vehicles as battery packs instead of Lead-Acid batteries or in electric vehicles as an alternative
to Li-Ion batteries which are used conventionally.
• Despite these, it is also used in older laptops in place of Li-Ion and in cell phone as a portable power source with
higher power capacity.
23. Advantages:
• The main advantage of these batteries is the more capacity than the Ni-Cd batteries, which is great in terms of energy density.
• The material used in manufacturing the batteries is not as toxic as Ni-Cd, so it is more environmentally friendly than Ni-Cd
ones.
• There are many ways of charging these batteries like either monitoring changing voltage or temperature, or you can also use
trickle charging method.
• In changing voltage or temperature techniques the voltage or temperature changes are being monitored over time and according
to the datasheet of the battery the current of C value is set.
• In the trickle charging method, the battery is charged constantly at 0.1C current. But this method is for a long time and if
overcharged can reduce battery life.
• For safety features, it has a bimetallic resettable fuse that opens if either the current or the temperature is too high and closes
again when it is under a suitable range.
• They also have a relatively low self-discharge rate, which is also an advantage of using them over Ni-Cd batteries.
Disadvantages:
• The main disadvantage of these batteries is that they have a low life cycle, also after a few hundred charges you can witness
the drop in their capacity.
• if you over-discharge these batteries then these may also show reverse polarity which can permanently damage the batteries.
• Also, it is advised either to use appropriate power battery packs for power tools or if you used underrated power battery
packs then the life cycle of individuals may shorten.
• Due to it having high energy density than Ni-Cd ones, these also have a high cost than those, which can be a bit costly for
large scale.
• It is recommended to use desired battery balanced charges for charging the batteries, or it may damage the batteries
permanently due to more complex algorithm charging than Ni-Cd.
24. Li-Po Battery
• This is one of the most famous, mostly used batteries in projects. Due to its high capacity and wide range of
sizes and availability.
• Li-Po or Lithium-ion Polymer battery is another type of battery with polymer electrolyte instead of conventional
Liquid or semi-liquid electrode.
• These batteries work on the principal of intercalation and de-intercalation between positive and negative lithium
electrodes.
• These batteries are rather very cheap as compared to the Ni-Cd and Ni-MH cells also they come in thin to thick
sizes which make them ideal for using in small spaces.
• The construction of the Li-Po is not spiral as in the case of Ni-Cd and Ni-MH, but both electrodes are
individually wrapped but both the electrodes are of lithium only.
• For separating both the electrodes, a separator of material like polythene or polypropylene is used, which is
microporous and allows the ions to exchange.
• The positive electrode is usually a mixture of 3 parts that are lithium with transition metal oxide, a conductive
additive, and a poly binder.
• The negative electrode is similar to the positive electrode i.e., the mixture of 3 parts the only difference is that
there is a mixture of carbon with lithium.
• The electrolyte is a polymer as stated above instead of conventional liquid or semi-liquid electrolyte, but this
doesn’t affect the capacity or life.
• The outer covering or the pouch in which the battery is packed is la layer of aluminium foil sandwiched
between two polymers.
25. Applications of lipo battery:
• These batteries have very high and most demanding usages. Due to their various size and
capacity options, they are 1st choice for any project.
• They are used in most RC flying toys, as they require lightweight and high-capacity batteries
with high current ratings.
• Nowadays, these batteries are also used in various household and handheld devices due to their
compactness and less spacing-taking capabilities.
• Also used in electric vehicles as a replacement of the Li-Ion, Ni-Cd & Ni-MH cells as these are
quite costly and require a decent and fixed amount of space per cell.
• Moreover also used in UPS and jump starters as a combination of cells, as the combination can
supply large current in emergency situations.
Advantages:
• The main advantage of these batteries is the shape and sizes of the batter and the high energy as
compared to Ni-Cd and Ni-MH batteries if compared on the same weight and volume bases.
• The wide range of choices and C rating along with S&P battery packs are a big advantage over
other battery types.
• Along with these, batteries have low internal resistance which allows them to deliver high current
during required times such as RC toys.
26. • They have higher energy density than that of Ni-Cd and Ni-MH batteries, which are costly. These
batteries can over more amount of power at the same cost as that of a cell of Ni-Cd or Ni-MH ones.
• The terminals of these batteries are easily soldered unlike cell packaging of any other battery as those
require either a Spot Welder or some sandpaper rubbing and then soldering.
Disadvantages:
• The main disadvantage of these batteries is that they puffed up are kept full charge or sometimes also
leak, leaving a foul smell around them.
• These batteries need s to be charged at CC/CV methods or the cell may damage over time or lose its
capacity.
• Also, if you short circuit the battery by chance, the battery may cause fire and or may explode in
certain situations.
• If these batteries are used at low temperature like below 10 °C then you’ll see a degradation in their
performance and capacity, same as for high temperature like above 50 °C these batteries have a high
chance of exploding.
• The terminals, if soldered without any heat sink or use of thick wires the point or terminals may tear
off, and you may damage your battery.
• High capacity battery needs constant a CC/CV charger and a battery monitor with corresponded to
each cell especially for drones and RC planes.
27. Li- ion battery:
• The shape and sizes of these batteries are usually AA or AAA sizes, but also they are custom-made in various sizes
on demand, like as found in mobile phones.
• These batteries have the highest energy density among all batteries and are relatively costlier than any other type,
but like coin has two sides, these have advantages also.
• The nominal or normal voltage of any battery size of Li-Ion battery is 3.7V and if you charge the battery you need
to follow the CC/CV methods for each cell to ensure their battery life.
• The construction of a lithium-ion battery consists of numerous individual cells, each with the same structure. It
contains the following components:
• Positive electrode: The cathode consists of lithium metal oxide, which may contain variable amounts of nickel,
manganese and cobalt. These metal oxides are also called transition metals.
