With the increasing demand for crude oil and rising prices, it has become necessary to look for alternate energy sources, and this search led to the development of EVs worldwide. With the established and routine use of electric four-wheelers now, it has extended to the manufacturing of 2 wheelers. The central government, apart from providing subsidies to the EV manufacturers and buyers, thought of the difficulty faced by the users in getting them charged. Apart from the increasing number of charging stations in the coming future, with the increased number of vehicles, it may be difficult in cities to provide a place for charging stations for so many vehicles. In last August 2021, the government gave the option for the manufacturers to manufacture two-wheeler EVs with or without batteries. During this fiscal 2022-23 budget, a new Battery swapping policy has been introduced to reduce the cost of EVs and quick replacement of batteries, thereby promoting their usage. Few states in India are providing subsidies and incentives for battery swapping stations. Various companies which have come forward to establish these stations are Sunmobility, ChargeUp, Lithion power, Reliance-British BP joint venture and Hero MotoCorp with Taiwan’s Gorgo. With NITI Aayog and Rocky Mountain Institute’s prediction that by 2030, 80% of two- and three-wheelers and 50% of the country’s four-wheelers will be electric vehicles. Hence, it becomes necessary to develop safety and protective measures.
Types of batteries
Lithium batteries are used for EVs instead of lead batteries due to its high specific charge density (lasts longer and stores more energy) and huge voltage (3- 3.5 Volts /battery). In Lithium-ion batteries, there are two types–traditional Li-NMC batteries, where the cathode is a mixture of NMC (Nickle, Manganese and cobalt) and LFP (Lithium Iron phosphate), where the cathode is LiFePo4 (Lithium Iron Phosphate). The difference between the two types of lithium batteries is explained below in Table.1.
In this annum, nearly ten accidents have occurred (Fig.1 & Table.2). With the government providing subsidies and incentives, many start-up companies have come forward with most of the batteries imported from other nations. The market of EVs has risen threefold, with 1,34,821 units sold in fiscal 2020-21 to nearly 4,29,417 units being sold in the 2021-22 fiscal year. The various reasons proposed for the increased accidents are described below:
1. Poor quality of cell design: Each battery of lithium-ion contains nearly 100-200 cells. If they are not packed properly, the anode, cathode and the separator may come into contact leading to a short circuit.
2. Poor battery design: Here, the insulation may not be proper, and the wires may not be connected properly, leading to a short circuit.
3. Cheap quality BMS (Battery Management system): whenever the battery gets heated up, there should be a system within it to sense and start countermeasures to cool up the system. If an efficient BMS is lacking, it leads to short circuits and fire accidents.
4. Smart management system and thermal management system: In a smart management system, not only the temperature of the battery but the temperature of every cell is kept under surveillance, and any rise in temperatures is countered by a thermal or active cooling system where fans are activated around the battery to cool the system.
Measures to be taken while purchasing and maintenance of the EVs
1. Don’t expose the EVs to extreme hot or cold temperatures
2. Use original and authorised charges
3. Keep batteries away from inflammable elements
4. Store batteries at room temperature only
5. Check whether batteries are getting overheated
6. Don’t charge the battery to 100% or allow to discharge to less than 20%, try to maintain charge between 20-80%
7. While purchasing EVs, purchase battery from authorised dealers only
8. Check whether EVs and battery are certified by ARAI (Automotive Research Association of India)
9. Check whether the battery is of AIS 156 standard
As soon as the accident occurred on March 26, MoRTH has ordered for investigation by the Centre for Fire, Explosive and Environment Safety (CFEES), an agency under DRDO. Also, the government has asked original equipment manufacturers to recall the vehicles and check for any defaults. As a result, around 7000 vehicles have been recalled by various companies (Fig.2). Also, the government is trying to develop new testing norms for batteries, cells and management systems. Alternate energy sources like the green hydrogen batteries are in the investigative phase.
It becomes necessary for every customer to look into the batteries and go for the premium ones which fit into the standards described rather than running for cheaper ones. LFP batteries are to be preferred in place of NMC batteries. Better BMS with superior intelligence which can act at the right time during raised temperatures. By proper checking on software and hardware systems in the batteries and with proper precautions, we need to move further in utilising the EVs.