Newly Introduced Battery Electric Vehicles
An electric car is a one powered by an electric motor rather than a traditional petrol/diesel engine. This electric motor is powered by rechargeable batteries that can be charged by common household electricity. Fully electric cars are powered 100% by an electric motor and battery. Fully electric cars do not burn gasoline or diesel and have zero tailpipe emissions. Most fully electric cars can travel 200-250 km on a full charge, with some models capable of 400+ km. There are several electric cars which will be launching in next year and the future will be full of electric automotive. Here I mentioned three electric vehicles with their batter pack configuration, specifications and details about battery management system for particular EV (Electric Vehicle).
The three electric vehicles are:
- Ford Focus Electric
- Audi E-tron
- Tesla Model 3
These vehicles are already launched in 2018 and some are predicted to launch in 2019.
Ford Focus Electric
The Ford Focus BEV was the concept electric car introduced by Ford Motor Company at the 2009 Frankfurt Motor Show but the current 2018 model has various key features. Ford used a complete electric drive train developed and supplied by Magna International and the advanced lithium-ion battery system is being engineered by Ford in cooperation with supplier Compact Power, Inc.
Battery Pack Configuration
The Focus Electric shares Ford’s global C-car platform and is built using the body of the third generation Ford Focus. The Ford Focus EV is powered by an electric motor rated at 107 kW, 245 Nm (143 hp, 181 ft-lbs), and uses a 23 kWh (75Ah) capacity LG Chem lithium-ion battery pack consisting of 430 cells arranged in 86 series 5 parallel (86S5P) connection. The nominal cell voltage is 3.7 V with a 4.2/3.0V maximum/minimum voltage. The nominal pack voltage is 318.2 V and weighs 667 lbs (Appx. 302.5 kg). It is split into two parts, one part being under the rear seats and the other one is mounted behind the rear seats. The Focus EV delivers 92 kW (125 PS; 123 bhp) and 181 lb⋅ft (245 N⋅m) of torque. Focus Electric weighs approximately around 600 (272 kg) to 700 pounds (317 kg).
Thermal Management System
Ford Focus EV has an advanced active liquid-cooling and heating system to regulate the temperature of its battery packs, which are designed to operate under a range of ambient conditions. This active liquid system heats/cools a coolant before pumping it through the battery cooling system. This loop normalises temperature throughout the system against external conditions. In summer, cool water absorbs heat from the batteries, circulate it through a radiator before pumping it through the cooler again. In winter, heated water warms the batteries, gradually bringing the system’s temperature to a certain level that allows it to efficiently accept charge energy and provide enough discharge power for expected vehicle performance.
The liquid cooling system also plays a role in charging the vehicle. When the all-electric Focus is plugged into recharge, the vehicle control system will automatically precondition the battery, to the ideal temperature before accepting charge. If the battery is already at the ideal temperature, the system will automatically accept charge and maintain an ideal temperature.
Audi E-tron (SUV)
Audi E-tron is first mass market electric car from Audi to the world. The 2019 Audi e-tron is an SUV targeted to the Tesla Model X, but it will also compete with the Jaguar I-Pace and Mercedes-Benz EQC.
Battery Pack Configuration
Audi designed a flat box of 432 cells that live under the 2019 e-tron’s floor, between its front and rear axles and electric motors. The battery pack measures 5.3 feet wide, 13.4 inches high, and 7.5 feet long. The mostly flat pack has a higher section that sits under the e-tron’s rear seat, where it has additional battery capacity. The battery pack weighs around 715 kg, or more than 1,573 pounds. There are 36 battery modules in each pack. In each module, Audi E-tron’s battery packed with 12 pouch-style 60 Ah (3.5 volt) cells, for a total of 432 cells. It has 95 kWh of battery-pack which is capable to drive 400 km or 248.5 miles. E-tron will become the first volume-produced electric car compatible with 150-kilowatt charging, which is capable of surfing the battery with an 80 percent charge (roughly 200 miles) in half an hour.