• Negative electrode: The anode is usually made of graphite.
• Electrolyte: In order for the lithium ions to move as charge carriers in the cell, anhydrous electrolytes are also
included. These contain salts such as lithium hexafluorophosphate dissolved in an aprotic solvent such as diethyl
carbonate. In lithium polymer batteries, a polymer of polyvinylidene fluoride or polyvinylidene fluoride-
hexafluoropropylene is also used at this point.
• Separator: To prevent short circuits, a separator made of nonwovens or polymer-films is installed between the
electrodes. The separator is permeable to lithium ions and can absorb large quantities.
• The design allows lithium to move back and forth between the electrodes in ionized form. Depending on the
electrode materials used, lithium-ion batteries are divided into different groups. Operation remains the same in
each, but the energy density, cell voltage, temperature sensitivity, capacity, and charge capacity and discharge
current can vary with different transition metal ions.
30. Li- ion battery (lipo battery Construction):
• As these batteries are commonly found in either AA or AAA size, the construction of bases on these two.
Also, in some places, we’ll give references for other sizes.
• The positive electrode of these batteries is mostly made of Metal Oxide, which can be of one of these 3
materials. A layered oxide such as lithium cobalt oxide, polyanion such as Lithium Iron Phosphate, or a
spinel such as lithium manganese oxide.
• The negative electrode is made of carbon, mostly graphite, which in its fully lithiated state of LiC6 has a
capacity of about 372mAh/g.
• The electrolyte in these batteries is a lithium salt in an organic solvent, as for the separator between the
electrodes it is basically polyethylene or polypropylene.
• The basic outer covering that is found in cells is of metals case without bulged surface as in normal batteries,
whereas large cells have threaded terminals for screwing the wires and connectors.
Applications of lipo battery:
• These are mostly used and very popular battery, and it has numerous application and uses. The highest
energy density and cost-to-energy ratio make them ideal for usage.
• The most common use which everyone has is the mobile phones. Modern smartphones require a large power
capacity battery but less weight, a Li-Ion battery is ideal for these.
• Secondly, modern laptops like MacBooks and book-type laptops and tabs are also the major field of
application of these batteries.
• Power tools and Hand-held devices which are used in houses are also very common uses of Li-Ion batteries,
• Wireless devices and automobiles are also a growing field of usage of the Li-Ion batteries. The cell, of AA
andAAAsizes, are most common.
31. The structure of a lithium-ion battery can be manufactured as:
• Lithium-polymer batteries: The electrolyte used is a polymer-based film with a gel-like
consistency. This structure makes it possible to manufacture particularly small batteries
(less than 0.1 mm thick) and in various designs. With an energy density of up to 180
Wh/kg, they are very powerful, but mechanically, electrically and thermally sensitive.
• Lithium cobalt dioxide batteries: The positive electrode of this type of battery is made of
lithium cobalt dioxide. The anode is made of graphite. These types of batteries are prone to
thermal runaway when overloaded.
• Lithium titanate batteries: Negative electrodes are not made of graphite, but of sintered
lithium titan spinel. These enable a superfast-charging capacity as well as operation
at temperatures as low as -40°C. The positive electrodes are again made of lithium
titanium oxide.
• Lithium iron phosphate batteries: Cells each have a cathode made of lithium iron
phosphate. The electrolyte is present in solid form. These batteries have a lower
energy density of up to 110 Wh/kg, but are not prone to thermal runaway if mechanically
damaged. The discharge voltage curve indicates a memory effect, but this is very low
compared to Ni-Cd alternatives.
32. Advantages:
• The first advantage which makes it ideal is its high energy density, which outperforms every battery type in many
comparisons.
• Secondly, the various sizes and low cost of producing the custom size battery make it easy to afford batteries for low budgets
projects.
• They can be easily recycled also can be reused more easily than any other batteries like Lead-Acid and Ni-Cd or Ni-MH,
which are either harmful to the environment or hard to recycle.
• They have a very low self-discharge rate, like 2% to 3% per month of the original C rating of the battery. Also, the adequate
rate of temperature range makes them able to use in almost all conditions (5 °C to 45 °C).
• Though the charging methods are the same as CC/CV, the charges are easy to afford same in the case of Li-Po battery but
these both need different charges as per their type.
• This battery is almost free from memory effect, which is the most important issue in cases of Drones and RC toys and
devices.
Disadvantages:
• The main disadvantage of these batteries is they need care and monitoring while charging as higher temperature during
charging may lead to leaking or even burning of battery causing a fire.
• The terminal of these batteries in AA or AAA size batteries needs to be either spot welded or first rubbed with sandpaper and
then soldered as same in the case of Li-Po batteries.
• You cannot keep the battery in the charged state as it will make the battery puffed up and lead to the destruction of the battery.
Even troubleshooting methods on YouTube didn’t work as it ultimately result in the loss of the capacity of the battery.
• They are not as good as Ni-Cd or Ni-MH in power tools which are portable as discharging current is less than compared to
other both types.
• You cannot fold or put excessive pressure on rectangular type packages as it may result in a leak or immediate fire, same as
for Li-Po batteries.
33. Li- ion battery pack:
• The diagram below illustrates the typical elements found in a rechargeable battery pack:
• Cells (Different form factors & chemistry types)
• BMS (Electronics to manage the battery)
• Connection System (Connector, pigtail, wires)
• Housing (Plastic, sheet metal, shrink, etc.)
34. • At the base of every Li-ion battery pack is the battery cell or cells. A pack can contain one
cell or many cells configured to achieve higher capacity or output voltage. This is achieved
by connecting cells in parallel or series, and we'll explore this much further in our next
blog. The cell is considered the “fuel tank” of the battery pack system, holding the energy
that will be released during discharge (when the engine is running) or replaced during a
charge cycle (when the tank is refilled at a gas station). However, there are other
components needed to utilize the energy stored in the cell.
