To swap or not to swap: What’s best for electric vehicles
battery and the E2W/E3W and reduces the expenses incurred by EV owners.
Need for swapping
The plug-in chargers for Electric Vehicles (EV’s) are slow and are capable of charging a single vehicle at a time. The vehicles can be mostly charged at home or work and charging type is typically 2 hours or more.
Separation of vehicle and battery, reduces the upfront cost of EV purchase, enhances the competitiveness. The standardised battery can improve the safety and prolong the life of the battery by correct charging. User’s also generally don’t need to worry about the residual value of the battery or the battery degradation. They can continue to enjoy the dividends brought about by improvements in battery technology. With centralized management of batteries and closed-loop management, reduces the overall cost of the batteries. The batteries can also be re-purposed after their end-of-life for solar and energy storage applications.
Battery Swapping Standards
Gogoro of Taiwan is the world leader in battery swapping stations. Gogoro has over 2000 GoStations and has delivered over 180 million battery swaps to more than 375,000 subscribers. Most recently Gogoro has partnered with Hero MotoCorp for building the next generation of smart vehicles powered by Gogoro swapping technology.
Figure 1: Gogoro swapping stations. Picture credit: Gogoro
Taiwan E-scooter standard (TES) was formulated to ensure standardisation in battery and battery swap stations. Gogoro has engineered safer, swappable batteries and connected it all on a network of battery swapping stations that intelligently distribute energy so that the battery power is always available, when and where needed. Gogoro has developed vehicles so that the battery packs are unstealable and comes with over-the-air software updates. The network of swapping stations is all scalable and flexible with a small foot-print.
Gogoro’s goal is to shift perceptions of what electric fuel could be. Each Gogoro e-scooter connects two Li-Ion batteries, weighs about 9kg each and offers riding distances of up to 170km. They are encased in a durable, waterproof, aluminum case and every battery in the network is monitored with over 25 integrated sensors for thermal, overcharge protection, shock detection and equipped with wireless NFC communication.
The Gogoro Charging Stations (GoStations) are modular, consisting of a main unit with additional expansion units that can be added as needed. The larger GoStations can retain up to 200kWh of energy, supporting upto 1000 riders. They are accessible 24×7 in places like gas stations and convenience stores. The touchscreen provides information about users’ energy use and displays notifications about their EV usage. The typical expectation is that the users can swap their batteries and go in under 30 seconds.
The swapping stations can also power themselves using batteries in the event of power interruption or can be used as a power source to help power smaller microgrids in the event of power outages disrupting critical systems. The consumers who like Gogoro’s battery system will have a choice between buying Gogoro’s own scooters or scooters from third parties. Gogoro’s ridesharing platform can be used as a white-label solution by companies that want to launch their own EV ride-sharing program.
Honda, KTM, Yamaha and Piaggio Group have formed a Swappable Battery Motorcycle Consortium (SBMC). The underlying aim is to address the future of electro mobility, such as range, charging time, infrastructure and cost of ownership. They are developing common technical specifications for swappable battery systems.
Vehicle Battery Charger Cloud Protocol (LS-VBCC) formulated by Indian Institute of Technology Madras (IITM) under the Chairmanship of Prof Ashok Jhunjhunwala of Prof Ashok Jhunjhunwala published the open protocol for battery swapping. This protocol document addresses the Charging protocol (between charger and battery), Driving protocol (between battery and vehicle) and provides protocol for communication between Electric Vehicle (EV) and Electric Vehicle Supply Equipment (EVSE) and for communication between EVSE and a Central Management System (CMS). The Central Management System (CMS) design incorporates open-APIs enabling development of mobile applications, so as to provide a holistic platform for enabling EV proliferation.
Figure 2: LS-VBCC Battery Swapping Architecture
The physical layer is based on the CAN interface (29-bit CAN identifier at 500kbits/sec). The CAN identifier is as per the SAE J1939-21:2006 standard. The protocol includes an auto-addressing stage to address the various devices in the system and also includes an authentication stage so that only after proper device authentication, other transactions are honoured. The detailed protocol document is available for free download.
Lack of standards for battery swapping, lack of openness and divergent technical and economic interests are the key challenges. Also safety is a key concern that needs to be addressed in the battery swapping stations. A common swapping policy for promoting battery swapping technology is key. Other impediments are the large investment requirement for battery-swapping stations, operation and maintenance of the swapping stations, difficulty in achieving unified standards, unclear demarcation of division of responsibilities and limited space for station construction. Each of these challenges are intensely worked on by various players.
In order for the battery swapping to take-off the following are the key points to be considered.
- There needs to be standardised batteries and interfaces without restricting innovation.
- Battery swapping stations should be strategically positioned to provide maximum reach.
- Reduction of the battery swapping service costs by utilising solar/renewable energy or grid electricity using off-peak hours.
- Maintain the quality of battery swapping service for managing battery warranty claims.
- Customers too feel that the battery they are receiving is just as good as the one they are leaving behind.
Need for standardisation in India.
India’s FAME-II (Faster Adoption and Manufacture of Electric Vehicles) scheme is primarily developed with fixed batteries in mind. Standardisation of swappable battery form factor, connector and communication protocol is still under various stages of discussion. The ISO/IEC standards related to battery and swapping stations are also in draft stages. BIS has constituted a committee for drafting the charging station level standard (IS 17017 – Part I).
Lack of standardisation is an important barrier to the rollout of a single harmonised solution. The electric vehicle standards and the battery standards for different companies are different. More importantly, automobile manufacturers generally do not want to adopt one unifying solution as they fight for control. This power struggle and lack of trust makes this standardisation difficult.
There are several policy interventions that are required to make the battery swapping for EV successful. A few of them are listed below.
- EV Tariff is to be made available for swapping infrastructure as well. Currently EV tariff for swapping is not ratified in several states by the state regulatory commissions.
- GST on charging or swapping as a service. Already the commercial electrical tariff in several states are very high and coupled with 18% GST leads to relatively high operating cost for Battery Swapping Stations (BSS). A GST reduction on charging or swapping as service to 5% GST will reduce this burden.
- One size fits all will restrict different consumer segments and use cases. Hence it is recommended to keep it flexible so that the ample scope of innovation can be exploited.
- Support for upgrading the grid infrastructure. LT connections up to 200kW are available only in limited states. DISCOM to provide support in upgrading the grid infrastructure or provide some viability gap funding.
- Allow demand aggregation for availing open access for the BSS.
- Currently under the FAME-II scheme, vehicle OEM is the main anchor and takes the ownership for product liability including batteries. Need policy intervention on how the ownership and liability will be handled when it comes to battery as a service or battery energy operators.
- From consumer viewpoint, there is a need for interoperability or standardisation of the battery across various vehicle OEMs and battery manufacturers.
The battery swapping as a service or battery energy operator is typically compared to the gas cylinder service in India or to the service provided by mobile operators. The mobile handset (EV) is different from the mobile service provider (Battery as a Service) and the same model might work in the case of battery swapping for EV.
It is clear that standardization is key and also recognizing that this might be the way forward for faster adoption especially for some segments like last mile delivery operators. Having said that, the market is still nascent and we should not restrict the innovation that can happen across pack dimensions, connectors and communication protocols so that there is ample…