EV Charger Surge Protection – Our Simple Guide

With electric vehicles representing a significant financial investment, it’s important to understand how surge protection works and why it matters. Power surges, whether caused by lightning, grid switching, or sudden outages, can damage both your charger’s electronics and your vehicle’s battery management system.

In this blog, we’ll explain how EV charger surge protection works, the devices used, and the key considerations for different installations. We’ll also cover the relevant regulations and standards that surge protection devices must meet to keep you, your charger, and your vehicle safe.

What Is EV Charger Surge Protection?

What do we mean by EV charger surge protection? Will in simple terms, it refers to the use of specialist devices designed to shield your charging equipment, and your vehicle, from sudden, damaging spikes in voltage. These power surges, can occur in an instant and send excess electrical energy through wires that can potentially destroy the sensitive electronics inside your charger or causing lasting damage to your EV’s battery management system.

For EV chargers, protection is typically installed at two points, at the consumer unit (or the fuse box) to catch large surges at the source and at the point of use. They are always close to the charger itself, to handle any residual voltage that gets through. Together, these two layers provide robust, reliable protection for your charger and vehicle.

Given how much we rely on our electric vehicle’s day to day, ensuring your charging setup is properly protected is a simple but important step that’s easy to overlook, and one that could save you from a very costly repair bill at the least.

Risks of Having No Surge Protection

While power surges severe enough to cause serious damage are relatively uncommon, the consequences of being caught without protection can be significant, affecting not just your vehicle and charger, but potentially your wider electrical installation. Here are the key risks you could face without surge protection in place:

• Permanent damage to your EV charger: a single power surge can destroy the internal electronics of your charger, requiring a costly repair or full replacement
• Damage to your vehicle’s battery management system: surges can travel through the charger directly into your EV, potentially causing irreversible damage to one of the most expensive components in the vehicle
• Voided manufacturer warranty: many EV and charger manufacturers will not honour warranty claims where surge damage has occurred and no protection was in place
• Increased fire risk: uncontrolled voltage spikes can cause overheating in your charger or wiring, raising the risk of electrical fire
• Unexpected downtime: a damaged charger means no charging until it’s repaired or replaced, leaving you without a reliable way to power your vehicle
• Costly repair bills: between the charger, wiring, and potential vehicle damage, the financial impact of a single surge event can run into thousands of pounds
• Reduced charger lifespan: even smaller, repeated surges that don’t cause immediate damage can degrade your charger’s components over time, shortening its working life

As you can see, the risks of going without EV charger protection are not worth taking, particularly given the significant investment an electric vehicle represents. The good news is that serious surge events are relatively rare, and with the right protection in place during installation, the chances of experiencing any of the issues above are greatly reduced.

How Do EV Surge Protectors Work?

The specialist devices that ensure EV charger surge protection are known as Surge protection devices (SPDs). They work by detecting excess voltage and diverting the surplus energy safely to earth before it can reach your charger or your vehicle. Think of it as a barrier between the power supply and your equipment, absorbing or redirecting dangerous spikes without interrupting your charge.

However, the way surge protection is applied can vary depending on the environment and scale of the installation. A home charger setup has very different requirements to a charger located at businesses, charger for fleet depots, a public charging hub, or an older charger being brought up to current standards. Here is how surge protection works across a range of different settings:

Applications for Surge Protection Devices

Commercial Uses

In commercial settings, the electrical infrastructure is larger and more complex, meaning the potential impact of a surge is greater. SPDs are typically installed at the main distribution board to protect the entire site, with additional point-of-use protection at individual charging units. Given the higher voltages and currents involved, Type 1 or Type 2 SPDs are commonly specified depending on the site’s exposure to lightning and grid disturbances.

Uses for Business Ev Charging

For businesses operating EV charging as part of their facilities, whether for staff, fleet vehicles, or customers, protecting that infrastructure is essential. SPDs are integrated into the dedicated charging circuits, often alongside energy management systems. Any downtime caused by surge damage can disrupt operations and result in significant repair costs, making robust protection a sound business decision.

Public Charging

Public charging points are particularly exposed to surge risk due to their outdoor locations and continuous operation. SPDs must be robust, weather-resistant, and capable of handling the demands of high-traffic, round-the-clock use. Protection is typically built into the charging unit itself as well as the upstream supply infrastructure, ensuring both the equipment and users are kept safe.

Upgrading Old Chargers

Older EV chargers were often installed before surge protection became standard practice. When upgrading or retrofitting an existing charger, it is an ideal opportunity to bring the installation up to current regulations by adding an SPD at the consumer unit or point of use. This is particularly important where the existing wiring and electrical setup may already be showing signs of age.

Additional Applications

Surge protection is also relevant in a number of other settings, including residential apartment blocks with shared charging facilities, car parks and hospitality venues offering guest charging. In each case, the principle remains the same, protecting the equipment, the building’s electrical installation, and the vehicles being charged from the damage.

What Do The Regulations Say Around Surge Protection?

Surge protection for EV chargers isn’t just good practice; it is increasingly shaped by regulation and industry standards. Understanding what the rules say can help ensure your installation is compliant, safe, and covered in the event of a claim.

The key standard governing surge protection in the UK is BS 7671, the IET Wiring Regulations (18th Edition). Under these regulations, a risk assessment must be carried out for every electrical installation to determine whether surge protection is required. For the majority of EV charger installations, domestic or commercial, this assessment will conclude that an SPD is either required or strongly recommended.

For commercial and public charging installations, additional British Standards apply to the charging equipment itself, meaning both the units and the supporting electrical infrastructure must meet the required level of protection.

Need Help with EV Charging Protection?

If you are looking for a reliable surge protection solution for your commercial EV charging setup, VPG can help. We provide full EV charger protection services for a range of business applications, ensuring your charging equipment and vehicles are safeguarded at all times.

To find out more, visit our EV charger protection services page or get in touch with a member of our team today.

 

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