Evolution Of Battery (Energy) Swapping
Old Age Swappable Energy
When we talk about battery swapping, it indirectly means energy swapping only which is stored in batteries.
For understanding this process of energy swapping, we need to travel back a bit more in the history of mobility, as it evolved from the early days of civilization. Energy swapping, per se, has been a big challenge since the time humans found faster alternatives to move as compared to walking.
It was the time when animals (primarily horses) were used for long-distance movements or for load carrying. Since animals by nature have a limited range of travel due to their biological & physical constraints (they need rest & food to recoup their energy), arrangements were made at regular distances in those early times to change these animals (or in other words swapped) to ensure that the journeys could be completed at a steady pace.
Such relay stations also had a set of trained people to keep these animals, fit & healthy. These places allowed the tired animals to rest and recover, while allowing people to continue their onward journey by using new animals, without breaking their journey. This in a way, was the very first energy swapping station albeit of a different kind where depleted energy source (tired animals) was swapped with rejuvenated energy source (well rested & well fed animals).
The pattern continued during the times of steam engines, when the energy swapping/refilling was done in the form of loading of coal & water which were required by the steam engines. During this time, complex network of coal & water replenishment systems evolved.
This refilling of coal & water was also a form of energy swapping for the mobility machines of those times. Historically, horse changing (swapping) & Coal/ water refilling systems were important aspects of transportation and logistics before the advent of automobiles.
This changing of horses was a skill, so was the coal & water filling, requiring good coordination, as well as knowledge of the multiple systems & could truly be called the origin of present day battery (energy) swapping for future EVs.
Now, considering the similarity of these energy charging & gas refilling as a process of energy replenishment, we need to understand the challenge of EVs since the early 1900s when they were ruling the mobility world.
Present Day Battery (Energy) Swapping
Coming back to modern day EVs, battery swapping has a great level of similarity with these energy swapping systems of by gone era & conforms to the same purpose – as it was in good old days when the horses were replaced/ coal-water was replenished, to fasten the journeys & reduce the idle time.
The battery swapping of present-day EVs, need to serve the same purpose & in the late 19th century, many automotive companies began experimenting with the idea of quick replacement of batteries.
The Milburn Wagon Company[2] (founded in 1848 in Toledo, Ohio), was one of the more successful electric car makers of that time, producing thousands of vehicles between 1914 and 1922.
In 1915 they introduced a battery swap-out system, which had batteries on rollers that allowed the owner to “roll out” the discharged batteries and “roll in” the charged ones. President Wilson’s Secret Service staff used Milburns. Later in 1923, General Motors (GM) bought the Milburn factory and used it to make Buicks cars, yet the Milburns were produced on a “custom-order” till as late as 1927.
Another company, the Electric Cab and Carriage Service was launched in New York in 1897 by two Philadelphia engineers, Henry Morris and Pedro Salom, and backed by the Electric Storage Battery Company. In 1899, as the sales increased, it renamed itself the EV Company (EVC).
Unfortunately, in those times, most of the batteries were with LABs (Lead Acid Battery) which were disproportionately heavy, weighing around 1,600 pounds each, and the cars’ shells could barely cope with this added weight.
Moreover, these LABs were prone to leak corrosive fluids damaging the car bodies.
Since electricity was a new invention in early 1900, the charging/ swapping facilities were also limited. It was time when an EV drove into the station, technicians had to pull out the 2.600 kg battery tray, using a hydraulic piston, and then used an overhead crane to lift it from the table and deposited it in the charging room. The new battery was put back using the reverse process for the cab to move out on the roads.
In 1907, predictably, EVC folded and it was a year later that Henry Ford launched his famous “Model T”. Some of these electric cabs continued to run in New York City until 1912, BUT by 1919 the EVs market share fell to just 1% of all commercial vehicles in the US, and virtually no private EV cars due to the massive success of “Model T” and discovery of cheap oil in Texas (period known as “Texas Oil Boom”). However, the charm of EVs never died and the search continued to find a lightweight battery alternative to the heavy LAB.
