As a model 3 Telsa owner you, along with almost everyone else that owns one have experienced a reduction in range during the time that you have owned it. But did you know that the range loss can be significantly reduced and even regained by doing 5 simple things? Really! I will show how 50% of battery range can be recovered just by following these tips.
Can I recover lost battery range on Tesla?
Battery range can be recovered on a Tesla by ensuring that the car frequently has the ability to take range readings. By leaving the car not charging, asleep, and off sentry mode for a few hours will allow the system to take readings and eventually recalibrate the range of the battery.
The way the Model 3 is designed, 3+ hours may be required for the batteries to settle and a reading taken.
The methods introduced here have been tried and proven on the Model 3 and I have gathered all the information I could including information directly from Tesla technicians. Hopefully this information will aid in you recovering some range back to your tesla and treat your car as best as possible to prolong the battery life.
Battery Range Recovery of Tesla
After experiencing range loss and hearing from many other Model 3 Tesla owners of the same issue it seems nearly every Model 3 experiences a significant loss of 100% indicated battery range within just a couple years of being new.
Battery range loss can be recovered by following these 5 rules:
- Leave the car for 3+ hours for the battery cells to balance and a range system calibration to be completed. (An OCV can be taken)
- Leave the car during the 3+ hours not charging and “asleep”.
- The car must be off sentry mode to make a battery range calibration reading.
- Quit charging every day. Charge the battery less frequently to allow readings to be taken at different battery capacities.
- Only charge to 100% once in a while before a long trip.
The key to an optimal battery calibration is to leave the car with sentry mode off and not plugged in and “asleep” for at least 3 hours whenever possible.
After implementing these steps and following them consistently, after about 3 months a new range calibration was noticed. Then again after about another 3 months was recalibrated again both times increasing the 100% range estimate.
7 months after following these 5 tips, overall range of the Tesla increased from 270 miles full range to 290 miles full range. Again the original range capacity when new was 310 miles. Half of the lost range was recovered!
This information largely comes directly from a Tesla Technician even though Tesla does not have a formal required charging procedure.
I will now cover how Tesla determines the battery range and what may cause it to decrease over time.
Key Takeaway:
For the Tesla to perform a battery reading and best estimate the range capacity of the battery you must : Allow the BMS to take OCV readings whenever possible. Turn off sentry mode while at work. TeslaFi can be set to allow the car to sleep.
More loss of range on the Model 3 than the Model X or Model S, but the rules here to recover battery range may apply to all models.
Tesla Technician Provided Information
Tesla does not have an official charging regimen but understanding a few key things about the car and the battery will help you to do the best things for your car and prolong the life of the battery.
Tesla Technician said:
“If you can let the vehicle rest without being plugged in for a few hours, that will help the vehicle more accurately calculate the battery capacity. The battery needs to rest (parked and not charging) for a few hours around 50% and above 80%. We recommend using the scheduled charging feature and setting it to charge in the middle of the night to 90% and avoid charging to 100% unless you’re taking a long trip.”
and also said,
“Regular deep discharges should be avoided when possible. If the battery has a large depth of discharge to a low state of charge (red zone, allowing the battery to rest for a few hours before recharging will minimize stress on the cells if convenient, scheduled charging could be used.”
How Tesla Determines Battery Range
Battery degradation is a normal occurence for a Tesla car battery and gradually over time the battery life is reduced. BUT, there may be other factors involved. If the battery range is reducing more than it should it may be due to the BMS system which BMS system is responsible for charging and monitoring the battery as well as computing the estimated range.
What determines the battery range in a Telsa?
The BMS correlates the battery’s terminal voltage to the capacity of the battery and constantly refines and recalibrates the relationship between the voltage and capacity and determines the remaining range in miles.
The Battery Management System (BMS) frequently takes readings of the open circuit voltage (OCV) of the battery along with the battery capacity and stores the data. With enough data points, the BMS is able to determine the range based only on the voltage of the battery.
When does the BMS take OCV readings?
The Tesla Battery Management System takes voltage readings once the battery cell voltages level out. This requires some time of the car parked not in sentry mode, not being charged, and “asleep”.
The main high voltage contactor of the battery must be open and the voltages in every group of parallel cells must stabilize. Meaning, when the cars stops driving it will have slightly different voltages in the battery cells and will level out the voltages so that all of the cells remain of a similar voltage.
Battery Construction
Battery construction helps to understand why time is required for a voltage reading to be taken and stored as data to later be used to estimate battery life.
For the model 3, the battery cell voltages take significantly longer to stabilize than for the model S or X because of battery construction.
Tesla batteries have a resistor in parallel with every group of cells to balance the voltage in the cell pack. The resistors allow the low cells in the parallel group to charge more than the high cells in the group and bring them all closer to a similar charge.
The resistors are also the primary cause of vampire drain on the batteries and for the Model 3, to reduce the vampire drain, higher resistance resistors were put in place. This reduces vampire drain but results in longer wait times for the battery cells to level out.