• To safely use the energy stored in cells, the Li-ion battery pack needs a Battery
Management System (BMS). The BMS is the control system of the pack and can be
simple or complex, depending on the need of the battery pack and host application.
Returning to the car analogy, think of a battery pack's BMS like a car's control system. In a
car, the control system shuttles fuel from the fuel tank to the engine to be utilized in a
controlled and safe manner and notifies the user of any issues (i.e. low fuel). The BMS
performs a similar role by safely regulating the energy carried through the cells inside a
battery pack. It can also communicate information back to the end user (i.e. low battery
life).
35. • The connection system is what transforms a cell into a battery pack. Nickel strips are the
preferred method of connecting a battery cell to the control system. A thin strip of nickel is
capable of carrying high amounts of current, is flexible, durable, and can be attached to the
cell without the use of excessive heat. These strips provide a safe means of getting the
"fuel" out of the "fuel tank" to use it in a safe manner.
• Finally, all these components need to be packaged so that the battery pack can be installed
into a device. Once all components are properly placed and connected to one another, they
are sealed with either shrink wrap or a hard case. The housing ensures that the components
remain safely located and provides a clean package for the eventual use by an end user.
The type of housing depends on where the battery pack will be located inside the device
and if it is intended to be accessed by the end-user or a technician.
36. • Lithium battery pack technique refers to the processing, assembly and packaging of
lithium battery pack.
• The process of assembling lithium cells together is called PACK, which can be a single
battery or a
• lithium battery pack connected in series or parallel. The lithium battery pack usually
consists of a plastic
• case, PCM, cell, output electrode, bonding sheet, and other insulating tape, double-coating
tape, etc.
1) Lithium cell: The core of a finished battery
2) PCM (Protection Circuit Model) and BMS (Battery Management System): Protection
functions of over charge, over discharge, over current, short circuit, NTC intelligent
temperature control.
3) Plastic case: the supporting skeleton of the entire battery; Position and fix the PCM;
carry all other non-case parts and limit.
4) Terminal lead: It can provide a variety of terminal wire charging and discharging
interface for a variety of electronic products, energy storage products and backup
power.
5) Nickel sheet/bracket: Connection and fixing component of the cell.
37. • Calculations of battery pack for generating approx. 100 watt energy for approx. 2 hours.
• Single battery with 3.7 V and 2500mAh capacity.
• Using formulae (assuming 80% efficiency of the battery)
time(t)
Efficiency Battery voltage Battery capacity
0.811.1 20
1.776 2Hours
Total required power 100
• Therefore we need 24 cell of batteries with a pack of three (3.7 x 3 = 11.1) pairs in parallel and eight
(2500mAh x 8 = 20Ah) in series combination.
39. 1) Cell Capacity Grading: Capacity Difference≤30mAh After capacity grading, stay still for 48-
72h and then distribute.
2) Voltage Internal Impedance Sorting and Matching: Voltage Difference≤5mV Internal
Impedance Difference≤5mΩ 8 cells with similar voltage internal impedance are distributed
together.
3) Cell Spot Welding: The use of formed nickel strip eliminates the problems of spurious joint,
short circuit, low efficiency and uneven current distribution
4) Welded PCM: Make sure that the circuit board has no leakage components, and the
components have no defective welding.
5) Battery Insulation: Paste the fiber, silicone polyester tape for insulation.
6) Battery Pack Aging: For the quality of the battery, improve the stability, safety and service life
of the lithium battery.
7) PVC Shrink Film: Position the two ends after heat shrinking, then heat shrink the middle part.
Put PVC film in the middle. No whiten after stretching. No hole.
8) Finished Product Performance Test: Voltage：10.8～11.7V Internal Impedance：≤150mΩ
Charge-discharge and overcurrent performance test.
9) Battery Code-spurting: Code-spurting cannot be skewed, and it needs legible handwriting.
40. The major considerations in selecting a battery system are summarized below.
1) Battery Type: Primary, secondary, reserve or fuel cell system.
2) Battery V
oltage: Nominal or operating voltage, maximum/minimum voltage limits, discharge
profile, voltage delay, start-up time.
3) Load Current & Profile: Constant current, constant resistance, or constant power; value of load
current, constant or variable load current.
4) Duty Cycle: Continuous or intermittent, schedule if cycle is intermittent.
5) Temperature Requirements: Operational temperature range.
6) Service Life: Length of time over which operation is required.
7) Physical Requirements: Size, shape, weight limitations.
8) Shelf Life: Allowable storage time.
9) Charge-Discharge Cycle: Discharge profile and charging efficiency.
10)Environmental Conditions: Atmospheric conditions including pressure and humidity, shock, vibration,
spin, acceleration environment compatibility.
11)Safety & Reliability: Permissible failure rates.
12)Maintenance: Ease of battery maintenance and replacement.
13)Cost: Initial and operating costs.
