battery calculations for electric vehicle

All the parameters, equations, results and plots are implemented in a Scilab (*.sce) file. eta_p is the efficiency of the powertrain. The battery parameters have a significant influence on other components and attributes of the vehicle, like: Pretty much all major aspects of a pure electric vehicle (EV) depend on the parameters of the high voltage battery. Energy consumption depends on aerodynamic drag, mass, velocity, acceleration, coefficient of friction, and grade of road. 31. The total number of strings of the battery pack Nsb [-] is calculated by dividing the battery pack total energy Ebp [Wh] to the energy content of a string Ebs [Wh]. These batteries are specifically designed for a high ampere-hour (or kilowatt-hour) capacity. Energy requirement from the battery can be calculated by backward facing model of electric vehicle To extend the life of the battery pack, we do not want to discharge the batteries more than 80%. The number of strings must be an integer. Let's start calculate the battery capacity for 200km travel on 20kmph speed: The current withdraw by bldc motor on 20kmph is 5amp. and intermittent loads (heater, brake lights, wipers, etc.) Because of the low capacity for the cylindrical cells, compared to the pouch cells, the number of cells required for the battery pack is significant higher. For our electric vehicle battery design we are going to start from 4 core input parameters: A battery consists of one or more electrochemical cells (battery cells) which are converting chemical energy into electrical energy (during discharging) and electrical energy into chemical energy (during charging). Energy density of each cell, Volumetric and gravitational energy density are to swapped. ), which will increase both the final volume and mass. As with ICE (Internal Combustion Engine) vehicles, speed, distance, MPG, etc.. will vary between vehicles due to driving habits, road. The results of the equations (7) to (20) are summarised in the table below. The energy content of a string Ebs [Wh] is equal with the product between the number of battery cells connected in series Ncs [-] and the energy of a battery cell Ebc [Wh]. Therefore, the result of the calculation is rounded to the higher integer. With the above cell parameters and the core requirements for the battery (nominal voltage, average energy consumption and vehicle range), we calculate the main parameters of the high voltage battery. Electric carmakers have long been clamoring for a battery breakthrough that will improve the range of their vehicles while also extending their lifespans. These batteries are usually rechargeable (secondary) batteries, and are typically lithium-ion batteries. You can also check your results using the calculator below. the equations are not readable. For example, if the same 20 Ah battery is discharged in one hour, it can only deliver 12.4 A for one hour, which amounts to 12.4 Ah. Voltage! There is usually little difference in a battery's 10Ah and 20Ah rating so it doesn't have a big impact on the pack size. The paper presents the simulation of a basic electric vehicle motor-drive system that is used to investigate power flow during both motoring and regeneration. For our application we are going to consider a nominal voltage of 400 V. In the article EV design – energy consumption we have calculated the average energy consumption for propulsion Ep as being 137.8 Wh/km on WLTC drive cycle. And for those looking to add a generator as a range extender..... Lastly, the subject of heaters. document.getElementById("comment").setAttribute("id","ade81b54fce56490a189696c6b628816");document.getElementById("e4df9a918e").setAttribute("id","comment"); Dear user, An electric-vehicle battery (EVB) (also known as a traction battery) is a battery used to power the electric motors of a battery electric vehicle (BEV) or hybrid electric vehicle (HEV). Currently, most manufacturers are offering 8-year/100,000-mile warranties for their batteries. after that, divide battery capacity by motor average current rating. The same results can be plotted in bar graphs for an easier comparison between the different types of battery cells. Battery size â Select the battery size of the electric vehicle which should be considered in the calculation. 1. A high number of cells might cause additional problems in areas of wiring, voltage monitoring, battery reliability. Comparatively Assessing different Shapes of Lithium-ion Battery Cells. In terms of mass and volume there is no clear distinction between cylindrical and pouch cells. How to calculate nominal battery voltage(Ubp)? 