It was a quest that took almost seventy years to reach its goal when Lithium Ion Battery (LIB) could be commercially made available. However, it is understood that there were still many converted EVs that were used in taxis in Spain till WW-II – these converted EVs were using LAB due to “Shortage of Fuel” in Europe.
This system was the earliest example of an “Exchangeable Battery Service” system developed by the French company “La Societe des Moteurs Bollée” in the early 1900s, which allowed EV drivers to quickly “swap out” depleted batteries for fully charged ones at designated battery-swapping stations. Unfortunately, affordability of ICEVs & cheap oil did not allow it to gain widespread acceptance.
Around the same time (between 1910~1924), an electrical utility company in the US, by the name of Hartford Electric Light Company[4], through its sister company GeVeCo battery service, was serving electric trucks with what is known as the earliest battery swapping service of modern times.
The vehicle owners purchased the vehicle, without a battery, from General Vehicle Company (GeVeCo), part-owned by General Electric. The energy was purchased from Hartford Electric & batteries were charged which were sold as exchangeable batteries. Both vehicles and batteries were designed to facilitate a fast exchange.
The owner paid a variable per-mile charge and a monthly service fee to cover vehicle maintenance and storage. These vehicles covered more than 6 million miles despite the fact that early Milburns[5] only had a useful range of 90 to 120 kms. A 1918 literature advertisement stated “THE BATTERIES ARE NOW ON ROLLERS THAT OPERATE ON TRACKS, SIMPLY ROLL OUT THE DISCHARGED ONES AND ROLL IN THE FRESHLY CHARGED SET.
| Some of the advertisements done by GeV eCo in the early days of electric vehicles | ||||
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| Some Of The Early Battery Swapping Stations | ||||
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A similar service was operated for owners of Milburn Light electric cars in Chicago[6]. In the 1970s, Mercedes tested battery swapping and built about 40 electric buses with a manual horizontal battery swapping system (see Figure 2) but concluded that the technology was not safe. Due to these quality concerns, the project was not continued[7].
Thomas Weber, the chief of R&D at Mercedes, said that the system tested by them was very dangerous, as electrocution could occur easily during the manual change. They tested these 40 trucks very rigorously, with a manual horizontal battery swapping system. Back in 1970, when the electronics were primitive Weber had a point on electrocution. Added to the precautions of electrocution, there was the issue of the battery’s quality.
The concept of an intelligent charging and discharging mechanism, telling the customer what the state of the battery is, must have been out of science fiction in those times, so was to tell about the charging station, its battery parameters, and reliability for a next minimum of miles. Weber said that every electric car has to have its own battery and this should have an autonomy of about 125 miles, being recharged in a maximum of 15 minutes up to 80%. Weber also said that the battery technology to achieve this won’t be commercially viable until 10 years from now (remember it was 1970).
| Mercedes Trying Battery Swap On Electric Buses Back In The 70s |
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| Some Of Early EVs With Swappable Batteries, One Also By Thomas A. Edison |
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Above are the cut sections of chassis of early EVs by General Vehicle (GeVeCo) chassis from Long Island City, New York, 1911 with electric motor in the rear, with chain drive of rear wheel & battery pack mounted at bottom for easy replacement.
| Evolution Of EVs from early Henney Kilowatt to GM’s Exotic to Tesla’s Model S |
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Evolution of Lithium-Ion Battery (LIB)
Lithium is the lightest of all metals and has the greatest electrochemical potential to provide the largest energy density for weight but Lithium metal also has inherent instability during charging when used in the battery.
In early 1970, M. Stanley Whittingham discovered the process to control this charging instability. However, he could not make this rechargeable lithium battery a practical one. During 1974~76, a process of reversible intercalation[8] in graphite and intercalation into cathodic oxides was discovered by J. O. Besenhard who proposed its application in lithium cells.
The research work continued on these cells and in 1991 when a Japanese team at Sony, led by Yoshio Nishi successfully released the first commercialized lithium-ion battery (LIB).
The development of LIB technology was considered to be so revolutionary that in 2019, the Nobel Prize in Chemistry was awarded to John Goodenough, Stanley Whittingham, and Akira Yoshino “for the same.