41. Comparative Analysis of Battery
Type
Energy
Efficiency
(%)
Energy
Density(Wh/kg)
Power
Density(W/kg)
Cycle
life(Cycles)
Self-Discharge
Rate
Lead-Acid 70-80 20-35 25 200-2000 Low
Ni-Cd 60-90 40-60 14-180 500-2000 Low
Ni-MH 50-80 60-80 220 <3000 High
Li-ion 70-85 100-200 360 500-2000 Medium
Li-polymer 70 200 250-1000 >1200 Medium
Flywheel
(Steel)
95 May-30 1000 >20000 Very High
Flywheel
(composite
)
95 >50 5000 >20000 Very High
Type
Energy
Efficiency
Energy
Density(Wh/kg)
Power
Density(W/kg)
Cycle
life(Cycles)
Self-Discharge
Rate
Lead-Acid 70-80 20-35 25 200-2000 Low
Ni-Cd 60-90 40-60 14-180 500-2000 Low
Ni-MH 50-80 60-80 220 <3000 High
Li-ion 70-85 100-200 360 500-2000 Medium
Li-polymer 70 200 250-1000 >1200 Medium
Flywheel (Steel) 95 May-30 1000 >20000 Very High
Flywheel (composite) 95 >50 5000 >20000 Very High
44. Noise Factors:
• The main emphasis was on the reduction of noise induced by the asynchronous or synchronous
motor, gear, and inverter, and the improvement of sound quality. research found that resonance is
mainly induced by the second-order excitation associated with the driveline.
• Depending on the operational state of the engine, the source of NVH problems in the engine can
be divided into three categories: start process, idle process, stop process.
• NVH problems, which are frequently encountered during the starting process, are the result of
pump pressure, cranking reaction force, abrupt initial engine-torque, improper torque
compensation, and engine/damper resonant excitation.
• Problems during
• the idling process include battery charging, 1st engine-order combustion force, combustion-
pressure differences, and unstable combustion pressure in the single cylinder.
• During the stopping process of the engine, pump pressure, backward engine rotation, and
improper wheel-torque compensation cause intense vibration of the transmission system.
• The sources of the NVH problems in the electric motor can be divided into electromagnetic and
mechanical noise, aerodynamic noise, and vibration.
• Electromagnetic and mechanical noise include pulse-width modulation harmonics, excessive
electromagnetic harmonics, rotor/bearing/brush and slip ring/commutator friction.
• The aerodynamic noise consists of noise of the fan, the rotating rotor, and airflow noise. Sources
of vibration are the motor, rotor imbalance, bearings, and stator winding. The origin of NVH
problems in the powertrain includes the power-coupling device, clutch, and transmission.
45. Main sources of noise:
• the engine starting/stopping process for HEV.
• The frequent ignition of the engine to charge the battery whenever the SOC is below the
minimum.
• The induced vibration in The powertrain connects engine/motor and frame with elastic and
rigid components.
• Vibration and noise of the power-coupling device.
• The sources of motor noise can be categorized into three types: electromagnetic noise,
aerodynamic noise, and mechanical noise. Electromagnetic noise is either caused by the
PWM harmonic of the power supply control-unit, or by excessive electromagnetic harmonics
coming from the motor. Aerodynamic noise is generated by the fan, the rotor, and the airflow
effect, which is due to airflow when moving along the wind path. Mechanical noise is mainly
caused by the moving rotor, the bearing, and the motor’s brush and slip ring, or commutator
friction.
• The battery is frequently charged and discharged during operation, and various
electromagnetic interference (EMI) noise, such as differential noises, common mode noise,
and radiated noise, are transmitted through power-transmission lines.
46. Classification of Noise:
External Noise:
External noise is defined as the type of Noise which is general externally due
to communication system. External Noise are analysed qualitatively. Now, External Noise may
be classified as
1) Atmospheric Noise: Atmospheric Noise is also known as static noise which is the natural
source of disturbance caused by lightning, discharge in thunderstorm and the natural
disturbances occurring in the nature.
2) Industrial Noise: Sources of Industrial noise are auto-mobiles, aircraft, ignition of electric
motors and switching gear. The main cause of Industrial noise is High voltage wires. These
noises is generally produced by the discharge present in the operations.
3) Extra-terrestrial Noise: Extra-terrestrial Noise exist on the basis of their originating source.
They are subdivided into i) Solar Noise ii) Cosmic Noise.
47. Classification of Noise:
Internal Noise:
Internal Noise are the type of Noise which are generated internally or within the Communication System or in the receiver.
They may be treated qualitatively and can also be reduced or minimized by the proper designing of the system. Internal
Noises are classified as
1) Shot Noise: These Noise are generally arises in the active devices due to the random behaviour of Charge particles or
carries. In case of electron tube, shot Noise is produces due to the random emission of electron form cathodes.
2) Partition Noise: When a circuit is to divide in between two or more paths then the noise generated is known as Partition
noise. The reason for the generation is random fluctuation in the division.
3) Low- Frequency Noise: They are also known as FLICKER NOISE. These type of noise are generally observed at a
frequency range below few kHz. Power spectral density of these noise increases with the decrease in frequency. That
why the name is given Low- Frequency Noise.
4) High- Frequency Noise: These noises are also known TRANSIT- TIME Noise. They are observed in the semi-conductor
devices when the transit time of a charge carrier while crossing a junction is compared with the time period of that
signal.
5) Thermal Noise: Thermal Noise are random and often referred as White Noise or Johnson noise. Thermal noise are
generally observed in the resistor or the sensitive resistive components of a complex impedance due to the random and
rapid movement of molecules or atoms or electrons.
6) Burst noise: Burst noise consists of sudden step-like transitions between two or more discrete voltage and current levels,
as high as several hundred microvolts, at random and unpredictable times. Each shift in offset voltage or current lasts for
several milliseconds to seconds. It is also known a popcorn noise for the popping or crackling sounds it produces in
audio circuits.
7) Transit-time noise: If the time taken by the electrons to travel from emitter to collector in a transistor becomes
comparable to the period of the signal being amplified, that is, at frequencies above VHF and beyond, the transit-time
effect takes place and the noise input impedance of the transistor decreases. From the frequency at which this effect
becomes significant, it increases with frequency and quickly dominates other sources of noise.
48. Battery Packs design against Noise and Vibration exposure
Interface Definition Formed by
Mechanical Mechanical design features included
for safety reasons.
Cell spacers. damping pads. gaskets.
Valves.
