Ask any driver what the most important thing about their car or truck is, and the majority would likely say it is the ability to get from point A to point B safely. That is, after all, the main function of a vehicle.
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No car owner wants to find their vehicle is not up to the task when they are. An empty tank of gas will not get them to that crucial client meeting or their kid’s soccer tournament on time.
While electric vehicles (EV) depend on a fuel source different than conventional combustion engine automobiles, that does not sway an owner’s expectation of their vehicle - or fleet of vehicles - for immediate, on-demand transportation.
With the rapid growth of EVs on today’s market in full swing, keeping them fully charged is a key concern. Despite ongoing progress in battery technology, there is still a general impression that EV batteries will run out of juice at the most inconvenient time possible – leaving drivers stranded far away from a charging station.
Furthermore, gas-powered vehicle owners are accustomed to refueling taking only a few minutes. How can charging an electric vehicle ever achieve such levels of speed and convenience?
Paired with longer-lasting power banks, rapid-charging EV technology can alleviate these concerns, making electric vehicles a workable alternative to traditional vehicles driven by fossil fuels.
Yet, developing rapid-charging technology and a complete charging station infrastructure are still a long way from helping potential EV consumers overcome worries about lost time spent charging their batteries.
To those seeking a seamless transition to driving an electric vehicle, actual results matter. Electric vehicle sensors are vital for making charging almost as quick as fueling up at a gas station.
Fast Charging and its Potential Impacts on EV Battery Health
A key element that was absent in the early days of electric vehicle development was the new rapid-charging technology that is now leading the way for the ongoing electrification of transportation.
While rapid-charging systems make the transition to electric vehicles more workable, they require proper monitoring for usage.
The main consequence of fast charging is heat, particularly when converting electrical current from AC to DC. Heat is the worst enemy of an electric vehicle battery pack.
EV batteries of any size have been developed to optimally function within a range of 15-45 °C. Exposure to high temperatures beyond that range may have catastrophic effects on an EV battery’s health:
- Ability to hold a charge: Overheating can dramatically impede a battery’s ability to stay charged, and conversely, extreme cold ambient temperatures can also damage batteries during the charging cycle, causing the formation of dendrites.
- Charging capacity: Exposing EV battery packs to high temperatures reduces their capacity. With a reduced amount of lithium present, there is less to charge.
- Useful life: Rechargeable batteries of all sizes - from AAA to those powering an airplane - are designed to last a few thousand charge cycles. Excessive heat damage can significantly reduce a battery’s usefulness by several years.
- Safety: Overheated EV battery’s start to decompose, initiating thermal runaway. This is a potentially catastrophic chain reaction that may start a fire.
Three Places Electric Vehicle Sensors are Necessary to Monitor Fast Charging
Making sure that rapid EV charging is both safe and efficient starts and stops with sensor technology. High-speed charging cycles require fast-response sensors – principally, vehicle temperature sensors.
Without real-time monitoring systems that activate and maintain those ideal temperatures, the risk of heat damage to an EV’s components dramatically increases.
There are three places in an electric vehicle where temperature sensors are crucial for rapid charging:
- Charge handle connection point
- Thermal management system
- Inside the battery pack
Charge Handle Connection Point
Placing temperature sensors at the point of connection on the charging port and the charging handle is crucial.
To charge at high-speeds, numerous electrons need to quickly pass from the EV service equipment to the vehicle battery. This high current produces heat. High temperatures within the charging port may signify a poor connection between the charging handle and the EV’s contacts.
From the perspective of efficiency, a poor connection means the vehicle is not optimally charging. Additionally, high temperatures from an EV rapid charge connector are also a sign the charger is overexerted by the power demand or that it is beginning to malfunction.
The Thermal Management System
The overheating of an EV’s thermal management system is an instant sign that it is not functioning as designed and its components are running hot, such as:
- Cooling plates
- Coolant fluids
- Dielectric oils
- Heat exchangers
Excessive temperatures may also be a signal that the EV cooling system is being overworked by excessive heat from the parts that they are expected to cool.
Inside the Battery Pack
Quite possibly the worst place for overheating, an EV’s battery pack should be stabilized within the temperature range of 15-45 °C to maintain its integrity and safety. Lithium-ion cells still charge well at temperatures up to 60 oC, but they can experience damage if they exceed those temperatures, even by a little, when charging.
When in-pack temperatures are outside these ranges, at best, the vehicle may initiate safe mode and shut down. At worst, the process of thermal runaway may start.
An overheating battery is one of the major indicators that something is not quite right with the vehicle’s charging or thermal management systems or the battery itself is defective.
To preserve the battery’s long-term functionality and safety, prompt cooling is a necessity.
The Future of EV Rapid Charging
The development of EV rapid-charging technology is not even close to the finishing line.
With current rapid-charging technology, it takes approximately 30 minutes to charge an EV's battery to 80%. However, engineers are still trying to develop a way to fully charge an EV as quickly as filling up an ICE vehicle’s empty gas tank - a process that usually takes less than 10 minutes.
The desire for ultra-fast electric vehicle charging is not driven entirely by a longing for convenience. Ground transit companies and those with fleets of large vehicles (semis and buses) are all but demanding ultra-fast charging. These companies want their vehicles mobile within a matter of minutes.
In other words, due to larger vehicles having much bigger battery packs, they take much longer to charge. Yet, longer charging time represents lost productivity and income.
Fast-response sensors that monitor heat throughout an EV are critical to putting vehicles back in service faster and preventing battery degradation or damage.
Electric Vehicle Sensors and Rapid-Charging Systems: A Necessary Pairing
Though electrification is driving one of the most significant transitions in the history of transportation, vehicle owners and operators still have particular expectations and demands for functionality. Shifting consumer attitudes is made possible by rapid-charging technology as it meets a major concern head-on.
Electric vehicle sensors are the unsung hero of rapid EV charging.
Integrating the Right Sensors for Fast Charging in an EV Design
Speak with one an Amphenol engineer about the electric vehicle sensors on offer today.
This information has been sourced, reviewed and adapted from materials provided by Amphenol Advanced Sensors.
For more information on this source, please visit Amphenol Advanced Sensors.