Tesla Battery Management System BMS Calibration

Tesla Battery Management System BMS Calibration
Tesla Battery Management System BMS Calibration

When you buy an electric vehicle, the charging protocol is essential. Sometimes, due to improper charging habits, the battery of Tesla can have calibration problems. In turn, these specific calibration problems can result in battery degradation, which could show up even if this is applicable to the new Tesla. But Why is Tesla Battery Management System (BMS) Calibration?

The Tesla Battery Management System BMS calibration is a proprietary process carried out by Tesla to ensure accurate monitoring and control of the battery’s performance. It involves adjusting parameters within the BMS to optimize battery efficiency, longevity, and overall performance. Calibration is crucial for maintaining the battery’s health and maximizing its lifespan.

Calibration ProcessEnsure accurate monitoring and control of the battery
PurposeEnsure accurate monitoring and control of battery
Optimize efficiency, longevity, and performance
ImportanceCrucial for battery health and maximizing lifespan

In the previous extensive test, the Tesla Model 3 battery degraded only two percent after fifty thousand miles of utilization. But this is different all time. Some owners have also experienced a sudden range degradation just after driving the vehicle for a few thousand miles.

Detail About The Tesla Battery Management System BMS Calibration

Owners sometimes comment about an indicated battery range not being what this was, that charging prevents short of a hundred percent even while set to a hundred percent, or that they have heard about rebalancing the particular batteries. It is all managed by a battery management system, and also this is generally reasoned by one of 2 problems.

  1. The BMS also has been unable to control the calibration of this & the accuracy of this has drifted 
  2. The battery has become unbalanced as an individual cell voltage can easily drift.

Still this relatively unusual to have the faulty & the guide we are giving below. And also provides you with some methods to restore a few of the lost indicated range.

But this is worth nothing, as the range displayed on a screen is unlikely ever to show the read provided by the Tesla while charged to a hundred percent. There are a couple of causes for this, and the temperature will also not be optimal; there also will be small losses in the capacity. For a few countries where the vehicle is rated utilizing the WLTP standards, the vehicle will differ as the costs utilized are generally based on EPA standards which are more pessimistic.

This is one of the most frequent inquiries from new customers whose brand-new car does not display the range the spec sheet indicated, even though this is completely normal and accurate. Remember that the battery stores energy, not miles, and that the mileage estimate is based on a conversion factor used by the vehicle, which assumes a rate of 4 miles per kilowatt-hour.

What Do You Know About Calibration And Cell Balancing?

For the BMS to properly understand the status of a battery, this requires maintaining the calibration of this. To do so, this requires a variety of stable readings across a range of states of charge.

To get a stable reading, a battery must be left for various hours without being utilized or charged, generally without running sentry mode. If the vehicle is generally recharged straight after the journey, then the vehicle will not deliver the stable reading until the charging has been completed.

Consequently, the vehicle will have some, if any, readings at the lower of charge. As a BMS extrapolates through these readings, this has, if there are some low downs, will begin to be very much cautious & assume the dropping capacity. If readings are available at the lower states of charge, a BMS will also be able to know where both hundred to zero percent are more appropriate. This battery can be balanced and fine, but this BMS requires the data to report this properly.

Cell balancing is trying to get all these individual battery cells to the same charge level. While this battery pack becomes unbalanced, an BMS has to try & work out what the real capacity is when protecting individual battery cells, that is, keeping those all within their working range.

Each of these issues has a slightly different solution, and both may be required if you believe your automobile has lost some of its anticipated range.

Calibration Of The Tesla Battery Management System

The battery is taken care of by the Tesla Battery Management System (BMS). In addition to controlling charging, it calculates the amount of energy drawn from the battery, determining how far the car can be driven with that energy.

It accomplishes this by utilizing a self-adapting algorithm that continuously updates itself depending on the information gathered from reliable battery readings. It requires accurate measurements collected at various charge states to maintain accurate calibration. Even while it seems simple, it is more difficult than you might think if the car is constantly being driven or charged.

In addition to giving the battery time to settle down and the various battery groups time to stabilize, the car should recalibrate itself using these readings and rectify any under the reading of the possible range.

Eventually, this battery will prevent and prevent on current. Be mindful that if you have the heating on, the vehicle will still be taking current, but not for charging the battery.

If the vehicle would not allow a hundred percent to be set, it can be the calibration problem & address which aspect first.

Charging Speed For The Tesla Model S

Charger levelCharging time
NEMA 5-153 miles of range per hour
NEMA 14-508 to 12 hours
Wall connector7 to 8 hours
Supercharger25 to 30 minutes

Balance of cells

If the automobile is left alone, the battery cells will, to a certain extent, balance themselves out, although there may still be some residual imbalance. The battery gains from a 100% charge to remedy this.