Structural Members that provide required
protection and isolation.
Case, cover, end-plates, tie rods,
Members.
Thermal Case, cover, end-plates, tie rods,
Members
Coolant, fans, pumps, heat
exchangers
Electrical Transmits power from, and to, the
battery pack
Bus-ban, cables, contactors, fuse,
relays
Control Monitor and regulate the slate of
battery pack
Battery management system, various
Sensors
Support Vehicle body parts providing additional
crash worthiness
Axles, chassis, seals, vehicle floor
49. Considerations in Battery Packs design against Noise and Vibration exposure
• For battery pack design it has been suggested that the battery temperature must be
maintained below 50°C for safe operation.
• The vibration frequencies of the battery pack should also he suppressed to avoid resonance
at typical natural frequencies of the vehicle suspension system and sprung mass from 0 to 7
Hz, the vehicle powertrain. i.e. driveline and gearbox, from 7 to 20 Hz, and the vehicle
chassis system from 20 to 40 Hz.
• Marginal deviations from the designed boundary can compromise the cycle life of the
battery pack.
• It can also set in motion an uncontrolled chain of exothermic reactions resulting in the
release of smoke or toxic gas and the development of high pressure events leading to
premature failure, fire and explosions.
• These marginal deviations can be caused by excessive heat build-up or physical abuse of
battery packs that includes puncturing or crushing the packs.
• A reliable battery packaging design should address issues relating to thermal stability,
vibration isolation and impact resistance at micro as well as macro level.
50. • Further, it should minimize thermal and mechanical interactions between different units of
the battery pack at each level, i.e. at cell and module level, thus reducing the probability of
failure of the battery pack itself design elements that can be optimized readily to achieve the
required level of protection without which impact on available resources are called control
factors.
• Some of the most critical control factors of an EV battery pack are: battery cells and cell
spacer type. number and location of gas exhaust nozzles, battery cooling system, and
insulation coating thickness.
• battery cell type has a significant influence of design of the battery packs. For example, it
has been found that packing density of a battery Pack with 18650 type cells is 114 times
more than that of a pack comprising large prismatic cells.
• Moreover, the packing density of a pouch cell is approximately 2 times lesser than that of a
prismatic cell of similar nominal capacity mainly because of its smaller thickness and large
surface area. It is therefore relatively easier to improve volumetric efficiency of the battery
pack by packaging large quantities of smaller cylindrical cells in the available space than to
use large prismatic or pouch cells.
51. • Compactness of packaging design also has an appreciable impact on thermal performance of
the battery pack. Research shows that increasing the cell-to-cell spacing for a battery pack
from 1 mm to 10 mm can lead to a loss of approximately 1°C in the steady state cell core
temperature, for all the three physical formats. According to NASA Battery Safety
Requirements Document (JSC 20793 Rev C). cell spacing is more critical for pack designs
employing battery cells of gravimetric energy density greater than 80 Wh/kg.
• It has further been ascertained that to alleviate cell-to-cell heat propagation in the instance of
a single cell failure or a thermal runaway event, a minimum spacing of 2 mm is required for
cylindrical cell formats.
• In addition, a physical harrier between neighboring cells is required for the same reasons in
battery packs that employ cell formats with side vents. Other important design requirements
are specified by various international standards.
52. Structural Stability:
• In the absence of adequate compressive forces needed to maintain uniform contact,
delamination of electrode layers occurs in pouch cell prismatic cells, which affects their
performance and reliability. Delamination of the electrode layers can be avoided through
usage of external structures that may include either hard plates stacked on each side of the
battery cell or clamps made of thread rods. Although the stacking plate method provides
significant advantage during manual assembly of battery packs, it is more expensive on a
mass production basis. Also, holding clamps may make the pouch cells more vulnerable to
mishandling during assembly process and to localized stress development due to unbalanced
clamping force.
• The solid structure created through metallic or rigid plastic casings typically used for the
prismatic and the cylindrical battery cells prevents foreign objects such as nails from
penetrating the electrochemical system. The metallic casings provide a greater degree of
tolerance to pressures generated inside the battery cell because of gas generation and venting;
a safety feature absent in pouch cells owing to their soft packaging. Main structural issue
with the prismatic cells is that their corners can be left vacant due to elliptical windings. It
results in uneven pressure distribution in electrodes but the problem can be alleviated by
filling vacant corners with solid material.
54. ModalAnalysis /Mode Shapes of in battery analysis
• The special initial displacements of a system that cause it to vibrate harmonically are called
`mode shapes' for the system. If a system has several natural frequencies, there is a
corresponding mode of vibration for each natural frequency.
• A mode shape is a deflection pattern related to a particular natural frequency and represents
the relative displacement of all parts of a structure for that particular mode.
• The battery pack in electric vehicles is subjected to road-induced vibration and this vibration
is one of the potential causes of battery pack failure, especially once the road-induced
frequency is close to the natural frequency of the battery when resonance occurs in the cells.
If resonance occurs, it may cause notable structural damage and deformation of cells in the
battery pack.
• The laser scanning vibrometer is used for modal analysis with frequency response functions
(FRF).
• Procedure of mode shape analysis of li-ion battery pack.
1) The un-damped free vibration equation for the system is, MX + SX = 0.
2) natural mode of vibration, the displacement of each mode is calculated by:
Xi = Xi,m × sin(wt + Øi)
55. • where, M is the mass matrix, X is the mass acceleration vectors, S is the stiffness matrix, and
X is the displacement vectors of the modes. w and Øi are the angular frequency and phase
angle of the ith mode. Xi is the matrix of the displacement of the modes, and Xi,m is the vector
of maximum values. If the displacement field of the given structure is harmonic, the Eigen
frequency can be derived. Dictating equations in the study are in terms of the excitation load.
