Why Is My Tesla Only Charging at 16 Amps

If your Tesla is only charging at 16 amps, it’s likely due to a setting, circuit limitation, or environmental factor. This guide breaks down the top reasons—from charge limits to outlet issues—and how to fix them for faster, safer charging.

Key Takeaways

• Charge limit settings: Your Tesla may be set to 16 amps in the charging menu—check and adjust it for faster charging.
• Circuit capacity: Older homes or shared circuits may not support higher amperage, limiting charge speed.
• Charging equipment: Using a NEMA 5-15 outlet or low-quality adapter can cap charging at 16 amps.
• Tesla Wall Connector setup: Improper installation or configuration can restrict amperage output.
• Battery and temperature: Cold weather or a nearly full battery can reduce charging speed temporarily.
• Software glitches: Occasionally, a reboot or software update resolves charging rate issues.
• Utility or grid factors: Power fluctuations or time-of-use settings may affect charging behavior.

Why Is My Tesla Only Charging at 16 Amps?

You plug in your Tesla at home, expecting a quick top-up, but the dashboard shows it’s only drawing 16 amps. That’s slower than expected—especially if you’re used to faster charging. Don’t panic. This is a common issue, and in most cases, it’s fixable.

Charging at 16 amps means your car is pulling about 3.8 kW of power (16 amps × 240 volts). While that’s enough to add roughly 10–12 miles of range per hour, it’s on the lower end for home charging. Many Tesla owners expect 32, 40, or even 48 amps, especially with a Wall Connector. So why the slowdown?

The good news? Most causes are simple to identify and resolve. Whether it’s a setting you missed, your electrical setup, or even the weather, we’ll walk you through every possibility. By the end of this guide, you’ll know exactly why your Tesla is only charging at 16 amps—and how to get it back to full speed.

Understanding Tesla Charging Basics

Before diving into fixes, let’s clarify how Tesla charging works. Your car charges using alternating current (AC) from your home’s electrical system. The onboard charger inside the Tesla converts that AC power into direct current (DC) to store in the battery.

The speed of this process depends on two main factors: the amperage (current) and voltage of your power source. Most home charging uses 240 volts, which is standard for dryers, ovens, and EV chargers. Amperage determines how much power flows—higher amps mean faster charging.

For example:
– 16 amps = ~3.8 kW → ~10–12 miles of range per hour
– 32 amps = ~7.7 kW → ~20–25 miles of range per hour
– 48 amps = ~11.5 kW → ~30–35 miles of range per hour

Teslas can accept up to 48 amps on a 60-amp circuit, but only if your home’s electrical system and charging equipment support it. If any part of the chain is limited—like your outlet, breaker, or car settings—the charge rate drops.

How Tesla Manages Charging Speed

Your Tesla doesn’t just take whatever power is available. It communicates with the charging equipment to negotiate a safe and efficient rate. This handshake ensures the car doesn’t overload your circuit or damage the battery.

The car also monitors:
– Battery temperature
– State of charge (SoC)
– Charger type and capability
– User settings

If any of these factors suggest a slower charge is safer, the car will reduce amperage automatically. That’s why understanding your setup is key to diagnosing why your Tesla is only charging at 16 amps.

Common Causes of 16-Amp Charging

Now let’s explore the most frequent reasons your Tesla might be stuck at 16 amps. We’ll go from simple fixes to more complex ones, so you can troubleshoot step by step.

1. Charge Limit Set Too Low in the Car

This is the #1 reason Tesla owners see 16-amp charging—and it’s also the easiest to fix. Your car has a charging amperage setting that you control.

Here’s how to check:
1. Tap the charging icon on your touchscreen.
2. Look for “Charging Amps” or “Current.”
3. If it’s set to 16, that’s your culprit.

You can increase it up to the maximum your circuit supports. For example, if you have a 50-amp breaker, you can safely set it to 40 amps (80% of breaker rating for continuous loads).

Pro Tip: Always leave a 20% buffer. A 50-amp circuit should run at 40 amps max for safety and code compliance.

2. Using a Standard 120V Outlet (NEMA 5-15)

If you’re plugging into a regular wall outlet—the kind you use for lamps or phones—you’re likely using a NEMA 5-15 plug. These outlets deliver 120 volts and typically support up to 12 amps safely.

But Tesla’s Mobile Connector, when used with a 5-15 adapter, often defaults to 16 amps for compatibility. However, since the outlet can’t actually deliver that safely, the car may limit itself to 12–16 amps to avoid tripping the breaker.

Even if it shows 16 amps, the real power output is only about 1.4–1.9 kW—slower than a 240V setup.

Solution: Upgrade to a 240V outlet like NEMA 14-50 or install a Tesla Wall Connector for faster, safer charging.

3. Circuit Overload or Shared Load

Your home’s electrical panel may not have enough capacity to support high-amperage charging—especially if other appliances are running.

