Your electrical panel is the hub of your home's power, and a Level 2 charger adds a large, continuous load to it. Whether your panel can support a charger depends on your service size, what else runs in your home and how the panel is set up. This guide explains the main factors so you know what to check before calling an electrician.
Service size and the main breaker
Many US homes have a main service rated at 100, 150 or 200 amps. The main breaker sets the maximum current the house can draw at one time. A larger service leaves more room for an EV charger, but the service rating alone does not tell the whole story.
What uses your capacity
Major loads include electric heating or cooling, electric water heaters, ranges and ovens, clothes dryers and hot tubs. Their combined draw during peak times determines how much capacity remains. Lighting and small appliances use less than most people expect, but they still count toward the total.
A worked example
Suppose a household's typical peak demand is about 70 amps. On a 200-amp service, adding a 40-amp charger brings the peak to about 110 amps, which leaves plenty of room. On a 100-amp service, the same addition would exceed the rating, so a service upgrade or a lower charging setting would be needed.
These numbers are illustrative only. Your electrician performs a load calculation based on your actual equipment and the rules that apply where you live.
Panel space
Even when total capacity is sufficient, the panel must have an open slot for a double-pole breaker and room for the new wiring. An older panel may be full, may be a model that is no longer supported, or may need replacement before a new circuit can be added. A panel upgrade is a larger job, and your electrician can tell you whether it is needed.
Options that reduce the load
Some homeowners choose a lower charging current to keep the total load within their existing service. Another option is a dedicated circuit sized for that lower current. Discuss these options with your electrician before buying a charger, so the equipment matches the capacity you have.
Questions to bring to your electrician
- What is the rating of my main breaker and my service?
- How much of my panel is already in use?
- Are there open slots for a new breaker?
- Does the panel need an upgrade before a charger can be added?
How this applies to EVIQO chargers
EVIQO's 40A (9.6 kW) chargers draw about 40 amps and need a 50-amp circuit. The 48A (11.5 kW) chargers draw about 48 amps and need a 60-amp circuit. Those circuits must fit within your panel's capacity. All five EVIQO chargers, across the J1772 and NACS connector options, use a 240-volt supply and come with a 25 ft cable and a 3-year warranty.