• where, r is the density of the material, w is the angular frequency of the excitation load, and
u is the harmonic response from the structure. The Eigenvalue λ and the Eigen frequencies
f are calculated using Equation
• LIB is held on the shaker and the baseplate is designed in a way to accommodate the
geometry of the battery. the baseplate aims to provide rigid support to the battery and hold
the battery firmly. The baseplate is designed such that the battery fits in easily and the fixture
including the battery does not exceed the weight-bearing limit of the shaker. The material
used for the baseplate is 6061Aluminum and its geometry.
56. • The baseplate is mounted on the shaker using M6 screws to the center of the shaker and is
torqued down with 45 lb/in. Then, the battery is fixed on that plate with clips. To perform
sinusoidal frequency sweeps, a 110 lb MB RED dynamic shaker is used. A signal generator is
used to create input variables.
• Due to restrictions of weight that the dynamic shaker aperture load is 12 lb and the maximum
weight of the apparatus that the aperture arm of the shaker can handle is 11 lb, the weight of the
fixture and apparatus including the battery is determined to be 10 lb. At the test of the structure
mounted aperture arm, the dynamic shaker delivers low noise motion.
• The casing material used all around the flexures to hold the internal components is stainless steel.
Using a set of ultra-flexible multi-strand wire, coil currents are conducted to the coil from which
the shaker receives the signal and responds accordingly.
• The cooling system is provided with a constant field and eliminates the need for a power source,
to reduce the resistive losses of the electromagnet from coil overheating and abate the breakdown
of the coil insulation. The baseplate is then installed onto the aperture arm of the shaker.
• The velocity of the battery is directly measured with laser scanner and the velocity data is
converted to FRF calculations using integrated laser vibrometer. For conducting calculations of
the frequency response function, there is a built-in accelerometer that is attached to the surface of
the dynamic shaker.
64. Component SizingAnd Integration Tradeoffs Performance
• Component sizing : Component sizing is essential to meet the performance
requirements with the optimum resources and at the same time prevents unwanted
wastage of energy resources and losses.
• Modes of sizing
In backward simulation, the desired vehicle speed input goes from the vehicle
dynamic model back to the engine to determine how each component should
perform during the drive cycle operation.
A driver model sends an acceleration or brake signal to different power-train and
component controllers (e.g., throttle for engine, displacement for clutch, gear
number for transmission, or mechanical braking for wheels) in order to follow the
desired vehicle speed trace
67. ELEMENTS OFVEHICLE DYNAMICS
• In vehicle dynamics, the vehicle body (sprung mass), the suspension component (spring and
damper) and tire (unsprung mass) are essential parts of the system.
• Factors affecting vehicle dynamics
1) Drivetrain and braking
2) Suspension and steering
3) Distribution of mass
4) Aerodynamics
5) Tires
• Analysis and Simulation considering spring mass system and using software like ADAMS,
Modelica, CARsim, Simulink etc.
68. DYNAMICS OFTHE MOTOR VEHICLE:
• It is a combine study of interaction between driver, vehicle, road and environment.
• It mainly deals with, the improvement of active safety and driving comfort and the reduction
of road destruction.
• The acceleration of the vehicle depends upon the power delivered by the propulsion unit,
road conditions, aerodynamics shape and mass of the vehicle.
• General description of the vehicle movement like tractive force, rolling resistance,
aerodynamic drag and uphill (grading and acceleration) resistance.
• Longitudinal vehicle dynamics, Forces and motions in longitudinal direction, smooth road
surface Predicting top speed, acceleration and braking performances, gradeability, fuel
consumption...
• Lateral vehicle dynamics, Forces and motions mainly in lateral direction Predicting
cornering performances, handling, stability..
• Vertical vehicle dynamics, Forces and motions mainly in vertical direction Ride, vibration
behavior, tier/road contact...
69. Forces acting on the vehicle
• Gravity effects
• Aerodynamic forces
• Tyre-road interaction
• Tyre behavior (longitudinal and side slip)
• The dynamic equation of vehicle motion along the longitudinal direction
Performance parameters
• Acceleration
• Top speed
• Gradeability
• Breaking performances
• Adhesion, Dynamic wheel radius and slip
71. VEHICLE COORDINATE SYSTEM
Coordinate Systems inAutomated Driving Toolbox
• World:Afixed universal coordinate system in which all vehicles and their sensors are placed.
• Vehicle: Anchored to the ego vehicle. Typically, the vehicle coordinate system is placed on the ground
right below the midpoint of the rear axle.
• Sensor: Specific to a particular sensor, such as a camera or a radar.
• Spatial: Specific to an image captured by a camera. Locations in spatial coordinates are expressed in
units of pixels.
• Pattern:Acheckerboard pattern coordinate system, typically used to calibrate camera sensors.
World Coordinate System
• All vehicles, sensors, and their related coordinate systems are placed in the world coordinate system.
• A world coordinate system is important in global path planning, localization, mapping, and driving
scenario simulation.
• Automated Driving Toolbox uses the right-handed Cartesian world coordinate system defined in ISO
8855, where the Z-axis points up from the ground. Units are in meters.
72. Vehicle Coordinate System
The vehicle coordinate system (XV, YV, ZV) used by Automated Driving Toolbox is anchored to the ego vehicle.
The term ego vehicle refers to the vehicle that contains the sensors that perceive the environment around the
vehicle.
• The XV axis points forward from the vehicle.
• The YV axis points to the left, as viewed when facing forward.
• The ZV axis points up from the ground to maintain the right-handed coordinate system.
The vehicle coordinate system follows the ISO 8855 convention for rotation. Each axis is positive in the clockwise
direction, when looking in the positive direction of that axis.
