The Revolution is the first race car with our fast charging technology. Right now, charging within 12 minutes is very impressive, but we want this to be even faster. InMotion is eager to really put Electric Refueling into practice; make charging as fast and convenient as refueling. We are doing this by making our current battery pack charge even faster. This first iteration consists of a 57.6 kWh battery pack which we can charge within 12 minutes. In the course of 2021, we will further develop the battery pack to reduce the charging time to an even more impressive time.
What are we currently working on?
One of our proudest achievements is the development of the battery box of the Revolution. The battery pack itself consists of 30 battery modules provided by Microvast, each containing 12 cells, yielding a total voltage of 750V. While driving the car, the modules are discharged. When the driver presses the gas pedal, the modules are discharged and heat is generated. However, this heat is not something we want in our battery pack because high temperatures can damage the cells. Therefore, InMotion has developed its own cooling system, consisting of 2 separate loops. This enables us to manage the temperature within the batteries, which results in better functionalities and lower charging times.
The current cooling system: inside loop
The cooling system that is currently included in the battery pack of the revolution is meant to take the heat out of the pack and take it to the outside of the car. This happens in 2 loops: one inside the battery box and one outside the battery box.
Between the modules
of the battery pack are cold plates. The plates contain channels, through which
flows a liquid. This liquid is a mixture of water and other cooling fluids.
When the liquid flows through the channels, the heat will transfer from the
module to the liquid. This means that the modules cool down and the liquid
flowing past the modules warms up. The warm liquids passed through so-called
chillers: the chillers extract the heat from the liquid and transfer the heat
out of the battery box, to the outside loop. The liquid will cool down again
and can be reused to cool down the modules.
The current cooling system: outside loop
The second loop consists of a refrigerant system (like an air-conditioning system), which is used to extract heat from the first loop and transfer it to the environment. The advantage of such a refrigerant system is that it allows us to keep the batteries at their optimal temperature, even if the outside temperature is higher. The outside loop receives the heat from the chillers. This heat once again needs to be cooled down. This is done through the radiator, just like with a regular car. The radiator cools the hot liquid using the cooler air that comes in through the vehicle’s grille. The liquid flows through narrow channels inside the rad, exposing it to a large surface area so the heat can dissipate as quickly as possible. If sufficient air isn’t coming in through the grille, such as when the vehicle is idling, a fan behind the radiator pulls air through it.
The goal of InMotion ’21-‘22 - the next generation battery pack
The current cooling system allows us to charge from 20% to 80% in 12 minutes. In order to bring the charging time down even further, we are currently developing our own battery modules. Now, the battery box is cooled on module level. However, we want our next-generation battery pack to be cooled at cell level. We are currently testing different types of cooling solutions for cell-level cooling to create a new pack of cells and modules, to eventually deploy the next generation battery pack in the Revolution. The result will be more efficient cooling, and therefore improve the endurance and charging times of the battery pack.