What Size Breaker Do I Need for a Tesla Charger?
Maybe you bought a Tesla Model S, X, or three recently and know you can charge it with a home charger, but do you know what size breaker you will need to use?
Electric cars save on fuel but must be charged with electric power. To control the charging process and protect the car’s charging system from high currents, you will need a suitable circuit breaker installed. The breaker size required will be specific to the car and your charging requirements.
This article explains the difference between the level one and two chargers, tells you what charging options you have, and gives a chart to help you install the right-sized breaker in different arrangements.
Using the supplied level one mobile connector can run on a regular 20 amp breaker, but a full charge will take days. To use a level two charger, you will need at least a 30 amp breaker, and if running on a 240VAC for even quicker charging, then a 50 amp breaker is standard. However, if you use a Tesla Wall Connector with the 240VAC supply, you will need at least a 60 amp breaker.
You will find a chart for different charging options below.
Tesla Chargers
Tesla home chargers usually come in two basic types: level one for trickle charging and level two for quicker charging.
A standard level one charger can be plugged into any power outlet without worrying about the circuit breaker. The normal 12 amps of power delivery are sufficient to charge the car. But an overnight charge will only give you enough for around 40 miles (around 4-5 miles per hour of charging).
If you need more charge than that, you will need to charge in public places or at work, use a level two charger in slow mode, or else arrange for a proper level two charger at home. A slow level two charger can operate on a 30 amp power plug, allowing you to charge at 24 amps. But a level two one will allow you to charge the Tesla for driving it more than 100 miles.
If the level two charger at home suits you better, you will need to make some changes and use a higher size breaker to manage a higher current. I will tell you exactly what you will need to do.
Arranging for a Level Two Charger
Although a level two charger is more efficient than a level one charger in an at-home charging solution, it may require installing a new main service panel if it cannot handle a 50 amps circuit.
The main circuit breaker in homes is usually for managing 100 amps. A level two Tesla charger will require a 200 amp main panel. So if you don’t have that, you will have to upgrade it first to handle more power-intensive appliances. Then, you will have to run a 50 amp (or minimum 40 amps) line to the charging spot, which is the common setup.
If you already have a 200 amp or higher panel, you only need to arrange a 50 amp dedicated circuit (which will allow you to charge at 40 amps and require a six gauge copper cable).
Breakers for Quicker Charging Options
A 240V outlet, without or with a Tesla Wall Connector, can give you even quicker charging options but will require a higher-rated circuit breaker.
If you can arrange a 240V power outlet, you can increase the charging rate significantly compared to a level 1 charger and slow level 2. You will need a 50-60 amp breaker on a dedicated circuit with a thicker 6 gauge cable.
A Tesla Wall Connector is worth getting if you can afford it for more cost-effective yet faster charging. You can use it on any size circuit from 15 to 100 amps, but it is more commonly used in a 220VAC circuit with a minimum 60 amp breaker.
Bottom Line
I’m not saying this particular EVSE, the new Wall Connector with 14-50 Plug, is the one for you. I’m only saying that that after reading this article, you’ll be able to make a more informed charging solution decision for yourself. It really depending upon your requirements, garage layout, and budget. Also have a listen to this podcast segment that explains that your charging losses may be roughly 5-10% less at 48 amps than at 40 amps, so go with the electrician-installed Wall Connector if you can afford to wait for one ordered from Tesla and installed by an electrician, who will likely also have to upgrade your wiring and breakers. If you already have a NEMA-14-50 though, the Wall Connector with 14-50 Plug might be a great choice for you.
The Tesla Model 3 is fast becoming a popular car, and the base are due to become lower this year, which should accelerate sales even further. In the Luxury Vehicle category, it was the best seller in 2018, and it’s the first American car on that list in many years.
Brisk sales also means a lot of first time EV (Electric Vehicle) buyers like me will have an experience much like mine: The car can be ordered and picked up in well under a week now that production has ramped up, but that’s far faster than you can get an electrician to your house. Finding the exact details to tell your electrician was a challenge for me, and I wished a detailed article like this one existed. My family enjoyed over a thousand miles those first 2 weeks, and we sure are glad we live only 4 miles from a Supercharger, which was free for our first months of Supercharging.
Why the urgency in getting a charging solution installed in our garage? Because charging at home at 3 to 4 miles of charge per hour from a regular wall outlet wasn’t exactly cutting it for our multi-hundred, dead-of-winter family road trips during the multi-week wait for an electrician.
Worry not, the Model 3 is a wonderful car. Coupled with a new charger that came out just in time, and I can safely say that things worked out very well for me and my family in the end.
Let me help you navigate the many charging options for the Tesla Model 3, listed at the online Tesla Store here. Note that it’s often not exactly easy to find some or any of these in-stock at local Tesla locations, at least not for me here in CT (Connecticut), with no dealerships state-wide, and zero charger inventory at Tesla Service Center of Milford CT.
