How to Avoid EV Charger High Temperatures

Imagine seeing smoke rising from one of your primary chargers.

It’s every fleet manager's worst nightmare. Especially if it happens in the middle of a busy charging period.

If you’re lucky it will be an outdoor charger, rather than an indoor one, reducing risk to human life. 

Thankfully, EV charger fires are rare. 

But when they do happen, the damage to infrastructure and disruption to operations can be severe. That’s why you need to take steps to avoid overheating at all costs. 

The question is – what causes the extreme high temperatures that leads to charger fire and how can you avoid them?

Why Do Fires Occur?

It would be nice if you could narrow EV charger high temperature down to one thing. Unfortunately, that’s not the case. There are numerous potential causes of high charger temperatures.

• Cooling Issues: Like fans on a desktop computer, EV chargers need systems to help them cool down from the heat generated while charging. If you look at the back of an EV charger, you’ll usually see large fans. Sometimes these fans get blocked by fallen leaves or other debris, causing the charger components to overheat.
• Faulty Components: Defective components, such as faulty capacitors, can cause malfunctions that lead to overheating. The problem can increase over time as the faulty component deteriorates more.
• Overloading: Chargers may be pushed beyond their limits if it’s paired with an EV that’s too powerful. Make sure to ensure compatibility with correct EV identification and charging authorization methods.
• Poor Installation: Substandard installation or improperly connected wiring may cause a build up of electrical resistance. Resistance generates heat, which can become dangerous over time.
• Software or Firmware Issues: Glitches or bugs in the charger's software or firmware may put pressure on the internal mechanisms. For example, a firmware glitch may cause the charger to run non-stop cycles and overheat.
• Lack of Maintenance: Severe overheating can occur if regular maintenance isn’t carried out. This includes physical cleaning to remove dust and dirt and visual inspections to spot cracks, loose connections, and broken cables. Functional tests on elements such as the ground fault circuit interrupter should be undertaken.

How Often Should You Take Preventative Measures?

Fortunately, overheated chargers that lead to smoke or fire, are not very common. 

Similar to an internal combustion engine vehicle, such as a bus or truck, catching fire, it is an edge case. This means, in most cases, a charging site will never suffer damages caused by overheated chargers

So why is it important to track these things and implement preventative measures?

Think of your personal insurance for your apartment or house. How often do you face broken pipes that flood your entire property? 

Hopefully never in your lifetime! 

That doesn’t stop most people from taking out insurance. Also, modern buildings or appliances come with flooding detection systems built-in. For the same reasons, companies with EV fleets need to implement emergency tools to prevent and detect overheated chargers.  In some cases, insurance companies insist that companies have precautionary measures in place. While the likelihood of a fire is small, the financial impact is potentially huge. It can ruin your business.

If fleet operators plan to scale up their charging sites, a detection and prevention system is a good idea and it eases the concerns of insurance providers. 

Charging locations with very little space (where vehicles are charging right next to each other or together in a garage) are more prone to overheating than large outdoor charging locations. So if this describes your EV fleet, then make sure to take extra care.

How To Detect Overheated EV Chargers

Detecting and responding to overheating, especially in large-scale fleet operations, requires leveraging advanced technology to secure the site and assets. While no system offers a 100% guarantee, field-tested tools like AI-powered charging management software can automatically identify high-temperature and overheating issues. Our AI-powered charging management software automatically identifies high temperature and overheating issues and triggers automated actions. These actions include stopping all active chargers and preventing anyone from starting a new session. This functionality is supported by most OCPP chargers, though some brands may require a firmware upgrade for this essential emergency stop feature.

Download the Latest OCPP Report

How To Stop Charger From Overheating

Preventing high temperatures involves a proactive and systematic approach focused on maintenance, compatible equipment, and environment. Core steps include conducting regular maintenance to ensure the charger's cooling mechanisms are functioning, and inspecting cables and connectors for damage or loose connections, which can create dangerous electrical resistance. It is also crucial to use compatible and properly rated equipment to avoid overloading the charger and to ensure proper installation.

As EV fleet locations rapidly scale, the demand for sophisticated, real-time detection and prevention functionality is growing to mitigate potentially severe financial and operational risks. If you are interested in seeing a demo of this critical function, please reach out today.

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