Master Electrical Contractor in Haverhill, MA – Moore Electric Inc

Buying an EV is the easy part. Figuring out whether your electrical panel can actually handle a charger? That's where most Southern NH and Seacoast homeowners get stuck.

The short answer: most homes need at least a 200-amp panel to safely run a Level 2 EV charger alongside everything else in the house. But "most homes" doesn't mean yours. Here's how to figure out what you actually need.

Do I Need to Upgrade My Panel for an EV Charger?

It depends on two things: what your panel is rated for right now, and how much of that capacity you're already using.

A Level 2 charger (the kind that fully charges overnight, which is what you want) pulls 30 to 50 amps on a dedicated 240-volt circuit. If your home has a 100-amp panel, that charger alone could eat up a third to half of your total capacity before you even turn on the AC or dryer.

Here's the quick rule we use on site:

If you're not sure what you have, look at the main breaker at the top of your panel. The number stamped on it is your total capacity.

How to Check If Your Panel Has Room

Before we install a charger, we run a load calculation on your home. This isn't guesswork. It's a code requirement (NEC Article 220), and it accounts for everything pulling power in your house:

• HVAC system
• Electric dryer and range
• Water heater
• Well pump (common in Plaistow, Hampstead, and surrounding towns)
• Existing circuits and lighting

We add the EV charger's draw to that total. If the sum exceeds 80% of your panel's rated capacity, an upgrade is required before installation. The 80% rule exists because the NEC doesn't allow you to load a panel to its full rated capacity on continuous circuits like EV chargers.

What Size Breaker Does an EV Charger Need?

The breaker size depends on which charger you're installing:

Charger Level	Breaker Size	Charge Speed
Level 1 (standard 120V outlet)	15-20 amp	4-5 miles of range per hour
Level 2 (240V dedicated circuit)	40-50 amp	25-30 miles of range per hour
Hardwired high-output	60 amp	35+ miles of range per hour

NEC requires a dedicated circuit for EV charging. That means no other outlets or appliances share that breaker. It's not optional; it's code.

We install Level 2 chargers in the majority of homes we work on. It's the sweet spot between speed and cost, and it handles overnight charging for any EV on the market right now.

When a Panel Upgrade Makes Sense

Many homes in Southern NH were built with 100-amp or even 60-amp panels. These were sized for a different era, before heat pumps, induction ranges, and EV chargers became part of daily life. If your home falls into any of these categories, you're likely looking at a panel upgrade before the charger goes in:

• Built before 1990 with the original panel
• Breakers trip regularly when running multiple appliances
• You're planning other high-draw additions (heat pump, hot tub, workshop)
• Your panel has a Federal Pacific or Zinsco label (known safety concerns)

The upgrade itself typically takes a day. We pull the permit, coordinate with the utility if a service upgrade is needed, and handle inspection. Your power is off for a few hours while we swap the panel, then everything comes back online with proper capacity for today and whatever you add next.

What About a Subpanel Instead of a Full Upgrade?

Sometimes a subpanel is the smarter move. If your main panel has available amperage but sits in the basement while your garage is on the other side of the house, running a subpanel to the garage keeps the wire run short and the installation clean.

A subpanel fed from your main panel gives the EV charger its own dedicated space without rewiring your entire service. We assess which approach makes more sense during the site visit, because the right answer depends on your home's layout, existing wiring, and what else you might want to add down the road.

NEC Requirements That Apply to Your Installation

The National Electrical Code governs every EV charger installation. Three sections matter most for homeowners:

• Article 625 covers EV charging systems specifically: circuit sizing, disconnect requirements, and ventilation for indoor installations.
• Article 240 sets overcurrent protection rules. Your breaker must be rated at 125% of the charger's continuous load (that's why a 40-amp charger needs a 50-amp breaker).
• Article 220 dictates how load calculations are performed to determine if your panel can handle the addition.

The 2023 NEC update added provisions for load management devices, which let some homes avoid a full panel upgrade by dynamically sharing capacity between the charger and other circuits. We can walk you through whether that applies to your situation.

Permits and Inspections in NH

New Hampshire requires an electrical permit for EV charger installations. That means the work gets inspected, which protects you. We handle the permit application and scheduling so you don't have to coordinate between the town and the utility. Licensed in NH (#14511), MA (#22825), and ME (#MS60023064).

What Does This Cost?

Every home is different, and the final number depends on whether you need just the charger circuit or a full panel upgrade to support it. We put together a detailed breakdown on our cost of electrical services page that covers panel upgrades, EV charger installations, and the factors that move the price up or down.

We also offer financing through Wisetack. You can prequalify online without affecting your credit score. Most homeowners spread the cost over 12 to 24 months.

Ready to Find Out What Your Home Needs?

The fastest way to get a real answer is a site visit. We look at your current panel, run the load calculation, and tell you exactly what's needed for safe, code-compliant EV charging. No guessing, no generic advice.

Brenden Moore has been doing this work for over 25 years, and he's directly involved in every project we take on. This isn't a franchise crew showing up. It's a Master Electrician who built his reputation one job at a time.

Related reading: EV charger installation services | Electrical panel upgrades