In most Automated Driving Toolbox functionality, such as cuboid driving scenario simulations and visual
perception algorithms, the origin of the vehicle coordinate system is on the ground, below the midpoint of the rear
axle. In 3D driving scenario simulations, the origin is on ground, below the longitudinal and lateral center of the
vehicle.
Locations in the vehicle coordinate system are expressed in world units, typically meters.
Values returned by individual sensors are transformed into the vehicle coordinate system so that they can be placed
in a unified frame of reference.
For global path planning, localization, mapping, and driving scenario simulation, the state of the vehicle can be
described using the pose of the vehicle. The steering angle of the vehicle is positive in the counterclockwise
direction.
73. Sensor Coordinate System
An automated driving system can contain sensors located anywhere on or in the vehicle.
The location of each sensor contains an origin of its coordinate system. A camera is one type
of sensor used often in an automated driving system. Points represented in a camera
coordinate system are described with the origin located at the optical center of the camera.
74. • The yaw, pitch, and roll angles of sensors follow an ISO convention. These angles have
positive clockwise directions when looking in the positive direction of the Z-, Y-, and X-axes,
respectively.
75. Spatial Coordinate System
Spatial coordinates enable you to specify a location in an image with greater granularity than
pixel coordinates. In the pixel coordinate system, a pixel is treated as a discrete unit, uniquely
identified by an integer row and column pair, such as (3,4). In the spatial coordinate system,
locations in an image are represented in terms of partial pixels, such as (3.3,4.7).
76. Pattern Coordinate System
To estimate the parameters of a monocular camera sensor, a common technique is to calibrate
the camera using multiple images of a calibration pattern, such as a checkerboard. In the
pattern coordinate system, (XP, YP), the XP-axis points to the right and the YP-axis points
down. The checkerboard origin is the bottom-right corner of the top-left square of the
checkerboard. Each checkerboard corner represents another point in the coordinate system. For
example, the corner to the right of the origin is (1,0) and the corner below the origin is (0,1).
77. • Earth fixed coordinate system
Based on earth fixed axis system in which origin is fixed in the ground plane. This axis
system is fixed in the initial reference frame where X and Y are parellal to the ground plane
and z points upwards aligns with gravitational vector.
• Vehicle coordinate system
Based on vehicle axis system with origin located at the vehicle reference point. It is fixed in
the reference frame of the vehicle sprung mass so that x axis is horizontal and forwards with
the vehicle at rest. It is parellal to the vehicle longitudinal plane of symmetry and the Y axis
is perpendicular to the vehicles longitudinal plane of symmetry and points to the left with
the Z axis pointing upward.
78.
79.
80. WHEELANGLES
Primary angles
The primary angles are the basic angle alignment of the wheels relative to each other and to the car
body. These adjustments are the camber, caster and toe. On some cars, not all of these can be adjusted
on every wheel.
These three parameters can be further categorized into front and rear (with no caster on the rear,
typically not being steered wheels). In summary, the parameters are:
• Front: Caster (left & right)
• Front: Camber (left & right)
• Front: Toe (left, right & total)
• Rear: Camber (left & right)
• Rear: Toe (left, right & total)
81. 4-Wheel Caster Steer (all swivels)
This cart configuration can be maneuvered in any
direction. Ideal for confined areas, but needs swivel
lock for traveling long distances in a straight line.
4-Wheel Diamond Pattern (all rigid)
This tilt-type cart configuration rotates or pivots on the center
wheels. This is the lowest cost cart configuration and is suitable
for light loads. This design cannot be pushed sideways.
4-Wheel Caster Steer (2 swivels, 2 rigid)
This cart configuration is the most popular. It is easily turned
or pushed straight and it also trails well.
4-Wheel Diamond Pattern (2 swivels, 2 rigid)
This cart configuration is highly maneuverable and will
rotate in its own length.
Wagon (fifth wheel steer)
This trailer configuration features large axle mounted wheels
for heavy loads. This is usually powered drawn.
6-Wheel Tilt or Non-Tilt (4 swivel, 2 rigid)
This cart configuration is recommended for heavy loads and
extra long trucks. It turns in its own length. The casters on the
corners provide stability.
82. SECONDARYANGLES
The secondary angles include numerous other adjustments, such as:
• SAI (SteeringAxis Inclination) (left & right)
• Included angle (left & right)
• Toe out on turns (left & right)
• Maximum Turns (left & right)
• Toe curve change (left & right)
• Track width difference
• Wheelbase difference
• Front ride height (left & right)
• Rear ride height (left & right)
• Frame angle
• Setback (front & rear)
85. Battery Thermal Management System (BTMS)
• EV battery pack thermal management is needed for three basic reasons:
• To ensure the pack operates in the desired temperature range for optimum performance and working life. A typical temperature
range is 15-35°C.
• To reduce uneven temperature distribution in the cells. Temperature differences should be less than 3-4C°.
• To eliminate potential hazards related to uncontrolled temperature, e.g. thermal runaway.
• The electric vehicle has a battery management system (BMS) to provide essential information such as:
• Thermal Protection
• Over and Under voltage protection
• Over-current Protection
• Prolong battery life
• Cell Balancing
• SoC and SoH calculation
• Communication with all battery components
• Data acquisition and analysis
• The high battery temperature leads to poor performance, short lifetime, and risk of blasting. Therefore, a BTMS is essential for
all battery modules.
• The main purpose of a BTMS is to maintain the battery system in the optimum temperature range and keep uniform temperature
variation in the battery modules
• Other factors for battery selection are weight, size, reliability, and the cost
• The following figure shows the most used thermal management techniques for battery module
87. • Batteries work based on the principle of a voltage differential, and at high temperatures, the
electrons inside become excited which decreases the difference in voltage between the two sides of
the battery.
• Because batteries are only manufactured to work between certain temperature extremes, they will
stop working if there is no cooling system to keep it in a working range.