2017 Nissan LEAF Battery electric vehicles (BEVs) have a battery instead of a gasoline tank, and an electric motor instead of an internal combustion engine (ICE).. During these uncertain times, Carvana is dedicated to ensuring safety for all of our customers.In addition to our 100% online shopping and selling experience that allows all customers to buy and trade their cars without â¦ Along with the energy consumption of the vehicle, it determines the battery size required to achieve a given electric range. Like the engines in conventional vehicles, the advanced batteries in EVs are designed for a long life but will wear out eventually. The 25th World Battery, Hybrid and Fuel Cell Electric Vehicle Symposium & Exhibition It can be noted that the factor 0.8 occurs a number of times in the calculations: battery charging is 80% efficient, 80% of the nominal battery capacity is utilised and the electric power train has an efficiency of 80%, as is illustrated by Figure 3. The prolonged electrical loads (headlights, multimedia, etc.) load current = ( ( max. The high voltage battery it is one of the most important component of a battery electric vehicle (BEV). The first method is using a 220 volt AC electric power to charge five series batteries; each battery has 12 VDC (35 A/h) to supply totally 60 VDC input voltage for the electronic inverter which converts 60 VDC to 60 VAC (three-phase voltage) as a controllable voltage source to three-phase synchronous motor (SM) type (BLDC-YG1-ZZ-1200 W). This calculation method is more appropriate for cylindrical cell, since the volume occupied by a cylindrical cell must take into account the air gap between cells. The high voltage battery pack of Mitsubishi i-MiEV consists of 22 modules made up from 88 cells connected in series. [4] https://industrial.panasonic.com/ [5] http://www.a123systems.com/ [6] http://www.molicel.com/ [7] http://www.a123systems.com/ [8] http://www.toshiba.com/ [9] http://www.kokam.com/. QUALITY ELECTRIC VEHICLE CONVERSIONS AND QUALITY. [1] Mooy, Robert & Aydemir, Muhammed & Seliger, Günther. BP – battery pack * – taking into account only battery cells. Thank you! first calculate the rated current of the motor, peak current , load current. Electric vehicle battery lifespan. We can now recalculate the battery pack total energy Ebp [Wh] as the product between number of strings Nsb [-] and the energy content of each string Ebs [Wh]. The battery is a fundamental component of electric vehicles, which represent a step forward towards sustainable mobility. Electric Vehicle Conversions: What’s - What? If we divide it to the length of the WLTC driving cycle (23.266 km), we get an average energy consumption for the auxiliary loads Eaux of 9.241 Wh/km. Can you please tell me where the E_avg equation is coming from? BDC – Bollettino del Centro Calza Bini – Università degli Studi di Napoli Federico II. Therefore you’ll multiply (Ep+Eaux) with 1.2. For download please subscribe to the Patreon page. Higher voltage comes in handy when going up hills- a long drawn out hill (remember a 5% grade doubles power needed) can easily, Now we get to the fun part, calculating HP. In order to increase the current capability the battery capacity, more strings have to be connected in parallel. The battery pack peak current Ibpp [A] is the product between the string peak current Ispc [A] and the number of strings of the battery pack Nsb [-]. Maybe there is another way of doing this but the rationale is the same. To extend the life of the battery pack, we, , just because you raise the voltage so high or don't need a long range, you should not use batteries much lower than. Specific power is a characteristic of the battery chemistry and packaging. Consideration the acceleration losses is about 5% for low traffic Effective current = 5 x 1.05 = 5.25amp Choose the socket youâre charging from or manually adjust voltage and amperage; 4. an electric motor and battery power can provide the majority of the population an all electric commuter car for under $10,000. The total number of cells of the battery pack Ncb [-] is calculated as the product between the number of strings Nsb [-] and the number of cells in a string Ncs [-]. For automotive applications there are different types of cells used [1]: Image: Different shapes of Lithium-ion battery cellsCredit: [1]. The battery pack continuous power Pbpc [W] is the product between battery pack continuous current Ibpc [A] and the battery pack voltage Ubp [V]. From the table data we can see that the pouch type cell have better energy content and higher capacity compared with the cylindrical cells. 14. The required battery size $B_{lead-acid}$ for lead-acid batteries is calculated by the battery size calculator as: 104-111. All high voltage battery packs are made up from battery cells arranged in strings and modules. The battery pack peak power Pbpp [W] is the product between battery pack peak current Ibpp [A] and the battery pack voltage Ubp [V]. Elsevier Butterworth-Heinemann, 2004, page 129. However, several research points are still open. The Electric vehicle (EV) is very similar to the road vehicle which involves with electric propulsion. The size and mass of the high voltage battery are very important parameter to consider when designing a battery electric vehicle (BEV). This is less important since the aim or the article is to explain how the calculation is done. The mass and volume are calculated only at cell level, taking into account the cell dimensions and mass. Direct current is a source which is used in all type of motors in electric vehicles to drive the wheels. The battery pack