Though these batteries are called LIBs, in real terms they do not have any Lithium as metal but as an intercalated lithium compound. These LIBs are extensively used in modern EVs, however, battery technology analyst Mark Ellis of Munro & Associates sees three distinct LIB form factors & their combination that would be used in future EVs:
- a) cylindrical cells (e.g., Tesla),
- b) prismatic pouch (e.g., from LG), and
- c) prismatic can cells (e.g., from LG, Samsung, Panasonic, and others).
Compared to any other battery technology, LIB technology had many advantages such as high energy density, no need for prolonged priming when new, relatively low self-discharge, low maintenance, can provide the very high current needed during quick acceleration, no memory & also higher cell voltage (3.6v) which compensated few of its demerits such as it is subjected to aging, even if not in use, requires protection to maintain voltage and current & it is expensive to manufacture 9albiet the cost is coming down as the technology is maturing).
One of the biggest advantages of LIB technology is its flexibility in size & form factor. The LIB can be manufactured in the shape & size needed to meet any specific requirement with desired working voltages & energy densities.
| Lithium-Ion Battery (LIB) | |||||
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| Lithium Polymer Battery (LPB) | |||||
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Return Of EVs With Swappable Batteries
With the battery technology (LIB) available, offering excellent energy density & also flexibility creating a battery with an unbound form factor, in 1993, Suntera[9][10] developed a two-seat 3-wheel electric vehicle called the SUNRAY, which came with a battery cartridge that could be “swapped out” in minutes at a battery-swap station. In 1995, Suntera also added a motor scooter. The company was later renamed Personal Electric Transports (PET).
After 2000 the company developed an electric bus. In 2004, the company’s 3-wheel stand-up EV won 1st place at the 5-day long American Tour de Sol electric vehicle race. Unfortunately, the company closed in 2006. Some smaller automakers attempted to popularize battery swapping with individual cities but could not succeed.
| Sunray EV With Swappable Battery Cartridge (Front) |
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Zotye Auto built a fleet 15 of M300 EV hatchbacks for a taxi fleet in Hangzhou, China. In 2011, one of these vehicles burnt after the battery pack in the trunk caught fire. An investigation later found that fault in the battery and also pointed out that the battery connecting terminals had worn out due to repeated loading and unloading of charged battery packs.
| Zotye M300 EV & Battery Swapping (Rear) |
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In recent times, another company that tried to revive battery swapping albeit in a different way was Better Place[11], a company started by Shai Agassi[12] of Israel in 2007 when it developed and started settling battery charging and battery switching services for electric cars.
The company’s setup was able to replace depleted batteries with fully charged ones at designated battery swapping stations very quickly. Despite being an old idea in the age of mobile phones, his idea of quick battery swapping for electric cars was an instant hit, and since it was the right time when venture capitalists were looking for some great idea, it is found in Better Place.
The funds started pouring in & the company began to expand rapidly throughout the world. With growth beyond expectation, Better Place announced the deployment of EV networks in Israel, Denmark, and Hawaii in 2008 and 2009.
The company planned to deploy the infrastructure on a country-by-country basis and went on to initiate talks with more than 25 additional regions around the world. Australia, Ontario, Oregon, and California also announced the deployment of their own EV networks.
Riding on success, in January 2008, Better Place announced a memorandum of understanding with Renault-Nissan to build the world’s first Electric Recharge Grid Operator (ERGO) model for Israel. Under the agreement, Better Place would build the “Electric Recharge Grid”, and Renault-Nissan would provide the custom-built EVs. Unfortunately, the growth of Better Place was much hyped and unsustainable over the long period due to the high investment required to develop the charging and swapping infrastructure.
Market penetration of Better Place was significantly lower than originally predicted by Shai Agassi, who expected 100,000 cars on Israeli roads by 2010 which never crossed 1,000. A total of 948 Better Place branded Fluence Z.E.[13] cars were deployed in Israel and around 400 units were sold in Denmark by May 2013, when Better Place filed for bankruptcy.
Under Better Place’s business model, the company owned the batteries of Fluence Z.E. Customer never owned the battery and hence there was a risk of being left with a useless car in case Better Place was unable to supply a charged battery under the replacement plan.
