Why Is My EV Charging So Slow at Home?

You plug in your electric vehicle overnight, expecting a full battery in the morning—only to wake up and find it’s barely charged. Slow charging at home is one of the most common frustrations EV owners face. The good news is that in most cases, the issue is easy to diagnose and fix.

In this post, we’ll break down the most common reasons EV charging is slow at home and what you can do to speed it up.

How Fast Should EV Charging Be?

Before jumping into problems, it helps to set expectations. EV charging speed depends on three things:

• Charger type

  • Level 1 (120V outlet) → 2–5 miles of range per hour.

  • Level 2 (240V outlet) → 15–30 miles of range per hour.

• Your car’s onboard charger (the car itself controls how fast it accepts power).

• Your electrical setup (breaker size, outlet quality, dedicated vs. shared circuit).

If you’re using a regular household outlet, “slow” is normal. But if your Level 2 charger is crawling, there’s likely a problem.

Common Reasons EV Charging Is Slow at Home (and Fixes)

1. You’re Using a Regular 120V Outlet

Level 1 charging is naturally slow. If you’re plugging into a standard wall outlet, you may only gain 40–50 miles of range overnight.

Fix: Install a Level 2 (240V) charger for 5–10x faster charging.

2. Undersized Breaker or Circuit

EV chargers need a dedicated circuit with the right breaker size. If your circuit is undersized, the charger may limit output to prevent tripping the breaker—slowing charging speed.

Fix: Upgrade to a correctly sized 240V breaker and dedicated circuit.

3. Shared Circuit Load

If your EV shares a circuit with other appliances (dryer, A/C, etc.), charging speed may drop because the available power is split.

Fix: Move your charger to a dedicated line.

4. Charger Settings Are Limiting Current

Some EV chargers (and EVs themselves) allow you to set a maximum amperage for charging. If it’s set too low, charging will be slower than expected.

Fix: Check both your charger app and in-car settings for adjustable limits.

5. Your Car’s Onboard Charger Capacity

Every EV has an onboard charger that determines the maximum charging speed it can handle. For example, if your EV’s onboard charger only accepts 7 kW, plugging into a 10 kW charger won’t speed things up.

Fix: Unfortunately, this is a vehicle limitation—you can’t upgrade the onboard charger.

6. Voltage Drop from Long or Thin Wiring

Long runs of wiring, undersized cables, or the use of extension cords can reduce charging efficiency and slow things down.

Fix: Use a properly rated circuit, avoid extension cords, and keep wiring runs as short as possible.

7. Cold Weather

In freezing temperatures, your EV may use power to heat the battery before charging efficiently. This can dramatically slow charging speeds.

Fix: Precondition your car’s battery (most EVs have this option in the app) before plugging in during cold weather.

8. Charger Malfunction or Wear

If your charger is old, damaged, or low quality, it may not consistently deliver power.

Fix: Test with another charger or cable. If charging is faster, your equipment may need replacement.

When to Call a Professional

If you’ve ruled out the obvious and charging is still slower than expected, it may be an electrical issue. Signs you should call an electrician or EV charging specialist:

• Breaker trips during charging.

• Charging speed is much lower than your car’s rated capacity.

• Your charger or outlet feels hot to the touch.

How to Ensure the Fastest Charging at Home

• Install a dedicated 240V outlet sized properly for your EV.

• Upgrade to a Level 2 charger for 5–10x faster speeds.

• Keep your charger close to your breaker panel to minimize voltage drop.

• Protect your charger from the elements with proper installation.

Final Thoughts

Slow EV charging at home can be frustrating—but in most cases, the fix is simple. Whether it’s upgrading to a Level 2 charger, adjusting settings, or installing a dedicated circuit, the right solution can make overnight charging easy and reliable.

At Frisco EV Charger Installation, we specialize in fast, safe, and reliable EV charger setups. We’ll help you get the most out of your home charging so you can hit the road every morning with confidence.

👉 If you need help with EV charger installation in Dallas, Plano or the surrounding area, contact us today for a free consultation and discover how much faster your EV can charge at home.