Batteries contribute to 30–50 per cent of the cost of an EV, and are the equivalent to a fuel tank in a petrol-based vehicle. The difference is that a battery is much more expensive, weighs more, and is larger in volume. Without a battery, an electric vehicle would be less expensive than a petrol vehicle.
While filling petrol only takes two to five minutes, charging an EV without impacting its battery life takes five hours. More expensive batteries can be fast charged but that too takes about an hour. Batteries that can be charged in ten to fifteen minutes are considerably more expensive. A small EV battery limits the vehicle’s range and causes range anxiety for potential EV owners. A large battery with sufficient capacity will help alleviate concerns on range, but it increases the price of the EV considerably by XX in comparison to a small battery. To tackle this issue and make EVs affordable, the Government of India enabled battery swapping in August 2020.
The EV can either be purchased without the battery, reducing the cost of the vehicle, or an energy operator (EO) can purchase, charge, and swap the battery in a few minutes, making it easier for an EV owner to use a small battery so that swapping is easier and the EO business becomes viable.  [aj2]
For a public vehicle like an e-rickshaw with a 60 km range battery, a couple of swaps in a day may be acceptable. A city bus may swap batteries at the end terminus. However, a private vehicle owner is unlikely to swap their vehicle’s battery every day and may need to use range extension (RE) battery-swap. If a car with a 100 kms fixed battery travels between 20 km and 70 km on most days, charging the fixed battery overnight may be enough. If the car needs to travel more than 100 kms, it can add a 100 kms RE battery at a battery swapping station and travel 200 kms. For longer distances, another RE battery can be added, making long-distance travel without charging on the way feasible.
An EV without its battery costs less than an equivalent petrol vehicle, and the cost of leasing a charged battery per km is less than the cost of petrol per km . As an example, let us look at an auto (three wheeler). A petrol auto will cost ₹2 lakhs, whereas an electric auto without battery will cost ₹1.75 lakhs. The charges per km for petrol auto will be ₹2.50 per km. Battery swapping can be done at ₹1.75 per km. With such charges, the business providing battery swapping is profitable too. In other words, the electric vehicles without battery would cost equal to or less than petrol vehicles. The operation cost per km would be less than the cost per km of petrol vehicle. Thus, Battery swapping becomes a powerful instrument for countries like India to accelerate their shift to EVs.