The answer to 'why is my EV charger dimming lights' is that your EV charger may be drawing too much power from your home's electrical system, causing a voltage drop that dims the lights. This is a common issue when installing a high-powered EV charger, especially in older homes with limited electrical capacity.
Some common causes include: the EV charger exceeding the electrical panel's amperage rating, a wiring issue causing voltage drops, or other large appliances running at the same time as the charger. Symptoms include dimming, flickering, or pulsing lights when the charger is in use.