continuous current Ibpc [A] is the product between the string continuous current Iscc [A] and the number of strings of the battery pack Nsb [-]. Today, electric vehicles have lithium-ion batteries, yet slow-moving electric vehicles are equipped with lead batteries as well. As for energy and capacity, the pouch type cells have higher peak (continuous) current and power than cylindrical cells. For this example weâll design the high voltage battery pack for a vehicle range of 250 km. The higher the voltage of your Battery System, the faster a given EV can go. It works for all unassisted electric vehicles such as electric scooters and electric bicycles when using the power of the motor only (no efforts provided by the rider). The ChargeHub Calculator lets you estimate the money you would save by driving an electric vehicle, according to your region and driving habits. Please support us by disabling your Ad blocker for our site. Lithium chemistry is now acknowledged as the technology of choice for energy storage in electric vehicles. Technological solutions aiming at recovering metro braking energy: a multi-criteria analysis case study. The first battery electric vehicles that will appear on the market are passenger cars in the lower car segments. The following calculations are going to be performed for each cell type. (2017). A battery cell consists of five major components: electrodes – anode and cathode, separators, terminals, electrolyte and a case or enclosure. The string continuous current Iscc [A] is the product between the continuous C-rate of the battery cell C-ratebcc [h-1] and the battery cell capacity Cbc [Ah]. use on average 430 W of electrical power. zebra battery. For example, the total (string) voltage of 6 cells connected in series will be the sum of their individual voltage. â¢Power Density (W/L)â The maximum available power per unit volume. In practice, the charging time for an electric car battery may vary between 10 hours to half an hour.Sure, it's longer than filling up a conventional car. A large drawback of metal air batteries is their low specific power, needed to give enough power to drive the electric vehicle. The battery cell energy Ebc [Wh] is calculated as: where: Cbc [Ah] – battery cell capacity Ubc [V] – battery cell voltage. Check your browser Javascript settings or try a different browser. The volume of each cell is calculated as: where: Dbc [m] – battery cell diameter Lbc [m] – battery cell length, where: Hbc [m] – battery cell height Wbc [m] – battery cell width Tbc [m] – battery cell thickness. For this example we are going to consider that the battery pack is made up only from several strings connected in parallel. Based on the cell parameters provided by the manufacturers, we can calculate the energy content, volume, gravimetric density and volumetric density for each cell. Pick an electric car from the dropdown list; 2. [3] Tom Denton, Automobile Electrical and Electronic Systems, Third edition. The Range per Charge is 300Wh per mile which is typical of a normal car. Electric vehicle; Electric vehicle battery; Kilowatt hour; Battery pack; Supercharger; EV battery basics: All you need to know about kW, kWh, and charging speed. Then you can use the calculator on this pageâ¦ I went ahead an found out using the Inverter Calculator that you are pulling 52.90 Amps DC and hour our of the battery pack. For this exercise we are going to use an average efficiency ηp of 0.9 from the battery to the wheel. Also, the electric motor and driveline have some losses which we need to consider. The input parameters of the battery cells are summarised in table below. During the infancy of the automobile, electric and gasoline vehicles competed for dominance of the market. 10.1016/j.promfg.2017.02.013. That is a high draw if you plan on running off a battery for any length of time. In order to calculate the size of the battery we need two main inputs: the average energy consumption and the range of the vehicle. The high voltage battery of an electric vehicle (EV) is one of the most important components since it dictates the dynamic performance, range and charging time of the vehicle. However it seems that a battery pack with pouch cells is slightly heavier and bigger. Replacing the values in (2) gives the average energy consumption: The battery pack will be designed for an average energy consumption of 161.7451 Wh/km. The number of strings must be an integer. 