Can Your Electrical Panel Handle an EV Charger?

Before any EV charger goes in, one question decides everything else: does your panel actually have the capacity? Here's how to think through it.

Why this matters more than people expect

Most household appliances cycle on and off — a dryer runs for 40 minutes, a kettle for two. An EV charger is different. Once it starts, it pulls a steady, continuous load for hours at a time, often overnight. That sustained draw is exactly why panel capacity is the deciding factor in whether an installation is safe and code-compliant, not an afterthought to sort out later.

Add a charger to a panel that's already running close to its limit, and the risks aren't hypothetical: nuisance breaker trips, overheating, and in worse cases, a genuine fire hazard. This is why a proper assessment always comes before a quote, not after.

What panel size actually means for you

Most GTA homes fall into one of three categories:

• 60A service — common in homes built before the 1960s. Almost always needs a full upgrade before EV charging is possible.
• 100A service — typical in mid-century homes. Sometimes enough for a Level 2 charger with smart load management; often still needs an upgrade depending on the home's other electrical demands.
• 200A service — standard in newer builds or homes that have already been upgraded. Usually has the headroom for a dedicated EV charging circuit without further work.

Panel size alone doesn't give you the answer, though — it's a starting point, not a verdict.

Level 1 vs. Level 2: how much load are we actually talking about

A Level 1 charger runs on a standard 120V outlet and draws roughly 12-16A — slow, but sometimes usable on existing wiring. A Level 2 charger runs on 240V and draws anywhere from 30-50A continuously, which is a meaningfully different demand on your panel. Nearly every homeowner who wants charging that actually keeps up with daily driving ends up choosing Level 2, which is exactly why the load question matters so much.

What a proper load calculation actually checks

This isn't a guess or a rule of thumb — it's a calculation, and it's required under Ontario's Electrical Safety Code before a Level 2 install proceeds. A licensed electrician looks at:

• Your home's square footage and general lighting load
• Existing fixed loads — HVAC, water heating, major appliances
• Your actual current usage under normal conditions
• The additional continuous draw the charger would add

The result tells you one of three things: your panel is fine as-is, a load management system can make it work, or a panel upgrade is the right call.

Signs your panel might not be ready

• The breaker panel is fully occupied, with no open slots for a new circuit
• Breakers trip during normal, everyday household use
• You still have an old fuse panel instead of modern breakers
• Your home has aluminum or knob-and-tube wiring
• You're on 60A or 100A service and already running a lot of appliances

Can load management avoid a full upgrade?

Sometimes, yes. A load management system watches your home's real-time electrical usage and automatically slows charging speed when other appliances are drawing heavily, keeping total demand within what your panel can safely handle. It's not a fit for every home — whether it works depends entirely on the load calculation, not a general rule of thumb — but where it applies, it can save homeowners the cost of a full panel upgrade.

Permits aren't optional

Every panel upgrade and EV charger installation in Ontario requires an ESA permit and inspection. This isn't paperwork for its own sake — it's what confirms the work meets code, that grounding and bonding are done correctly, and it's what your home insurance and any future buyer will want to see on file. ON Energy handles the full permit and inspection process as a standard part of every job, not an add-on.

Frequently asked

What panel size do I need for a Level 2 charger?
200A service is generally the safest bet without extra work, though 100A panels can sometimes work with load management. The only accurate answer comes from a load calculation.

Can a 100A panel support a Level 2 EV charger?
It depends entirely on what else is drawing from that panel. Some can, many need an upgrade — we confirm which applies to your home during the assessment.

Do I need a dedicated circuit for my charger?
Yes. Sharing a circuit with other appliances is both a code violation and a real safety risk for continuous-load equipment like an EV charger.

ON Energy is a licensed and insured electrical contractor (ECRA/ESA #7011912) serving homeowners across the Greater Toronto Area, with every panel upgrade and EV charger install backed by a 3-year warranty.