Optimizing Fast Charging with Electric Vehicle Sensors

Ask any driver what’s the most important feature of their car or truck, and most will likely say the ability to safely get from point A to point B. That is, after all, the primary function of a vehicle. 

The last thing any car owner wants is to find their vehicle isn’t ready when they are. An empty tank of gas won’t get them to that important client meeting or their kid’s soccer tournament. 

While electric vehicles (EV) use a different fuel source than their traditional combustion engine counterparts, that doesn’t change an owner’s expectation of their vehicle -- or fleet of vehicles -- for immediate, on-demand transportation. 

With the rapid expansion of EVs on the market already underway, keeping them fueled -- or fully charged -- is a major concern. Despite advances in battery technology, there’s still a perception that electric vehicles will run out of juice at the worst possible time -- stranded miles away from a charging station. What’s more, gas-powered vehicle owners are used to refueling taking only a few minutes. How can charging an electric vehicle ever approach that speed and convenience? 

Coupled with longer-lasting power banks, fast-charging EV technology meets these concerns -- and makes electric vehicles a viable alternative to those powered by fossil fuels. 

Even still, fast-charging technology and an accompanying infrastructure of charging stations aren’t enough to help potential EV consumers overcome worries about time lost re-energizing. To those looking for a seamless transition to driving an electric vehicle, actual results matter. electric vehicle sensors are necessary for making charging nearly as quick as fueling up at a gas station.

Fast charging & its potential impacts on ev battery health

A missing puzzle piece in the early days of electric vehicle development, new fast-charging technology is responsible in part for the ongoing electrification of transportation. 

While fast-charging systems make the conversion to electric vehicles more practical, they can’t be used without proper monitoring.

Why? The primary byproduct of fast charging is heat, especially when converting electrical current from AC to DC. Heat is an electric vehicle battery pack’s worst enemy. EV batteries of any size are designed to perform within a range of 15-45°C. Exposure to high temperatures outside of that range has harmful effects on an EV battery’s health, impacting its:

• Ability to hold a charge: Overheating can severely hamper a battery’s ability to stay charged and extremely cold ambient temperatures can also harm batteries when charging through the formation of dendrites

• Charging capacity: Exposure to high temperatures reduces an EV battery pack’s capacity. With less lithium present, there’s less to charge.   

• Useful life: Rechargeable batteries of any size -- from AAA to those powering an airplane -- are designed to last a few thousand charge cycles. Damage from excessive heat can reduce a battery’s usefulness by several years. 

• Safety: Overheated EV battery cells begin to decompose, triggering thermal runaway -- a chain reaction that may start a fire.  

  
  

3 places electric vehicle sensors are necessary to monitor fast charging

Ensuring that high-speed EV charging is safe and efficient starts and stops with sensor technology. Fast charging requires fast-response sensors -- primarily vehicle temperature sensors. 

Without real-time monitoring that triggers the systems that maintain ideal temperatures, the risk of heat damage to an EV’s components increases drastically.  

There are three places in an electric vehicle where temperature sensors are a must for fast charging:

• Charge handle connection point

• Thermal management system

• Inside the battery pack

  
  

1. charge handle connection point

Temperature sensors are a must in two places at the point of connection: the charging port and the charging handle. 

To charge quickly, many electrons need to pass from the EV service equipment to the vehicle battery quickly. This high current generates heat. High temperatures within the charging port may indicate there’s a poor connection between the charging handle and the EV’s contacts. From an efficiency standpoint, a poor connection means the vehicle isn’t charging as quickly as it should be. In addition, high temperatures from an EV quick charger’s connector are also a sign the charger is overtaxed by the power demand, or that it’s starting to malfunction.

2. the thermal management system 

Overheating within an EV’s thermal management system is an immediate signal that it’s not working as intended and its components are running hot, such as:

• Heat exchangers

• Cooling plates 

• Coolant fluids

• Refrigerants 

• Dielectric oils 

Excessive temperatures are also a sign that the EV cooling system is being overwhelmed by excessive heat from the parts they’re supposed to be cooling.

3. inside the battery pack

Arguably the worst place for overheating, an EV’s battery pack must be kept within the range of  15-45°C to preserve its integrity and safety. Lithium-ion cells charge well when they are between 45 and 60C, but can suffer damage slightly above those temperatures when charging. When in-pack temperatures go beyond that range, the vehicle may go into safe mode and shut down, or worse, start the process of thermal runaway. 

A battery overheating is one of the last indicators that something isn’t right with the vehicle’s charging or thermal management systems, or the battery itself is malfunctioning.

To maintain the battery’s long-term functionality and safety, immediate cooling is a necessity. 

the future of ev fast charging 

The development of fast-charging technology is far from finished. With existing fast-charging technology, it takes around 30 minutes to re-energize an EV's battery to 80%. However, engineers are still working to make fully charging an EV as fast as filling up an ICE vehicle’s empty gas tank -- a process that typically takes less than 10 minutes.

The demands for ultra-fast electric vehicle charging aren’t entirely being driven by the desire for convenience. Ground transit companies and those with fleets of large vehicles (semis and buses) are all but demanding ultra-fast charging, which could have their vehicles mobile within a matter of minutes.  

Put simply, larger vehicles have battery packs several times bigger than those used in electric cars. They take longer to charge. But time spent charging represents lost productivity and income. 

Fast-response sensors that monitor heat throughout an EV are critical to:

• Putting vehicles back in service faster

• Preventing battery degradation or damage  

  
  

electric vehicle sensors & fast-charging systems: a necessary pairing

Though electrification is one of the biggest transitions in the history of transportation, vehicle owners and operators still have a certain level of expectation for functionality. Fast-charging technology is making this shift possible as it meets a major concern head-on. Electric vehicle sensors are the unsung hero in making EV charging as uneventful as filling up a gas tank. 

Integrate the right sensors for fast charging in your ev design，Speak with AMPHENOL SENSORS about the electric vehicle sensors they offer today.