301-325. The equations should be readable. The following calculations are going to be performed for each cell type. power to weight ratio ) /motor voltage ) * total load on the vehicle. A 5% grade requires twice the power that is needed on level roads. #allaboutevehiclesThis tutorial explains about the range (mileage) calculation of lithium ion battery for an electric vehicle. The battery pack mass (cells only) mbp [kg] is the product between the total number of cells Ncb [-] and the mass of each battery cell mbc [kg]. [2] Bernardini, Annalia & Barrero, Ricardo & Macharis, Cathy & Van Mierlo, Joeri. That is instead of Volumetric energy density it should be Gravitational energy density. Set the current and desired state of charge (20-80% by default); 3. This conversion is taking place with an associated loss. This volume is only used to estimate the final volume of the battery pack, since it does not take into account the auxiliary components/systems of the battery. Can you please mention the source for all equations. Generally you need about 2500-3000 watts to raise the temp in a car to a comfortable level in a, copyright 2011 EV-propulsion llc Thanks to Dustin O. for editing work. Nevertheless by looking only at cell based volume and mass, we can estimate which model will be better compared to the other. The battery size calculator derates the battery linearly based in this characteristic. In order to have a better overview of the cells parameters and to compare them easier, the main parameters are displayed as bar graphs in the images below. There are several types of batteries (chemistry) used in hybrid and electric vehicle propulsion systems but we are going to consider only Lithium-ion cells. this is it! The duration of the WLTC cycle is 1800 s (0.5 h), which gives an energy of 215 Wh for the auxiliary loads. Based on the calculated data and conclusions, we can choose which battery cells are suitable for our electric vehicle battery pack. Even if Wh/km is not really energy but factorised energy, since it’s dived per unit of distance (km), for simplicity, we are going to refer to it as average energy. The number of battery cells connected in series Ncs [-] in a string is calculated by dividing the nominal battery pack voltage Ubp [V] to the voltage of each battery cell Ubc [V]. Everything depends on the charging point used and the battery capacity of your electric car. In this example we are going to caclulate the volume of the battery pack considering only the battery cells. IF I HAVE 620 volts lithium ion battery pack, how much HP motor is required to generate 1450 RPM?. The battery cells manufactured by A123-Systems have very high maximum continuous discharge current and maximum pulse (peak) discharge current. Image: Battery pack total number of cells. Image: Ragone diagram cell level adapted from Van Den Bossche 2009Credit: [2]. why does it have (2-n) in it? The calculation is: Volts x (Amp Draw / MPH ) = Wh/m Battery Pack Size (KWH): Pack Voltage x Amp-Hour rating of battery = KWH Usable Battery Pack Size: Unfortunately, we can not use all of our battery Pack or we will kill our batteries extremely fast. that involve no CO2 emissions. The voltage of each cell is 3.7 V and the total voltage of the battery pack 330 V. Image: Battery pack (modules and cells)Credit: Mitsubishi. It's easier than it looks. Light Electric Vehicle Online Range Calculator We designed this online range calculator to debunk all the lies, myths and misconceptions regarding the range of light electric vehicles. If you want to calculate the charging time of a completely empty battery, select 0%. Speed, Pack KWh rating, driving conditions, aerodynamics, vehicle weight, hills, temperature, driving styles and several other factors, *note: there are adjustments that have to be made to this formula, see usable pack size below*, Unfortunately, we can not use all of our battery Pack or we will kill our batteries extremely fast. The type of elements contained within a battery and the chemical reactions during discharging-charging events define the chemistry of a battery. If an electric automobile is equipped with lead batteries for a â¦ The volume can be also calculated function of number of strings and number of cells in a string. Another example is the high voltage battery pack of Tesla Model S, which has: Image: Tesla Model S battery packCredit: Tesla. Individual battery cells may be grouped in parallel and / or series as modules. For this example we’ll design the high voltage battery pack for a vehicle range of 250 km. Energy required to move an electric vehicle from one point to another comprises of many factors. The main reason is that Li-ion batteries have higher specific energy [Wh/kg] and specific power [W/kg] compared with other types [2]. And 1.2 comes from 2-0.8. Lead batteries increase the weight of an electric vehicle the most, compared with the other kinds of batteries. Note: Since battery cells manufacturers come up with newer models continuously, it might be the case that the data used in this example is obsolete. The same method can be applied for any other battery cells. The simulation assumes a DC permanent magnet motor, an ideal motor controller combined with a proportional-integral controller, and the electric vehicle battery. A battery cell can be regarded as the smallest division of the voltage. The required battery pack total energy E bp [Wh] is calculated as the product between the average energy consumption E avg [Wh/km] and vehicle range D v [km]. The battery pack capacity Cbp [Ah] is calculated as the product between the number of strings Nsb [-] and the capacity of the battery cell Cbc [Ah]. Choose the battery size in kWh. how can i view those as they are? The direct current (DC) supplied by the battery is converted into alternated current (AC) by the