• Cooling systems need to be able to keep the battery pack in the temperature range of about 20-40
degrees Celsius, as well as keep the temperature difference within the battery pack to a minimum
(no more than 5 degrees Celsius).
• Potential thermal stability issues, such as capacity degradation, thermal runaway, and fire
explosion, could occur if the battery overheats or if there is non-uniform temperature distribution
in the battery pack.
• In the face of life-threatening safety issues, innovation is continually happening in the electric
vehicle industry to improve the battery cooling system.
• There Are A Few Options To Cool An Electric Car Battery—with Phase Change Material, Fins,
Air, OrALiquid Coolant.
• The Determining Features Of An Electric Vehicle Battery Cooling System Are Temperature Range
And Uniformity, Energy Efficiency, Size, Weight, And Ease Of Usage (I.E. Implementation,
Maintenance).
88. • Phase change material absorbs heat energy by changing state from solid to liquid. While
changing phase, the material can absorb large amounts of heat with little change in
temperature. Phase change material cooling systems can meet the cooling requirements of
the battery pack, however, the volume change that occurs during a phase change restricts
its application. Also, phase change material can only absorb heat generated, not transfer it
away, which means that it won’t be able to reduce overall temperature as well as other
systems. Although not favorable for use in vehicles, phase change materials can be useful
for improving thermal performance in buildings by reducing internal temperature
fluctuations and reducing peak cooling loads.
89.
90. • Cooling fins increase surface area to increase the rate of heat transfer. Heat is transferred
from the battery pack to the fin through conduction, and from the fin to the air through
convection. Fins have high thermal conductivity and can achieve cooling goals, but they
add a lot of additional weight to the pack. The use of fins has found a lot of success in
electronics, and traditionally they have been used as an additional cooling system on
internal combustion engine vehicles. Using fins to cool the electric car battery has fallen
out of favor since the additional weight of the fins outweighs the cooling benefits.
91. • Air cooling uses the principle of convection to transfer heat away from the battery pack.
As air runs over the surface, it will carry away the heat emitted by the pack. Air cooling is
simple and easy, but not very efficient and relatively crude compared to liquid cooling. Air
cooling is used in earlier versions of electric cars, such as the Nissan Leaf. As electric cars
are now being used more commonly, safety issues have arisen with purely air-cooled
battery packs, particularly in hot climates. Other car manufacturers, such as Tesla, insist
that liquid cooling is the safest method.
92.
93. • Liquid coolants have higher heat conductivity and heat capacity (ability to store heat in the
form of energy in its bonds) than air, and therefore performs very effectively and own
advantages like compact structure and ease of arrangement. Out of these options, liquid
coolants will deliver the best performance for maintaining a battery pack in the correct
temperature range and uniformity. Liquid cooling systems have their own share of safety
issues related to leaking and disposal, as glycol can be dangerous for the environment if
handled improperly. These systems are currently used by Tesla, Jaguar, and BMW, to name
a few.
94.
95. • In Liquid Cooling Systems, There Is Another Division Between Direct And Indirect
Cooling—whether The Cells Are Submerged In The Liquid Or If The Liquid Is Pumped
Through Pipes.
• Direct cooling systems place the battery cells in direct contact with the coolant liquid.
These thermal management schemes are currently in the research and development stage,
with no cars on the market using this system. Direct cooling is more difficult to achieve,
due to the fact that a new type of coolant is required. Because the battery is in contact with
the liquid, the coolant needs to have low to no conductivity.
• Indirect cooling systems are similar to ICE cooling systems in that both circulate liquid
coolant through a series of metal pipes. However, the construction of the cooling system
will look much different in electric vehicles. The structure of the cooling system that
achieves maximum temperature uniformity is dependent on the shape of the battery pack
and will look different for each car manufacturer.
96.
97. Future Of EV Battery Cooling
• Since electric vehicles have become so widely used, there is a high demand for longer
battery life and higher power output.
• To achieve this, the battery thermal management systems will need to be able to transfer
heat away from the battery pack as they are charged and discharged at higher rates.
• The heat generated as the battery is used can pose safety threats to the passengers.
• Due to the high stress and temperatures generated by the batteries, there is even higher
importance on having the correct coolant and additive package.
• While companies such as Tesla, BMW, and LG Chem can use a traditional liquid coolant
for their indirect cooling systems, continued research and development will need to be
done on battery packs and coolants to advance electric vehicle safety.
98. Assignment 2
1. Define energy storages, explain with its classifications?
2. List and explain battery Energy Storage System Components?
3. Explain the constructional details of li-ion battery with its advantages, disadvantages and
applications?
4. Explain the constructional details of Ni-Cd battery with its advantages, disadvantages and
applications?
5. Explain the constructional details of lead acid battery with its advantages, disadvantages
and applications?
6. List and explain the components of li-ion battery pack?
7. List and explain the steps involved in formation of li-ion battery pack?
8. What are the major considerations in selecting a battery system?
9. Compare lead acid, nickel and lithium batteries on basis of cost, energy efficiency,
temperature performance, weight and life cycle?
10. Explain NVH analysis with its importance in electric vehicles?
11. Explain noise factors with its main sources and classification?
12. Explain Battery Packs design and considerations against Noise and Vibration exposure?
13. Compare of structural characteristics of different types of battery cells?
14. Explain the Modal Analysis /Mode Shapes of in battery analysis with its experimental
steps?
15. Explain vehicle dynamics with its elements and affecting factors?
16. Explain vehicle coordinate system with suitable sketch?
17. Explain briefly Cooling System and Thermal Management?
18. Explain Battery Thermal Management System?
19. Explain different types of battery cooling with its significance?
20. Compare types of battery cooling with its advantages and disadvantages?