Important to get the terminology right, Cleantechnia helps here:
that cable in the trunk known as the Mobile Connector (formerly known as the UMC or Universal Mobile Connector), comes in. The Mobile Connector (MC) allows an owner to charge their Tesla from non-Tesla power sources.
Many Tesla Online Store Choices
Remember, my shopping was for my Tesla Model 3 Long Range Dual Motor, your needs and battery capacity and charge rates will vary, see Tesla’s Wall Connector article for the latest details.
Electrician installs NEMA 14-50 outlet, you plug in.
No electrician? Just plug into a regular outlet using the provided adapter, but you’ll only see a 3-5 mph charge rate.
Gen 2 Mobile Connector Bundle This is the charger the Model 3 comes with since 2018, and should be kept in the car. You can buy another to keep in your garage. The current Gen2 version limits charging speeds to 32 amps, versus the 40 amps the Gen1 units came with. Hard to find a definitive answer why this reduction.
Option #2. 520. 40 amps (37 mph)
Electrician installs NEMA 14-50 outlet, you plug in.
Corded Mobile Connector [Maybe?] I also asked Milford CT Tesla Service if this accessory listed under Model S Charging was safe to use with the Model 3 for long term use, and they were unable to get a definitive answer. Since it has the hard-wired NEMA 14-50 cord, it should get a 40 amp charge rate. But then why isn’t it listed on the list of chargers for the Model 3?
Option #3. 500. 48 amps (44 mph)
Electrician hard-wires Wall Charger for you.
This is also known as the HPWC, High Power Wall Charger.
Silver or Gloss Black Wall Connector, in 8.5′ or 24′ lengths. This pretty much requires an electrician install it, although I realize some DIYers will take this on themselves. I’d rather have my insurance company know my electrician pulled a permit and passed an inspection, should something bad happen some day. Yes, you are paying for that.
While the signaling between Wall Connector sounds good, that would mean you’re assuming both EV cars in your garage someday would both be Teslas, and both would use the same style of charger. There’s also the additional cost in having these signal cables connected to consider, really only needed if you have only one circuit in your garage. I now have enough juice on hand for two.
Tesla Supercharger V3
Since December 2019, Tesla has begun installing the new V3 Superchargers in Europe too. These Tesla stations offer a maximum charge current of up to 250 kW. In addition, the V3 charging stations no longer share the power, so that the entire 250 kW is available exclusively for each charging stall. All vehicles will benefit from the elimination of power-sharing, while only certain models will benefit from the higher charging capacity. Visually there are no differences to the V2 charging stations, only the cable is a little thicker with V3. You can identify V3 Supercharger Locations in the Navigation System of your Tesla.
Ionity is a company that operates a public network of fast charging stations along freeways. Consisting of a joint venture of BMW, Daimler, Ford, Volkswagen and Hyundai, Ionity began building this network in 2017. All charging stations have a CCS plug, which is standard on Model 3 and will be supplied as an adapter for Model S and X from March 2019. Older Model S and X can retrofit the CCS adapter for an additional charge. Ionity charging stations offer a maximum output of 350 kW.
Ionity locations – Image credits: Ionity
Comparison of the maximum charge current according to Tesla model
The following table lists the maximum possible charge current per Tesla model. However, depending on various factors such as temperature, battery state of charge, age of the battery, etc., it may be lower.(Turn the phone to display the entire table or move the table)
1 = since software update 2019.40 (previously limited to 100 kW). 2 = Not clear from which production date 225 kW are possible. 3 = 100 kWh battery from production date 06/2020. 2 = Since software update 2019.20 the previously maximum charging power of 118 kW was reduced.
Reduction of the charge current with frequent DC charging (On Tesla Supercharger and other DC charging stations)
Anyone who charges at a Rapid charging station charges their vehicle with direct current (DC). Very frequent DC charging has a negative effect on the life of a battery. That is why Tesla seems to have introduced a limit that is automatically activated after a certain number of kilowatt hours charged with direct current. Experiences of Tesla drivers in the TMC forum show, as this is the case after 13125 kWh over DC. (DC= charging on Supercharger, Ionity, CHAdeMO or other fast chargers). Affected are Model S and Model X with 75, 90 and 100 kWh battery. details here.
Tesla has limited the maximum charging capacity of the 70 and 85 kWh battery with the software update 2019.20. It is assumed that the battery life is otherwise reduced too much. Even when the battery is cold, the 70/85 kWh batteries charge significantly slower than before.
The Tesla Data Logger
Collect statistics about your trips, power consumption, battery degradation and much more.
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Simplifying the Complex: An Evolution in Vehicle Control Coding
The role of vehicle control in the FSD system is paramount. It enables the car to execute critical operations such as steering, accelerating, or braking based on decisions informed by the surrounding environment. It’s like the final act of an orchestra, where the car translates all the data collected from sensors and AI processing into movement.
