A) Battery swapping Pros and Cons
Battery swapping has been a topic that is very controversial in the EV industry. It offers one major advantage - rapid "charging" of the EV. The process is very simple, you drive to a swapping station with your EV, drive on a platform, the battery is swapped automatically and you drive away. But it has several disadvantages which are as follows:
1. Battery pack design
One of the first issues that battery swapping technology faces is battery design. In battery swapping, the batteries must be easily accessible and located in a single pack. This problem is solved with the under-body "skateboard" design (such as in the Tesla Model S), in which the battery pack is a flat structure underneath the vehicle.
When disconnecting and reconnecting several times the power leads and cooling system equipment, the battery pack has to be designed in a specific way so as it can be easily and rapidly removed from the vehicle, and so rapidly re-attached.
2. Compatibility
For a technology to succeed and become a dominant trend, one feature is absolutely essential: Cross Platform / Brand Compatibility. For battery swapping to ever have a chance at becoming a mainstream technology, interchangeable battery packs that are similar for various manufacturers must be found. Manufacturers all design their vehicles based on proprietary designs.
Using all a standard format battery pack would limit the manufacturer's flexibility and innovation. Also, there are several battery cell manufacturers and each car manufacturer usually sides with a single supplier for his cells. Having a standard platform would mean that even the cell manufacturers will opt to manufacture similar cells, thus limiting product development and innovation.
One can argue that there might be different power segments for the battery pack, but this would then create a problem with supply and demand and also, possible compatibility issues with vehicles not designed for higher or lower powered battery packs.
3. Infrastructure
The infrastructure required for the battery packs is immense and much more complex and expensive than charging. First of all, all battery swapping stations must charge their battery packs - so they exert the same demand on the grid as in charging stations, with the only difference that the demand can be controlled (even though in practical terms, it is essential for all battery packs to be charged as rapidly as possible, so that they are available for the next customer.
Second, they must have a number of battery packs that exceeds by a certain percentage the daily requirement for each station. This means that for every car there must be at least 2 battery packs - one inside the car and another one available in a battery swapping station. This increases the costs of the vehicles tremendously, as it is a fact that the battery packs are the most expensive component in an EV.
Also, cost of the battery swapping stations will be very high, and they have to cover the country well. When all is considered, the cost of setting up a nationwide battery swapping system versus a nationwide car charging system is much more expensive, so eventually, less likely to happen.
4. Battery Degradation
Battery performance degrades over time, and as a result the range attainable with each charge. In a battery swap scenario, considering that all cars will be using the same battery pack format and power, we will find batteries with different energy storage capacities in the swapping station, mainly due to degradation.
Logically, most people will opt for newer battery packs when swapping, as they give greater range and reduce the number of trips required to the swapping station.
Lower capacity packs means that range with EVs will not be the same as with new packs, so users will not be happy when their new battery pack is swapped with a lower performance pack, as they will get less mileage from their vehicle.
This will result in batteries having shorter operating cycles, as in order to keep customers happy, battery packs with reduced performance would be replaced faster, increasing the recycling cost drastically.
5. Battery Ownership
A logical question is: In battery swapping who owns the battery? There are two ways to look at it:
The vehicle owner owns the battery - When a user goes to a battery swapping station, his battery is removed, one from the charging station is installed on his vehicle and while he is on his way, his battery is recharged. Upon his return to the swapping station, the original battery is re-installed on the vehicle.
The advantage of this method means that the owner of the vehicle is also the owner of the battery, and has access to other batteries when required to speed up his trips.
However this system has several disadvantages. The first is that the owner has to go to the same location to pick up his original battery pack. The most probable solution will be that the driver will opt to charge his vehicle. Thus battery swapping is not suitable.
Also, this means that the manufacturer has to produce a higher number of batteries in order to sustain the network, as the vehicle owners will go to their original location to pick up their battery - so said battery cannot be utilized on another vehicle. It will stay in the charging station until its owner reclaims it.
The vehicle owner does not own the battery - This scenario has major advantages on the previous scenario. Not owning the battery means that the EV price would be more accessible, and to the contrary of the battery owning scenario, once a battery is swapped, the driver doesn't need to go back to retrieve it.
This gives extreme flexibility. But even here there is a major downturn: since the battery is not owned, each time a battery is swapped the vehicle owner will pay, in addition for the energy, also a lease on the battery.
This lease can be either constant (a value per month) or with every battery swap. If the lease is monthly (or yearly), this means a higher cost of ownership of the vehicle as the lease amount must cover the cost of two battery packs and also the swapping station.
6. Demand and supply of Batteries at charging stations
As demand for batteries and battery swapping centers increases there are chances of cost overruns due to transportation of batteries from one center to another. Since batteries are heavy, there will be additional cost involved in transportation (further increasing the operational cost of battery ownership)