For example:
– Running the dishwasher, dryer, and AC while charging
– Using a shared circuit with other high-draw devices

The breaker may trip or the car may reduce amperage to prevent overheating.

How to check:
– Look at your breaker panel. Is the charging circuit labeled?
– Are other large appliances on the same circuit?
– Does the breaker feel warm?

If your charging circuit is 30 amps but you’re only getting 16, the car may be throttling due to perceived instability.

4. Faulty or Incompatible Charging Equipment

Not all adapters and cables are created equal. Using a low-quality or damaged Mobile Connector, adapter, or extension cord can limit charging speed.

For instance:
– A frayed cable may not carry full current
– A NEMA 6-20 adapter might only support 20 amps
– An extension cord not rated for 240V/30A+ can overheat and reduce output

Best practice: Use only Tesla-approved equipment. Avoid long extension cords, and inspect cables regularly for wear.

5. Tesla Wall Connector Configuration Issues

If you have a Wall Connector but it’s only delivering 16 amps, the issue might be in the setup.

The Wall Connector uses a dip switch or app-based configuration to set max amperage. If it’s set to 16 amps, that’s what your car will receive—even if your circuit can handle more.

How to fix:
1. Open the Wall Connector app or access the device menu.
2. Check the “Max Current” setting.
3. Adjust it to match your breaker (e.g., 40 amps for a 50-amp breaker).

Also, ensure the Wall Connector is properly grounded and installed by a licensed electrician. Poor installation can cause the car to limit charging for safety.

Environmental and Battery Factors

Sometimes, the reason your Tesla is only charging at 16 amps isn’t electrical—it’s environmental or battery-related.

Cold Weather and Battery Temperature

Tesla batteries charge slower in cold weather. When the battery is below ~40°F (4°C), the car may reduce charging speed to protect the cells.

This is normal and temporary. The car uses waste heat from the motor or a battery heater (on newer models) to warm the pack before fast charging.

What you can do:
– Precondition your car while plugged in (use the Tesla app)
– Park in a garage if possible
– Allow extra time for charging in winter

Once the battery warms up, charging speed should increase.

High State of Charge (SoC)

As your battery fills up, charging naturally slows down. This is called the “taper.”

For example:
– At 20% SoC: charging at 48 amps
– At 80% SoC: drops to 20–30 amps
– At 90%+ SoC: may drop to 16 amps or lower

This protects the battery from overcharging and extends its lifespan.

Tip: If you’re only charging to 80–90%, you’ll rarely see the full 48-amp rate. That’s by design.

Battery Health and Age

Older batteries or those with reduced capacity may charge more slowly. While Tesla batteries are durable, degradation over time can affect performance.

If your car is 5+ years old and you notice consistently slow charging, consider a service check. Tesla can run diagnostics to assess battery health.

Software and Settings That Affect Charging

Your Tesla’s software plays a big role in charging behavior. Sometimes, a simple settings tweak or update can resolve the issue.

Scheduled Charging and Departure Times

If you’ve set a “Departure Time” in the charging menu, the car may delay or slow charging to finish just in time.

For example:
– You set departure for 7:00 AM
– The car calculates it only needs 16 amps to reach your target by then

This is smart, but it can be confusing if you expect faster charging.

How to check:
1. Go to Controls > Charging
2. Look for “Scheduled Charging” or “Departure Time”
3. Disable or adjust if not needed

Time-Based Energy Rates (Utility Settings)

Some utilities offer lower electricity rates during off-peak hours (e.g., midnight to 6 AM). If your Tesla is set to charge only during these times, it may start slowly and ramp up later.

Check your energy provider’s app or Tesla’s energy settings to see if this is active.

Software Glitches and Reboots

Occasionally, a software bug can cause charging issues. A simple reboot often fixes it.

How to reboot your Tesla:
– Model S/X: Hold both scroll wheels until the screen turns off
– Model 3/Y: Hold both steering wheel buttons until the screen restarts

After reboot, unplug and reconnect the charger. Charging speed should normalize.

Firmware Updates

Tesla regularly releases updates that improve charging efficiency and compatibility. If your car hasn’t updated in months, it might be missing optimizations.

Check for updates in Controls > Software > Check for Updates.

Electrical Setup and Home Wiring

Your home’s electrical system is the foundation of fast charging. If it’s not up to par, no amount of tweaking will help.

Breaker and Circuit Rating

Every charging setup needs a dedicated circuit. The breaker size determines max amperage:
– 20-amp breaker → max 16 amps
– 30-amp breaker → max 24 amps
– 50-amp breaker → max 40 amps
– 60-amp breaker → max 48 amps

If your breaker is 20 amps, your car will never charge above 16 amps—even if you set it higher.

Solution: Upgrade your breaker and wiring if you want faster charging. Consult a licensed electrician.

Wire Gauge and Distance

Thin wires or long cable runs can cause voltage drop, reducing effective power.