Musk’s latest tweet (or X?) suggests a massive leap forward in this respect. He stated that Tesla will drop 300k lines of C control code by ~2 orders of magnitude. In layman’s terms, Tesla plans to significantly simplify the complexity of the vehicle control code. by nearly a hundred times. This suggests a significant evolution in Tesla’s approach to vehicle control, transitioning from traditional coding to more advanced machine learning or neural network approaches.
Training the Tech: Limitations and Future Prospects
Such a simplification doesn’t just mean less code but also signals a massive boost in efficiency and reliability. It’s as if Tesla is cutting out the unnecessary noise in the conversation between the car and its driving environment, enabling a smoother, safer, and more intelligent drive.
Even as Tesla strives towards this vision, Musk, who recently said that v12 of FSD is mind-blowing, acknowledges that progress is not without its bottlenecks. In the same tweet, he remarked, Our progress is currently training compute constrained, not engineer constrained. While this highlights the intensive computational demands of training these sophisticated AI systems, it also subtly nods toward Tesla’s dedication to overcoming these hurdles.
The path to full self-driving is filled with complex challenges, and it’s clear that Tesla is tackling them head-on. With vehicle control being hailed as the final piece of the FSD puzzle, it seems that Tesla may be closer than ever to realizing its goal of a fully autonomous driving future. And as Musk has hinted, the only roadblock is computational resources, which Tesla has repeatedly shown it’s more than capable of overcoming.
Tesla Faces NHTSA Scrutiny Over Reported Steering Failures In Model Y and Model 3
The National Highway Traffic Safety Administration has initiated a preliminary examination into approximately 280,000 recently produced Tesla Model 3 and Model Y vehicles. This significant figure underscores the scale of potential implications. This action follows alarming reports of steering loss and impaired power steering, raising considerable safety concerns.
This investigation has been sparked by 12 grievances lodged by owners of 2023 Tesla Model 3 and Model Y vehicles.
Factors To Consider When Buying A Breaker For A Tesla Charger
Tesla’s chargers are not just regular charging stations. They provide an experience that is unlike anything else in the world.
These chargers are designed to be one of a kind, and when you buy them, you have to understand the factors that will affect your experience with them.
But before installation, you will need a suitable circuit breaker, and there are some factors to consider when buying this.
Electrical Load Capabilities
The electrical load size is an essential thing that matters when charging your Tesla and using a break. This includes the watts, amps, and volts needed when plugging the vehicle into the outlet.
For example, if you used a 240V charger with a 50 amp breaker, this would equal about 12,000 watts.
You need to check these calculations to see if this will provide enough watts to charge your car correctly.
Desired Recharge Rate
The next thing that matters is how quickly you want to be able to charge your car when it is plugged in. You can get a faster charge with a bigger breaker and outlet adapter.
For example, the 120V adapter will charge your car 3 miles per hour. But the 240V adapter will charge the car 30 miles per hour.
With a 50 amp breaker, you would get about 23 miles per hour.
It is obvious which is the better choice. You will need to match the proper breaker size to the 240V adapter.
Electric Service Size
The electrical service size also impacts charging and varies based on the breaker size.
However, you won’t need much from the service to charge a car, and it is not recommended to install a new service for this.
Your existing service can likely handle the electrical load without any issues.
For example, charging your Tesla on a 240V adapter equals a similar load to a stove in the kitchen.
How Many Amps Does A Tesla Home Charger Draw?
The Tesla Home Charger is a device that can charge your Tesla Model 3, Model S, or Model X.
The charger comes with a built-in inverter and AC output. It does not have a DC input and can only be used to power the vehicle.
Tesla’s home chargers are designed to draw as few amps as possible. They have a maximum continuous current of 48 Amps, depending on the size of the breaker.
Below we list the standard circuit breaker sizes used and the equivalent amps these breakers can draw for the charger.
60 Amp Circuit Breaker
The 60 amp breaker is the largest recommended by Tesla, providing an output of 48 amps for charging. This equals about 11.5 kW and works for all four Tesla models.
50 Amp Circuit Breaker
The 50 amp is the most common breaker with a power output of 40 amps and 9.6 kW.
40 Amp Circuit Breaker
The 40 amp breaker has an output of 32 amps and 7.7 kW when running a 240V power adapter.
30 Amp Circuit Breaker
The 30 amp breaker is small but still can charge slowly with 24 amps and 5.7 kW of output.
How Fast Does A 50 Amp Breaker Charge A Tesla?
Tesla has been known to be an innovator in electric vehicles, and the latest product is Tesla’s home charger.
It is designed for those looking for a quick charge for their Tesla vehicles.
It’s important to note that the Tesla home charger does not have a fixed power output, and it will depend on how much power your house is drawing.
When using a 240V outlet on a 50 AMP, you can expect your Tesla Model 3 to charge roughly 30 miles per house.
This would give you a full charge overnight.