It must be noted that the Renault Fluence Z.E. was the electric version of the Renault Fluence compact sedan, part of the Renault Z.E. program of BEVs. It was unveiled by Renault at the 2009 Frankfurt Motor Show. The Fluence Z.E. was fitted with a 22 kWh LIB which allowed it travel range of about 185 km (with maximum speeds up to 135 kmph).
It was the first modern electric car known to be enabled with battery swapping technology and was deployed within the Better Place network in Israel and Denmark in 2012. Fluence Z.E. was built at the Oyak-Renault plant in Bursa, Turkey & as it was phased out, a fixed-battery version called Renault Samsung SM3 ZE was launched in South Korea. It was one of the most popular electric cars in South Korea in the mid-2010s, with thousands sold through 2017.
Global sales totaled 10,600 units through December 2019, mostly composed of SM3 Z.E. units.
Battery Swapping Present Day Scenario
Now with the evolution of battery technologies and by being in operation for quite some time the battery swapping technology has also seen many cyclic changes.
With the recent evolution of the whole ecosystem, battery swapping is becoming a practical solution for the mass EV market, with better load & energy management. Today, with the rising number of EVs on the roads, it is gaining popularity as new-age EVs have also evolved into an acceptable alternative to ICEVs.
Many companies like NIO Power (China), Gogoro (Taiwan), Immotor (China), Aulton (China), and Sun Mobility (India) are the leading players and are now creating dedicated battery swapping stations to make it easier for drivers to switch out their batteries.
The Battery swapping technology today is a highly innovative field both from core electronics point of view to highly complex power gird & load management as well as energy balancing (between conventional & renewable energies) point of view.
Overall, while battery swapping technology has the potential to improve the convenience and cost-effectiveness of EVs, more testing and research are needed for its scalability, ease of operation with safety to make improve its acceptability.
| Better Place Battery-Swap Station | Geely Battery-Swap Station |
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| Nio Battery Swap Station | Battery Swapping Of Gogoro & Foxconn |
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In the late 1990s, while the 4W EV market was still evolving, battery swapping technology saw the emergence of another segment of automobiles i.e. 2W & 3W sectors. Taiwan-based company Gogoro (2011) began to develop and deploy battery swapping technology for their electric scooters, which allowed riders to quickly switch out their drained batteries with fully charged ones.
These battery packs were then charged at the convenience of the charge station at the time when the gird tariff was lower and/or using green energies were generated far away and pumped to these charging stations.
These stations were charging nominal fees to charge these battery packs of 2W & 3W. Some other companies like Bird and Lime, are also experimenting with battery swapping for electric scooters and even bicycles for which batteries could be quickly swapped out with fully charged ones, allowing the scooters to remain in service for longer periods of time.
| BAIC Battery Swapping Station | Standardized And Fully Automated NIO Battery Swapping Station | ||
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| NIO Scooter With Its Power Board | Operation Of Tesla Battery-Swapping | ||
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Broad Timelines Of Key Events In The Evolution Of EV’s Battery Swapping
The Benefits Of Battery Swapping [“Battery As A Service (BaaS)”]
Battery swapping offers several benefits for electric vehicle (EV) owners and the environment. Here are some of the key advantages of battery swapping:
Increased Availability
A fast and convenient way to recharge EVs, increasing their availability and reducing the downtime associated with traditional charging methods.
Eliminates Range Anxiety
Eliminates range anxiety, one of the biggest challenges associated with EV ownership, by providing a quick and easy way to replace a depleted battery with a fully charged one.
Battery Inspection
Allows for frequent inspection of batteries, which can help optimize their utilization and extend their lifespan.
Standalone Cost-Effective Infrastructure
Stations can be unitized & built more cheaply, similar to Gas filling stations. With better harvesting of Solar & Wind Power, these stand along charging stations can be made to store electricity – generated from these renewable energy sources, eliminating the complete back-end power infrastructure.
Environmental Benefits
Battery swapping is also helpful in reducing the environmental impact of EVs, as it eliminates the random charging & later disposal of used batteries. Additionally, in combination with renewable energies and these charging stations can help to reduce the overall demand for electricity from conventional resources.