inverter. The required battery pack total energy Ebp [Wh] is calculated as the product between the average energy consumption Eavg [Wh/km] and vehicle range Dv [km]. An electric vehicle's battery capacity is measured in kilowatt-hours (kWh), the same unit your home electric meter records to determine your monthly electric bill. The string peak current Ispc [A] is the product between the peak C-rate of the battery cell C-ratebcp [h-1] and the battery cell capacity Cbc [Ah]. On top of the energy needed for propulsion, the high voltage battery must supply the energy for the vehicle’s auxiliary devices Eaux [Wh/km], like: 12 V electrical system, heating, cooling, etc. Also, we have to consider the efficiency of the powertrain ηp [-] during the conversion from electrical energy to mechanical energy. why does it extracts from 2? From our examples it looks like Kokam cells have the best compromise between mass, volume and energy/power density. In reality there are other factors to consider, like: electronic circuits, cooling circuit, battery casing, wiring, etc. The volume of the battery pack (cells only) Vbp [m3] is the product between the total number of cells Ncb [-] and the mass of each battery cell Vcc(pc) [m3]. The total battery pack voltage is determined by the number of cells in series. thank you in advance! The battery cell energy density is calculated as: The energy density for each cells are summarised in the table below. Further, battery modules can be connected in parallel and / or series to create a battery pack. Tesla expected to unveil âModel 2â electric hatchback in late 2021 posted on February 5, 2021; Images of new Audi e-tron GT emerge online ahead of official launch posted on February 8, 2021; Angus Taylorâs electric vehicle emissions claims âfundamentally flawed,â says expert posted on February 8, 2021 In order to chose what battery cells our pack will have, we’ll analyse several battery cells models available on the market. 10.6092/2284-4732/2929. A common criticism of electric vehicles regarding emissions is that they simply transfer the CO2 emissions to the power plant. Procedia Manufacturing. For this example we are going to focus only on Lithium-ion cells. In most of the cases the electric current has been supplied from the battery in the electrical vehicle [2]. After 2020 the metal air batteries can be possible candidates for electric vehicles. How to calculate wheel torque from engine torque, Linear interpolation and extrapolation with calculator, Vehicle acceleration and performance online calculator, average energy consumption of the vehicle on a driving cycle. The obvious argument is that the grid power is produced from a variety of means - like hydro, wind, geothermal, nuclear, solar, etc. That means that the computer's range prediction is derived from translating the remaining battery charge into kilometres, based on the remaining charge as a percentage of the total battery capacity and how long the vehicle has travelled so far on that charge. The higher the current, the bigger the diameter of the high voltage wires and the higher the thermal losses. Each module contains 4 prismatic cells. 8. For this reason, the current should be limited to a maximum and the nominal power obtained by having a higher voltage. The battery pack which will be in the vehicle will have additional components (wires, electronic components, soldering, case, etc. If the efficiency is let’s say 80% (0.8), this means that you have to provision 20% extra energy in the battery. If you want to calculate the cost of charging, fill in how much you pay per kWh of electricity. Specific energy is a characteristic of the battery chemistry and packaging. For example, 3 strings connected in parallel will triple the capacity and current capability of the battery pack. Starting charge level â This percentage corresponds to the level of the battery at the beginning of the process. Lithium iron phosphate batteries may be the new normal for electric cars, which could lower EV prices and ease consumer fears about the cost of replacing a battery. That calculator will tell you how many amps you are pulling out of the battery. (2015). Our website provides free and high quality content by displaying ads to our visitors. Therefore, the result of the calculation is rounded to the higher integer. The all electric vehicle lost because of the lack of range from current battery â¦ Depending on the battery parameters, there may be several levels of modularity. For the auxiliary devices energy consumption we are going to use data from [3], which contains the typical power requirements of some common vehicle electrical components (auxiliary loads). Image: Battery cell volumetric energy density, Image: Battery cell gravimetric energy density. Peer-review under responsibility of Applied Energy Innovation Institute doi: 10.1016/j.egypro.2015.07.199 Energy Procedia 75 ( 2015 ) 1920 ââ¬â 1925 ScienceDirect The 7th International Conference on Applied Energy ââ¬â ICAE2015 A review of SOH estimation methods in Lithium-ion batteries for electric vehicle applications Cheng Lina, Aihua Tanga,b* ,Wenwei Wanga â¦