Thermal Management System
Audi E-tron SUV has unique thermal management system. Thermal management system has a set of thermal circuits filled with anti-freeze forms a sort of cooling bed frame for the e-tron battery pack. It’s sealed and thinly sandwiched in under the pack. That prevents more damage should the circuit burst in an accident. Thermal adhesive fastens the cooling circuit to the battery pack, and a thermally responsive gel cushions the cells inside the pack.The pack pulls cooling capacity from the air and from the anti-freeze liquid circuit.
Under temperate conditions, the e-tron battery pack modulates temperature with air from intakes and a radiator that all guided by electronically controlled louvers that direct airflow. Under more extreme conditions, a chiller acts as a heat exchanger for the cooling circuit. It maintains battery temperatures between 77 and 95 degrees so the battery can be fast-charged repeatedly and quickly at a high charging rate. There is a limitation for Audi E-tron battery pack. It can only maintain those temperatures when the vehicle is in use, or when it’s plugged in for charging.
Tesla Model 3
The Model 3 was codenamed Tesla BlueStar in the original business plan in 2007. The intended name was Model E that was abandoned due to Ford trademark. Model 3, originally stylized as "Model ☰". The Tesla Model 3 is a mid-size (US) / compact executive (EU) luxury all-electric four-door sedan manufactured and sold by Tesla.
Battery Pack Configuration
Tesla manufactured various variants of Tesla Model 3. Each variant has different battery configuration, features and range. The base Model 3 has a 50-kWh battery with a range of about 220 mi (350 km) and the optional 75-kWh battery has a range of about 310 mi (500 km). The Model 3 battery pack uses Tesla’s next generation 2170 cells (21mm width, 70mm height) that contains 30 to 33% more energy compared to previous generation’s 18650 cells.
Tesla and Panasonic’s joint R&D made the new 2170 battery cell. This next generation battery is smaller, more efficient, simpler and easier to maintain.The battery container packed with 4,416 cylinder cells (2170) in to four modules that weigh around 1054 lbs/478 kg combined. The two modules on either side are 67.5 in (1715 mm) long and weight 191 lbs (86.6 kg) each and the two center modules are a bit longer and heavier i.e. 73 in (1854 mm) and 207 lbs (98.9 kg). All four modules are 11.5 in (292 mm) wide and 3.5 in (90 mm) thick. Each module has cells grouped into a brick of 46 cells (cylinders).
The small modules have 23 bricks and large ones (center) have 25 bricks of cells each.Model 3 battery pack modules are tightly concealed in hard plastic and heavily bolted to the ground for the safety of the cells and related electrical and electronic systems. Each module has its own BMS circuit. The pack is center tapped. Each module is about 235 lb. The modules are sealed in a metal box. Inside, each module is encased in plastic enclosures with mechanical connections to the outer box. These probably serve the dual purpose of electrical isolation and fire resistance. The cells are electrically connected at the top with fusible links to a complex shaped flat metal conductor. The fusible links bear a strong resemblance to large bond wires used in semiconductor power devices.
Thermal Management System
The Model 3 battery module is machine assembled. Each length of tube with cells attached is nicknamed a “bandolero”. The cooling tube in each bandolero only has to cool 164 cells. The cooling tube is bigger than Model S/X cooling tubes (cells are larger) and can pass more glycol cooling flow. The tube also covers a higher percentage of the cells’ height. One cooling module contains seven bandoleros. The seven bandoleros are then connected in parallel that results better cooling than the old series design and, as mentioned, each pass only cools 164 cells.
Reasons for better battery cooling in Tesla Model 3
Better heat transfer between the cells and the cooling ribbon because the cells are glued directly to the cooling ribbon and the cooling ribbon spans a greater percentage of the cells’ height.
References:
- Ford Focus Electric - https://en.wikipedia.org/wiki/Ford_Focus_Electric
- http://www.greencarcongress.com/2010/09/thermal-management-system-for-the-ford-focus-ev- battery-pack.html
- Audi E-tron SUV - https://www.greencarreports.com/news/1116347_audi-details-battery-for-2019-e-tron-electric-suv
- Tesla Model 3 - https://en.wikipedia.org/wiki/Tesla_Model_3
- https://insideevs.com/tesla-model-3-battery-pack-in-depth/
- https://insideevs.com/tesla-model-3-battery-cooling-track-mode/
