Why is my Tesla Charging Slow at Supercharger? Is this a Software or Hardware Issue?


Having a charge using a supercharger for your Tesla should be an exciting event.  Nevertheless, many owners are complaining that the charge is slow at a supercharger and there is zero indication as to why this might be happening according to the manual for Tesla.  This includes model x and even model 3.  Could it be a software update or a hardware problem that is not allowing the charge to flow fast into the Tesla at these supposedly fast charging stations?

Why is my Tesla charging so slow at a supercharger station? A Tesla may experience slower charging at supercharger stations if the vehicle has already performed numerous fast charges at supercharger stations.  Frequent supercharges will cause chemical and physical changes to the battery pack making it necessary to slow down the charge at superchargers.  It is software with the supercharger equipment that causes this slower charge rate to happen. The vehicles are still operating as before, this charge in charging is to safeguard the battery pack. 

There are many owners that only charge at supercharger stations because they are free to some owners.  They are able to stop at a restaurant, supercharge for an hour or so, which allows them to carry on with their day carefree because they have a battery pack that is well charged.  Many owners are outraged at Tesla for limiting their supercharger charge rate. It is something that was not advertised.  Engineers have coding that limits several features in the Tesla that the typical owner would not realize are in play; however, charging limitations is one such feature that is frustrating many owners.

Click here to view my pick for a charger for home use that is level 2, made by Juicebox that can be purchased online at Amazon.

Tesla states that this is only happening to about 1 percent of the owners and that it is only adding about 5 minutes to the time of charge.  I have read that people are stating that their typical charge times are greatly increasing.

Is Tesla Throttling the Superchargers?

The concept of throttling speeds of charging is similar to the throttling that some internet companies have been accused of during the 90s If you were downloading large files from sharing sites, it was possible that your speed of download would be decreased.  At that time, if everyone was charging at the same time large files, a bottleneck was created.  Throttling at superchargers is a new concept, but there are experts that believe that this is happening.

Cnet stated in an article that at some Tesla charging centers, throttling was happening.  Tesla was claiming that this decrease in speed was because of the heavy use of specific owners at superchargers and the reduction in charging speed was to protect the battery packs.  Nevertheless, reports from owners in different locations in the States is greatly a pattern.  The pattern is that in busy locations, the cars were slowing down during a supercharge to a snail’s pace.

People feel that this is a way to discourage owners from sitting for long periods of time at the supercharger.  It provides more owners with the chance to charge well enough to travel throughout the day.

Tesla has admitted that in rare situations in areas with a huge number of Teslas that this measure is in place so that the throughput can be increased greatly; close to 35 percent of an increase.

I feel that this restriction makes sense since in most cases a charge of 80 percent would be sufficient.  Nevertheless, for owners that are not able to deal well with distance anxiety for electric cars, this could cause a lot of stress. There are Tesla owners that have stated that they need a higher level of charge so that they can reach the next supercharger station during a long trip.  Their schedule would be ruined if they were required to charge at a level 2 charging station at a roadside diner.

Tesla engineers have stated that they are dealing with this very type of situation.  They have added code that takes into consideration the planned trip information that was inputted so that the charge will be high enough to reach the next supercharger outlet.  However, not all owners are savvy enough to input the stop points on their trips to take into account the nearest charger stations that have superchargers.  These owners will have to deal with the possibility of spending extra time at a charge station because they will only be able to reach the 80 percent charge level.

Owners yet again are frustrated.  They are feeling as if Tesla was hiding this information from the common owner because it only affected a small portion of the owners, the ones that like to plan long trips in an electric car.  Nevertheless, long trips in a new Tesla should be a pleasant change for people, it should not become a source of anxiety.

The lesson to be learned is to study well the manuals so that you will not be surprised when particular scenarios in a Tesla arise that affect charge levels and the ability to travel easily between charging stations, fast or not.

Here is a video showing whether it is easy or not to charge a Tesla Model Y at a Supercharger station:

Is it Supposed to be Slower to Charge at a Supercharger in Cold Weather?

It does take longer to charge during cold weather even at a supercharger since some of the charge is being used to heat up the battery.  If the battery cells are cold, they will not allow as much of the current to flow into them.  Surprisingly, there is no way to manual control the heating of the cells so that the rest of the charging session will go well.  It is something that is software-driven by a Tesla.

What is interesting is that if your battery is at a lower charge level during cold weather, it will actually charge faster.  For instance, if the level is at 10 percent, the supercharging will happen faster than if you were to start at 25 percent of a charge.  At 25 percent, the battery pack gets warmed up to the level where throttling will occur.  In other words, it is hotted up too fast.  The rate of warming of the cells is more gradual it seems at 10 percent, which does not let the throttling aspect kick in.

Besides trying to charge while at a lower level, to begin with, some owners are trying to warm up the cell before starting the charging.  It seems as if you charge while the battery pack is cold, the charge rate will be slower during the process.  It does not seem to ramp up once the cells are warm.  So, this might be a way of ensuring that the supercharging rate is higher throughout the charging.

For those of us in a cold climate, try to drive around an hour or so before using a supercharger.  This might eliminate the need for the charging to be throttled due to software code in your Tesla.

Even though there seems to be a lot of concerns in the overall charging time due to cold weather, you need to realize that the extra time is not outrageous.  Also, even as your Tesla ages, it will still start quickly in cold weather.  Sometimes with older gas vehicles, it takes time to leave home on a cold morning.

I will highlight the speed of charging at a supercharger station that can be expectedhow f for the average Tesla owner, not just focussing on cold weather conditions.

How Fast Should a Supercharging Be Charging a Tesla?

In order to know whether or not your charging ability at a supercharger is slow or not, you need to what is normal charging speed for the average Tesla at one of these stations.

I decided to focus on the Model Y, at the time of the writing of this article, it was the newest model.  Of course, I am expecting that it would have the best technology for charging at a supercharger.

Apparently, you can obtain:

Full charge for 240 miles within 50 minutes.

Click here to view a charger for home by Tesla Motors that works with Model x, Model 3, and even Model Y

This was indicated by Tesla.

There are a few things that you should watch out for when charging at a supercharger station that will affect your supercharger changing times:

  1. Make sure to verify the power outage of the charging area.  this can be done by looking at an interactive map of the closest supercharger stations.  I did not realize that there could be a difference in the power outage, so keep this in mind when planning your trips.
  2. Sometimes in remote areas, the chargers do not have dedicated power, they share the power.  If the location is not in a larger city, be prepared to wait a bit longer to charge at a supercharger station if there are many cars being charged at the same time.
  3. The charger will communicate with your Tesla.  If it realizes that you have enough of charge to reach a supercharger area based on your trip information, it might slow down the charge.  If your battery has a low charge, it will charge faster to reach a level that allows you to easily reach the next charging location.
  4. If you are in an urban area, you will not have to worry if the location is busy. Each car will be able to charge at 72 kW of power since dedicated power is being allocated to each station.
  5. If it is extremely cold on a particular day, charging will take longer in most cases since it takes energy to warm up the battery cells.  The cells need to reach a certain temperature before they can be charged quickly.
  6. For those owners that enjoyed low charging times, over time their charging times could increase. The battery quality changes due to its age and its usage.  Nevertheless, apparently, the charging time will only be slightly affected.  You may see an increase in charging time of just a few minutes.

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