The concept of a removable battery for an electric car is not a new idea, but it is one that is highly sought after. It appears that one company is closer than others to create a working concept for a removable battery for electric cars, and this company is called tank two. They have developed small, egg-shaped cell batteries that reside in an onboard storage tank.
This is one of the more interesting ideas for a removable electric car battery on the cell level. Other concepts are focused on removing the entire battery pack and not the cell itself. The entire removal of the battery pack has raised concerns over the physical storage of a complete battery pack, the time involved, and safety of the consumer. All of this makes the idea of removable egg-shaped battery cells so interesting for electric cars.
Why an egg-shaped battery cell?
The main reason that the egg-shape, or ellipsoid shape, is used for the battery cell is to reduce the dead space in a battery pack, or in this case a storage tank. The battery cells have multiple connection points with no positive or negative connections. It is estimated that there are 11 to 12 possible connection points between cells. These cells require an onboard chip that decides how to complete the circuit between the other batteries.
One of the big differences is that egg-shaped batteries are smart, or rather have smart cells. The CEO and founder of Tank Two, Bert Holtappelsn, stated during an interview that the smart cells reconfigure the routing every 12 seconds. This is quite different from standard batteries that have hard-wired connection routings between batteries.
One of the main drawbacks of regular batteries is that when a cell is compromised or aged, this will affect all of the connected battery cells. In particular, the effect that this has on the other battery cells is a decreased power output to match the weakest cell.
These cells also perform another function: monitoring and determining which cells are more alike in terms of power and capacity. Talk Two has reported that this will drastically improve the efficiency of battery cells through the management of cells throughout their lives and how they connect to each other.
How are the smart cells stored and transferred to an electric car?
As stated earlier, smart cell batteries have to be housed in a specialized tank on board an electric vehicle. One of the biggest questions is how to transfer the cells out of the vehicle once they are depleted. The current plan is to pump out the smart cells with pneumatic or air to a large storage tank. Current details on this are very basic. The idea is to pump the empty smart cell batteries to the top of the storage tank and refill the electric vehicle tank with fully charged batteries at the bottom of the storage tank.
How long will take to change out depleted battery cells for charged cells?
Tank Two estimates that a complete transfer cycle will take about three minutes from the start of pumping out the empty battery cells to a full of charge battery cells. This is compared to the DC fast charging of a complete battery pack which is estimated to be between 15 and 20 minutes to 80 percent of a full charge.
Is it safe for an average driver to refill their electric vehicle?
This is one of the biggest hesitations that removable battery packs face. Will they be safe enough for the average consumer to use at a charging station or refill station? The safest refilling option, or charge in the case for electric vehicles, is performed while recharging at a charging station. This is due to the safety protocols in the charging handles that will not allow power to flow until a proper connection with the onboard charger is verified. This is not removable so it can be done in a more controlled manner.
With regards to other refillable methods, one of the most dangerous is refueling gasoline-powered vehicles. There is nothing stopping a driver from spilling the combustible and flammable liquid on their vehicle, the ground, or themselves for that matter. There is always a risk of hazardous fumes if you stand too close to the gas tank when refueling, as well.
Of all the refueling or recharging methods, this, in my opinion, will be the safest for consumers. As the battery cells are controlled with a microchip, the connections are no longer present since the management system controlling them is shut down. This makes them safe to handle and transfers into the storage tanks for mass recharging.
Can I use these smart cells in my electric vehicle?
Electric vehicles and battery conferences are intended for automotive companies to find the latest and upcoming technologies. Unfortunately, this means that the average consumer may have to wait a few years to see this technology coming to fruition. In order for a consumer to see this in action, one or more automotive company needs to embrace the technology and the infrastructure for the refueling stations will have to be created.
In the above-noted interview, Bert mentioned that the overall price of battery cells will equate to cost savings compared to the current lithium batteries on the market. This takes into account the additional microchip cost, as they take advantage of the Consumer Electronics Industry Mass production cost efficiency. He does not directly come out and say this, but I interpret that the cost per volume is better when looking at to the egg-shaped batteries compared to the cylindrical shape of lithium batteries. Reducing the air gap between stacked batteries removes unused space and becomes a higher battery density as an end result.
As for the pneumatic pumping of the smart battery cells, this is not an outlandish concept. This technology already exists and merely has to be adapted to this application. It will not take as much time as one might think since this is commonly used in industrial applications. It will, therefore, have to be changed into a commercial application to accept payments.
How much will it cost to pump these cells in my EV?
It will be interesting to see how much it will cost to refill an entire battery tank. There has been no talk regarding the end cost to the consumer or electric vehicle driver to refill the battery cells. There are few models that could be used as a peruse model or on a flat monthly charge model. I would not be surprised if the fee turned out to be a flat monthly charge as most monthly driving habits are consistent. Within a flat monthly charge, there could end up being multiple tiers as well in order to provide a wider range between the low use daily driver and the Long Haul driver.
The cost to refill at the pumps is all speculation at this point. I’m interested to hear what your thoughts are on the possible price structure that smart cell batteries could have.
Let me know your thoughts about these pumpable egg-shaped batteries. Are they a good idea or bad idea? What are your concerns?