This Home EV Charger Was Quietly Destroying Itself: What Went Wrong on Bainbridge Island

A little smoke in the garage. That is how this story starts.

A homeowner on Bainbridge Island, Washington did his homework before finishing the last stretch of his home EV charger circuit himself. He bought high quality connectors. He used a torque wrench. He thought he had done everything right. Then his garage caught fire.

His story is not rare. As more drivers install EV chargers at home, more of them are running into the same kind of problem: a small wiring mistake that seems harmless at first, and then is not. In the newest episode of Recharge Rescue, Tom Moloughney, host of the popular State of Charge YouTube channel, flew out to see the damage firsthand and bring in a certified electrician to fix it for good.

Watch the full story below, then keep reading to see why this is a legitimate risk with DIY projects, and what it takes to get it right the first time.

What Happened in This Garage

A couple of years earlier, a licensed electrician had run an 80-amp circuit from the homeowner’s panel out to a junction box in the garage, in case he ever wanted to add an EV charger later. That part of the job was done correctly.

About eight months before this video, the homeowner picked up a discount from his local utility and finished the job himself. All that was left was a short run, about a foot and a half, connecting that junction box to his new charger. He used 6-gauge wire, which is the right size for the job, and paired it with high quality connectors instead of cheap twist caps. On paper, it looked like a careful, well-researched install.

Then one evening he smelled something electrical in the kitchen and saw smoke drifting out of the garage. The circuit breaker never tripped. When he opened up the junction box, the wiring inside was melted together.

Luckily, the box was metal and fully sealed, which kept the damage contained. It could have gone very differently.

Why This Keeps Happening: EV Circuits Don’t Forgive Small Mistakes

Here’s the part that matters for every homeowner reading this, not just the one in this story: he did not do a bad job. He researched wire gauges. He bought quality parts. He used a torque wrench. And it still failed.

When the certified electrician, Tyler Keyser, a Qmerit Network partner, opened up the box, he found the problem right away. One of the splice connections had not been torqued down tightly enough. Over time, that small gap increased contact resistance, and higher contact resistance caused I²R heating.

According to Devan Maypray, Qmerit’s Technical Support Expert, “On most circuits in your home, a slightly loose connection might never cause a problem. A ceiling fan pulls a few amps for a few hours a week. An EV charger is a different animal entirely. It often runs at 30 to 48 amps continuously for 4 to 10 hours at a stretch, night after night.

That’s frequently more power than everything else in the house is using combined. Any weak point in that circuit is under constant stress, and it significantly increases the likelihood of overheating and failure.

The loose connection created extra contact resistance, which generated heat. As the connection heated up, the metal and terminals degraded and the contact became even poorer. That increased the resistance further, producing even more heat. Over time, this self-accelerating cycle can lead to overheating, melting, or complete failure.”

This is also why the National Electrical Code includes what is often called the 80% rule for continuous loads. A circuit’s wiring and breaker have to be sized so the charger only ever asks for 80% of what the circuit can safely deliver, with real headroom left over.

Getting that math right, and making sure every connection is installed to spec, is exactly the kind of detail a general contractor or a confident DIYer can miss, even with good intentions.

Related Reading: Can a General Contractor Do Electrical Work?

There’s one more detail from this story worth knowing. The homeowner’s circuit breaker never tripped during the fire. Breakers are designed to trip when a circuit pulls more current than it is rated for. They are not designed to sense heat or flame.

In this case, the heat from the failing splice happened to melt through the insulation on a nearby, unused neutral wire, and contact between that wire and the hot wire is what finally shut off the power. It was a lucky break, not a safety feature working as intended.

This Is a Bigger Problem Than One Garage

This homeowner’s story is a clear example, but it reflects a much bigger trend. Electrical issues are already one of the leading causes of home fires in the United States. According to the Electrical Safety Foundation International, home electrical fires cause an estimated 51,000 fires, close to 500 deaths, more than 1,400 injuries, and $1.3 billion in property damage every year.

At the same time, home EV charging is growing fast. The Department of Energy’s National Renewable Energy Laboratory projects that the country will need about 28 million EV charging ports by 2030, and roughly 25.7 million of those, or about 92%, will be private Level 1 and Level 2 chargers installed at single-family homes.