For 40–48 amp charging, use:
– 6 AWG copper wire for runs under 50 feet
– 4 AWG for longer distances

Using 8 AWG or smaller can limit performance and create fire risks.

Grounding and Safety

Proper grounding is critical. If the circuit isn’t grounded correctly, the car may reduce charging speed or refuse to charge at all.

Signs of grounding issues:
– Charger flashes red
– Car shows “charging interrupted”
– Inconsistent amperage

An electrician can test and fix grounding problems.

How to Diagnose and Fix 16-Amp Charging

Now that you know the causes, here’s a step-by-step troubleshooting guide.

Step 1: Check the Charging Amps Setting

– Go to the charging screen
– Tap “Charging Amps”
– Increase to the max your circuit supports (e.g., 40 amps for 50-amp breaker)

Step 2: Verify Your Outlet and Equipment

– Are you using a 240V outlet (NEMA 14-50, 6-50, etc.)?
– Is the Mobile Connector or Wall Connector in good condition?
– Are you using Tesla-approved adapters?

Step 3: Inspect Your Electrical Panel

– Is the charging circuit dedicated?
– What’s the breaker size?
– Are other appliances running on the same circuit?

Step 4: Monitor Environmental Conditions

– Is it cold outside?
– Is the battery warm?
– What’s the current state of charge?

Step 5: Reboot and Update

– Reboot the car
– Check for software updates
– Reset charging settings if needed

Step 6: Consult a Professional

If none of the above work, it’s time to call an electrician or Tesla Service. There may be a hidden wiring issue or equipment fault.

When to Call Tesla Service

Most 16-amp charging issues are user-fixable. But if you’ve tried everything and still see slow charging, it could be a hardware problem.

Signs you need professional help:
– Charging stops randomly
– Error messages like “charging fault” or “reduced power”
– Inconsistent amperage even on a known-good circuit
– Burning smell or warm outlets

Tesla Service can run diagnostics on the onboard charger, battery, and charging port. They’ll also check for recalls or known issues.

Tips for Faster, Safer Home Charging

Once you’ve resolved the 16-amp issue, here’s how to keep charging fast and reliable.

Install a Tesla Wall Connector

The Wall Connector is the gold standard for home charging. It supports up to 48 amps, works with all Tesla models, and includes features like:
– Over-the-air updates
– Load sharing (for multiple EVs)
– App-based monitoring

It’s a worthwhile investment if you plan to keep your Tesla long-term.

Use the Tesla App to Monitor Charging

The app shows real-time amperage, energy added, and charging speed. Use it to confirm your fixes are working.

Schedule Charging for Off-Peak Hours

Charge during low-rate periods to save money. The car will adjust speed automatically.

Keep Your Battery Between 20% and 80%

Avoid frequent full charges. This reduces taper and extends battery life.

Regular Maintenance Checks

Inspect cables, outlets, and the charging port every few months. Clean dust and debris.

Conclusion

If your Tesla is only charging at 16 amps, don’t stress—it’s usually a simple fix. Start by checking your charging settings, then evaluate your electrical setup and equipment. Environmental factors like cold weather or high battery charge can also play a role.

In most cases, adjusting the amperage setting, upgrading to a 240V outlet, or installing a Wall Connector will solve the problem. And if all else fails, a reboot or professional inspection can get you back on track.

Remember, slower charging isn’t always bad. It can protect your battery and home electrical system. But when you need speed, knowing how to unlock it makes all the difference.

With the right setup and knowledge, you can enjoy fast, reliable charging—every time you plug in.

Frequently Asked Questions

Why is my Tesla charging at 16 amps on a 50-amp circuit?

This usually means the charging amperage is set too low in the car. Go to the charging screen and increase it to 40 amps (80% of 50 amps for safety). Also, check that your Wall Connector or Mobile Connector is configured correctly.

Can I charge my Tesla faster than 16 amps on a regular outlet?

No. A standard 120V outlet (NEMA 5-15) can only safely deliver about 12–16 amps. For faster charging, you need a 240V outlet like NEMA 14-50 or a Tesla Wall Connector.

Is it bad to charge my Tesla at 16 amps?

Not at all. Charging at 16 amps is safe and fine for overnight charging. It may even be gentler on the battery. The issue is speed—16 amps adds only 10–12 miles per hour, which may not be enough for daily needs.

Why does my Tesla charge slower in winter?

Cold temperatures reduce battery efficiency. The car slows charging to protect the battery until it warms up. Preconditioning while plugged in helps speed up the process.

How do I increase charging amps on my Tesla?

Tap the charging icon on the touchscreen, then adjust the “Charging Amps” slider. Make sure your electrical circuit supports the higher amperage before increasing it.

Should I upgrade to a Tesla Wall Connector?

If you charge at home regularly, yes. The Wall Connector supports up to 48 amps, offers faster charging, and includes smart features like load sharing and app control. It’s a great long-term investment.