Exponent Energy -- an energy-tech start-up on Monday unveiled the tech behind its 15-minute rapid charging solution for the EV industry. Exponent showcased its proprietary energy stack - battery pack (e^pack), charging station (e^pump) and charging connector (e^plug) that together unlock a 15-minute rapid charge, and long battery life – all done on regular LFP cells for the first time in history.
Rapid charging kills range anxiety and the need for expensive, oversised battery packs. With this unique two-sided approach, EVs powered by exponent will be 30 per cent more affordable, made possible by an optimised battery capacity (30 per cent smaller), and five year financing (powered by 3000 cycle life warranty). Additionally, 15-minute rapid charging reduces EV charging cost by 33 per cent.
Exponent’s energy stack addresses two key problems that, for decades, prevented rapid charging on LFP cells – Lithium plating and Extreme heat.
Tackling Lithium Plating To Prevent Significant Cell Degradation
When charging a cell, Li-ions flow from the cathode to the anode and get absorbed. The faster you charge, the more ions flow, leading to crowding around the anode. If left unchecked, this crowding leads to lithium plating, resulting in significant cell degradation. Exponent solves this through a combination of their Battery Management System (10 times more accurate than industry standard), Virtual Cell Model and Dynamic Charging Algorithms. This allows them to proactively sense Lithium crowding in real-time and ensure each cell is rapid charged without significant degradation.
This approach was validated by an independent testing laboratory - TUV India (TUV Nord Group, Germany) that found only 13 per cent degradation after 3000 charging cycles of 15-minute rapid charging.
Off-Board Thermal Management For Rapid Charging In Any Ambient Temperature
15-minute rapid charging generates a ton of heat. 256 times more than the industry average of 4 hour charging. If this heat isn’t extracted, the battery pack would overheat and switch off. Furthermore, in India, the ambient temperature is 40°C or higher and Li-ion cells have a far lower thermal sweet spot of 25-35°C. To solve this, we need advanced HVAC systems, which are both bulky & expensive. Additionally, this level of heat is generated only when one rapid charges an EV and not driving it.
Therefore, Exponent has built an advanced HVAC system that’s “off-boarded” from the vehicle to its e^pump. While charging, the e^pump transfers refrigerated water through the e^plug to cool every Li-ion cell in the e^pack. This ensures the e^pack’s temperature doesn’t exceed 35°C in any ambient temperature condition. Furthermore, with the expensive system “off-boarded”, EVs powered by Exponent are both affordable and lightweight.
Speaking on the occasion, Arun Vinayak, CEO and Co-founder, Exponent Energy said, “At Exponent, we’re building the future of energy that combines cutting-edge engineering with real world economics, and our off-board thermal management system is a testament to that belief. For everyone to go electric, consumers need EVs that charge faster, last longer, and cost lesser. Our unique two-sided approach to 15-minute rapid charging makes EVs last 3 times longer and cost 30 per cent less than conventional EVs. We’re excited to scale this across India starting with Delhi-NCR, Mumbai, Hyderabad, Chennai and Ahmedabad!”
In the past year, Exponent partnered with Altigreen, resulting in the successful launch of the first EV powered by exponent – the neEV Tez. Looking ahead, Exponent aims to deepen their presence in the three-wheeler cargo and passenger vehicle market and also explore new vehicle categories.