Faster Charging
It can be designed for a much faster rate of charging, thus reducing the overall energy replenishment time of EVs.
Flexibility
It offers flexibility for EV owners, as they can choose between charging their battery or swapping it out depending on their needs and preferences.
Longer Vehicle Lifespan
It can potentially increase the physical use life of EVs per se, as it will allow the upgrading of battery to a newer and higher-capacity battery in times to come (albeit in the same form factor).
Challenges & Future Of Battery Swapping
Battery swapping is an innovative technology having its own issues, many of them are critical yet if handled properly, it will be of great help in pushing the EV transition.
Each of these challenges needs specific attention for this technology to come into the mainstream. As the EV industry continues to evolve, battery swapping technology will also continue to evolve to play an important role in shaping the future of transportation. Some of these challenges are listed below:
Standardization/ Limited Battery Types
Battery swapping requires a standard battery design and size, which can be challenging for OEMs, given the variety of EV models and manufacturers in the market. Ensuring compatibility and interoperability between different OEMs is essential for battery swapping to be widely adopted.
This is one of the most important factors as when done, the 2W & 3W manufacturers will have to design their vehicles around such standardized battery form rather than the present way of vehicle design, in which once the vehicle design is complete, the battery is designed to fit in the space available.
Limited Availability & Poor Maintenance
Battery swapping stations are not always readily available, especially in remote areas where EVs are more likely to be used. Even if these stations are made available, many times they cease to function as there are no people to operate & maintain them.
Expensive Infrastructure
Establishing battery swapping stations requires significant investment in infrastructure, including land, equipment, and trained personnel.
Safety
Battery swapping involves handling large amounts of portable electrical energy, requiring robust safety protocols for the safety of personnel.
There is also a risk of fire or explosion if batteries are not handled properly and/ or charging stations are not maintained properly, which could pose a threat to general public safety.
Safety of this setup is extremely critical as compared to a petrol pump where stored energy is visible whereas in the EV charging stations, the electrical energy is not visible. Moreover, electricity itself is still not well understood in India where about 30 people die every day because of electrocution[18].
Homologation Challenge
A big safety challenge will come in the form of crash safety when these batteries would be owned, maintained & charged by someone else but would be used by multiple users.
Battery Terminal Connections
With frequent battery swapping, maintaining good high-current connections of these batteries within the battery compartment would also be extremely critical to avoid dangerous overheating and arcing on the power connections.
High Cost Of Swapping Station
Creating a battery charging system even for a reasonable number of vehicles requires a heavy investment – both locally as well as at the power grid level, supporting them.
Epilogue
Addressing these challenges will be key to the widespread adoption and success of battery swapping technology which has the potential to transform the way we power our EVs, but it’s essential to address the challenges and risks before implementing the technology widely.
Despite these challenges, battery swapping is an exciting area of the present-day mobility sector and it is certainly required for EV transition.
As battery technology advances and more manufacturers adopt battery-swapping systems, we can expect the technology to become more widely used in the years ahead, bringing benefits like faster charging, greater availability, and reduced range anxiety to EV owners. It has the potential to play an important role in the growth of EVs market, overcoming the most common issue of common man which is “range anxiety”.
On the flip side, the advancement of battery technology in the field of solid-state batteries also brings a dramatically opposite point of view as with the arrival of solid-state batteries, the need for battery swapping technology may itself get reduced.
This is due to fact that the solid-state batteries can be quickly charged and also have a longer lifespan, reducing the need for frequent battery swaps or even the charging of the battery itself.
Overall, while battery swapping technology has the potential to improve the convenience and cost-effectiveness of EVs, it still needs to overcome several obstacles as well as future technological development in the field of battery technologies.
Despite the challenges, the future of Battery swapping in India looks promising, with several key players entering the market. The overall market for Battery swapping in India is expected to grow rapidly in the coming years.
According to a report by Niti Aayog, the demand for Battery swapping in India is projected to reach 25~30 GWh by 2025 and 50-60 GWh by 2030. This presents a significant opportunity for Battery swapping providers to establish themselves in the Indian market and contribute to the growth of the EV industry.