  1. Plug the car in to charge, preferably at an AC charging point. You can also use a rapid charger, although that may cause it to be unavailable to other users for a while. Leave the automobile to charge with the charge limit set to 100%.
  2. The automobile may claim to have finished charging when it reaches what appears to be 100%, but it is drawing current. When the automobile says no more energy is being added to the battery, keep charging. Once the car has reached 100%, this can take some time (around an hour). It’s okay if the charge rate drops to less than 10A. Allow the automobile to complete its task.

How To Calibrate Battery Management More Effectively?

As previously stated, the BMS requires steady readings at various charge states. The vehicle must be in sleep mode for several hours to obtain a stable readout. To help the BMS attain a high degree of calibration, the following tasks are reasonably straightforward and don’t need to be carried out frequently.

  1. Occasionally leave the car unattended overnight or throughout the day without sending mode turned on to give it time to go to sleep for several hours.
  1. Avoid charging the vehicle every night. Various readings can be obtained by leaving the car in various states of charge throughout a range. Even once a month at an SoC under 50% can be beneficial.
  1. Switching off the 3rd party apps which keep the car more awake, and do not query this car which Tesla app unless essential when doing this above.

The objective is to accumulate several instances in which the automobile is completely asleep for 4-6 hours and at various charge levels.

What To Do If The State Degradation Of Your Car Is High?

You should try a few quick fixes to determine if this is a calibration or balancing issue before contacting Tesla:

Allow the automobile to run to a low charge; under 20% is preferable. If feasible, overnight, leave the car in this condition of charge for a few hours.

  1. After fully charging the battery, please turn off the automobile and wait until it stops providing electricity. If the car has previously indicated that charging is complete, disregard that message and check the energy/voltage/miles readout to determine whether charging is occurring.
  2. You can see the range enhance as you do this. It is normal. Repeat the method a few times if essential. You also should see it after every cycle the range enhancement.
  3. If your aspect calibration rather than the cell balancing is the actual problem, the car has not been left below fifty percent for some time, and then you can also focus on the BMS Calibration in the future.
  4. There are a few standard battery charging options included with every Tesla. You receive a mobile connector and three adapters with your Tesla purchase: one for a regular wall outlet (the NEMA 5-15), one for a more powerful 240 volt (or 40 amps of electricity) wall outlet home charger (the NEMA 14-50), and one for public charging stations (except Tesla Superchargers). For the absolute minimum, the NEMA 5-15 is also known as level 1 charging (120 volts using a regular ac wallet), but this is not advised.


As mentioned above, maintaining your Tesla’s daily charge at roughly 90% is crucial for preventing a battery calibration imbalance. Just keep in mind to set the 90% maximum charge limit.


What Is BMS Applied By Tesla?

Texas Instrument’s bq76PL536A-Q1 3-to-6 Series -Cell Lithium-Ion Battery Monitor and Secondary Protection is the foundation for Tesla’s BMS in the Model-S.

What Leads To BMS Failure?

Hardware issues or firmware flaws may cause thermal runaways in the event of a BMS malfunction. For instance, if a stop order is forgotten, the balancer may perpetually overcharge a cell. Even identifying the issue and blowing a fuse won’t halt the cell discharge in such a situation.

Is BMS Suitable For Charging?

An electronic regulator called a battery management system (BMS) keeps track of and regulates how rechargeable batteries are charged and discharged. Most gadgets that employ rechargeable batteries use several sorts of battery management systems.

How Long Will BMS Persist?

Burning mouth syndrome may endure for months to years, depending on the pattern of mouth irritation you experience. Rarely, symptoms may abruptly disappear on their own or lessen in frequency.

Posts Related to Electric Cars and Batteries

  1. Why does Tesla Car have a 12-volt Starter Battery?
  2. Does Tesla Replace Batteries For Free?
  3. Is Buying A Tesla With The Current State Of Battery Tech Worth It?
  4. How Much Energy Needs to Make A Tesla Battery?
  5. Tesla Battery Life Per Charge – Complete Guide 2024
  6. How To Calculate Mileage Of Electric Car?
  7. Tesla Batteries Are Dead, How To Open The Doors?
  8. Are electric cars worthless once the main battery dies?
  9. Tesla Model S Depreciation in The Uk 
  10. Model Y Charging Speed Chart 

About Author

Bharat Suthar

I am principal creator of electriccarexperience.com. I like riding Electric Car, UTV in mountains and Terrain, Also I try to share all the real life experience here in the site.I am really dedicated to write about my experience. I love doing all the outdoor activity including riding electric car, dirt biking and hiking.

Recent Posts