That means millions of new high-power circuits are being added to houses across the country in a short amount of time, often by whoever the homeowner can find first.

A few common mistakes show up again and again in EV charger installations that were not done by an EV-certified electrician:

• Using the wrong wire gauge or type for the charger’s amperage and the length of the run
• Skipping or miscalculating panel capacity, so the circuit is added without confirming the panel can actually support it
• Under-torquing or over-torquing connections, which either leaves a gap for resistance to build or damages the connector itself
• Skipping permits and inspections, which removes a second set of trained eyes from the process
• Choosing a non-compliant outlet or location for a plug-in charger

None of these require carelessness. They require the kind of specific, hands-on EV charging experience that most general electricians, however skilled, simply have not built up yet.

How a Qmerit-Certified Electrician Fixed It the Right Way

Once Tyler and his technician opened up the circuit, they found a second issue: the connector inside the charger itself had also failed from repeated use, so the homeowner ended up with a new charging unit as part of the repair.

Rather than simply patching the same setup, Tyler took the opportunity to improve it. Since the original circuit was actually oversized at 80 amps for a charger that only needed about 48 to 60 amps, he installed a small sub panel at that location instead of another junction box.

From the sub panel, he ran new, correctly rated wire straight to the charger, which eliminated the splice connection entirely. Fewer connections in the circuit means fewer places for something to eventually go wrong.

Maypray adds, “It’s worth noting that the type of wire matters just as much as the wire size. The homeowner’s original 6-gauge NM-B cable (commonly called Romex), may look similar to other electrical cables, but different cable types have different ratings and are designed for different applications. An EV charger is a continuous high-current load, meaning it can pull significant power for several hours at a time.

The replacement wiring was properly selected for the charger’s requirements and installed according to the equipment specifications. Two wires can look nearly identical on the outside while having very different limits based on their construction, insulation, and approval ratings.”

The homeowner’s own reaction says it best: after seeing what a single loose connection could do, he said he would not attempt EV wiring himself again, and would call a Qmerit-certified installer instead.

State of Charge subscribers echoed this sentiment, with video viewers posting the following comments:

• “…I’d definitely hire it out to a EV specialized electricians through Qmerit.” -@andrewt9204
• “We have a ’24 Mach-E and used Ford’s charger installation program, which involved a Qmerit-approved electrician and a permitted installation. The county inspector said it was one of the best installs he’d seen. It’s given us no problems in over a year and a half of use. It wasn’t cheap, but we have peace of mind that the job was done right.” -@noshooz21044
• “Double check, triple check, annual check… use a professional. This is not a place to skimp on.” -@PattyTheGeek

What You Risk by Skipping a Certified Installer

A DIY installation or one handled by an electrician without EV-specific training can lead to more than just a scare in the garage. It can also mean:

• A voided manufacturer or vehicle warranty, since most EV charger makers and automakers require certified installation as a condition of coverage
• Complications with your homeowner’s insurance, since unpermitted or improperly installed electrical work can give an insurer grounds to deny a claim
• A failed inspection, which means paying to redo work that should have been done correctly the first time
• Problems at resale, since unpermitted electrical work tends to surface during home inspections

The short-term savings from a DIY job or a bargain contractor rarely survive contact with these long-term costs. A properly permitted, correctly installed charger is not just safer. It protects the investment you already made in your EV and your home.

Why Qmerit

Qmerit is North America’s largest network of certified EV charger installers, and the installer recommended by State of Charge. Every electrician in the Qmerit network is licensed, insured, and specifically trained in EV charging work, not just general electrical work.

Qmerit’s certified electricians have completed more than 770,000 EV charging station installations and over 86,000 electrical panel upgrades across the United States and Canada.

The process starts with a simple online assessment. Answer a few questions about your home and your electrical panel, and Qmerit matches you with a local certified installer and provides an upfront estimate.

This post features insights from Tom Moloughney, host of State of Charge on YouTube. Qmerit is the recommended EV charger installer for the State of Charge channel.

Related Reading:

• Can You DIY Home EV Charger Installation?
• Do You Need a Permit to Install an EV Charger?
• Find a Licensed Electrician Near You Through America’s Most Trusted Contractor Network