Why EV Chargers Run Slowly in Some Homes and What You Can Do About It

Sometimes the car charges overnight without issues, while other times the charging rate drops dramatically or hardly increases at all.

A slow EV charger is not always a sign of a faulty unit. In fact, most slow charging problems come from the home electrical setup, the car settings or the property infrastructure rather than the charger itself. If you are noticing slow EV charging at home in Cheshunt, understanding the cause is the first step towards fixing it.

Let’s look at the most common reasons an EV charger runs slowly and how a professional electrician can resolve them.

Your Home Wiring May Be Restricting Charging Speed

Many homes in Cheshunt still contain older wiring that was never designed to support high demand loads like EV chargers. Even if your property had previous upgrades, the circuit supplying your EV charger may be limited by age, cable type or cable thickness.
When wiring is outdated, the charger detects the limitation and automatically lowers the current to protect the circuit. This is a built in safety feature, but it results in slower charging. In some cases the cable may also be worn, have high resistance or suffer from voltage drop over distance. An electrician can test the wiring and identify whether a dedicated new circuit is needed.

The Earthing System in Your Home May Affect Charging Speed

Modern EV chargers rely on a stable earthing arrangement for safety. If the earth reading is too high or inconsistent, your charger may reduce its speed or pause charging altogether.

Properties in Cheshunt that still rely on older earthing systems often see these issues. A new earth rod or upgraded bonding may be required to keep charging stable and efficient. This is a simple fix for an approved electrician but makes a big difference in reliability.

Shared Circuits Can Lower Charging Performance

If your EV charger is sharing a circuit with other high demand appliances such as electric showers, ovens or tumble dryers, charging speed can drop significantly. Shared circuits are a common cause of slow charging in houses that have not had a true dedicated EV charger circuit installed.

An EV charger should always have its own circuit. This allows it to operate at full capacity without competing for power. If your charger is slowing down at the same time your appliances run, it is a sign you need a dedicated feed.

Your Off Peak Charging Settings May Be Slowing It Down

Many smart chargers and EVs are programmed to use the cheapest tariff available, especially for homeowners in Cheshunt who use flexible night rates. Off peak settings can override normal daytime charging. If the schedule is set incorrectly, the charger may delay power delivery or restrict it without you realising.

It is always a good idea to check your car settings, your charger app and your energy provider’s tariff schedule. A simple adjustment can instantly restore normal charging speed.

Your Home’s Overall Electrical Load May Be Too High

Every property has a limit on how much electricity it can safely handle at once. If you have air conditioning units, heat pumps, electric cookers and multiple appliances running, your EV charger may lower its speed automatically to prevent overloading the supply.

This is called load management. It is designed to protect both your home and the charger. An electrician can calculate your property’s maximum demand and recommend upgrades such as:

• A higher main fuse.
• A new consumer unit.
• Load balancing solutions.
• Smart charging adjustments.

This ensures your EV charger can operate at full speed without risk.

Weather Can Affect Charging Speed More Than You Think

Cold temperatures, especially during Cheshunt winter nights, can slow charging dramatically. EV batteries warm themselves before accepting full power, which reduces the initial charging speed. Hot temperatures can have a similar effect by causing the charger to protect itself from overheating.

While this is normal, improving the installation environment can help. Many homeowners benefit from sheltered outdoor setups or chargers mounted away from direct weather exposure.

When to Ask an Electrician for Help

If your home EV charger in Cheshunt continues to run slowly even after checking your settings, there is likely an electrical cause. An approved EV installer can run tests on the wiring, earthing and load capacity to identify the issue quickly.

Slow charging is frustrating, but it is almost always fixable. A properly installed charger on a dedicated circuit with the right settings should deliver consistent performance every day. If yours does not, it is worth having it checked before the issue becomes a safety risk.

For reliable EV charger testing, upgrades or new installations in Cheshunt, our team is here to help.

📞 Call JJB Electrical on 01992 276121 to book an EV charger check or installation.