The estimated time for the model S or X to balance and be ready for an OCV reading is 15-20 minutes and in the model 3, can be 3+ hours.
For the Model S or Model X, a voltage reading is taken more frequently and at different points of the battery charge since less time is required for the battery cells to balance.
With the model 3 if you are taking frequent short trips throughout the day, there is no time for OCV readings to be taken.
Why Battery Range is Lost
Why is Tesla battery range slowly reduced?
The primary cause of battery range loss may be from a range estimation issue and not actual capacity loss. Inaccurate estimates of the battery system may result if the car is not left alone for long enough “asleep” at different battery capacities.
If the Battery Management System (BMS) goes for a long time without taking OCV readings or running a calibration then the BMS estimate of the battery capacity gradually gets further from the battery’s actual capacity.
To prevent the car from running out of charge before the range estimate reads 0, the BMS errors with a conservative estimate so that the estimated capacity is never more than the actual capacity of the battery.
Also, important to note!:
Sentry mode keeps the contacts engaged and no voltage readings are taken while sentry mode is active.
This leads to an OCV reading at home, after the battery is charged and does not result in enough data points of battery voltage at different capacities to make an accurate range estimate.
If the accuracy of the BMS never improves then the estimated capacity vs actual capacity continues to drift apart.
In a car like the Model 3 with long voltage stabilization times, leaving the car on sentry mode and charging every day will result in a less accurate battery range calibration.
Charging every day means OCV readings are taken at the same charge level which does not provide data for the BMS to accurately estimate the range.
Tesla battery range also gradually declines from a normal reduction in the capability of the chemical reactions in the lithium battery, but by following the 5 tips in this post, you will reduce the range loss as much as possible.
1. Leave the Car for 3+ Hours
For the Telsa Model 3, according to Tesla technicians, it may take 3 or more hours for the batteries to settle. For a battery voltage to capacity reading to be taken the car batteries must have enough time to settle and a reading taken while the car is “asleep”.
For other models, the battery cells balance themselves much quicker and there is no extra effort necessary to allow the batteries to settle for a voltage reading for the BMS.
A simple solution to aid the car in being able to take a reading to calibrate the range of the battery is to leave the car to sleep for several hours several days a week. Leaving the car while you are at work is ideal. Or not charging the car every night and allowing it to sit and take a reading at a lower battery level is another great solution to this range loss issue that most Model 3 owners are experiencing.
2. Not Charging during 3+ Hours
If the car is charging or is “awake” battery voltage will not be checked by the battery management system.
Allow the car to “sleep”. How do I allow the car to sleep?
Allow a Telsa to sleep by leaving it off sentry mode or any other similar mode and by not opening the app or approaching the vehicle.
The Telsa will sleep after it has been idle for some time, generally after about 30 minutes.
But, the car will not sleep if it is in sentry mode or dog mode, etc. It will also “wake up” when you open the app. All of these things require the computer system to be on so you should leave it alone off the app and off sentry mode to let it sleep.
This can be programmed with your app to tell the car to sleep whenever you want it to. It will automatically do this but only if it is not disturbed.
3. Off Sentry Mode during 3+ Hours
If the car is left on sentry mode then the contacts of the battery remain closed.
With closed contacts, an Open Circuit Voltage (OCV) reading cannot be taken.
This means that if you drive your Model 3 to work every day, leave it parked all day on sentry mode, then drive it home and plug it in, then the only chance it will get to take a voltage reading for data for the battery management system is at night after the car is fully charged.
Leave the car off sentry mode when you are leaving it for several hours. At work is a great opportunity since you may be there for 7-8 hours and that will allow a battery reading to be taken at not a full charge.
4. Quit Charging Every Day
Another great time to allow the car to sleep and take battery readings at different capacities is by not charging every day.
Only charge the car every couple days when possible to leave it to take a battery reading at different ranges.
If you normally charge to 90% every day and only use about 20% of the battery capacity getting to and from work, try charging the car every third day or so to allow the BMS to take readings at 80% 60% and 40% capacity.
Of course you do not want to be caught with limited range if you have to drive somewhere unexpectedly, but you get the idea. If you only use a few miles a day, skip charging for a day or two and this will help you to recover lost battery range because the car will be able to make a more accurate estimate with readings taken at different battery capacities.
5. Charge to 100% Only Occasionally
For long road trips, it is acceptable to charge the battery to 100% but Tesla recommends only charging to 100% occasionally. Tesla says that by nnot regularly charging to 100% you will prolong the life of the battery.
This is due to not putting extra strain on the battery and not charging it to its’ maximum capability.
Hopefully you are not commuting every day where you have to use up the maximum amount of battery every single day so since this is the case, simply leave the battery charge maximum at 85%-95% and do your battery the favor of letting it relax!
Key Takeaway
After researching, reading, and reaching out to Tesla, contact with a service center member talking about battery degradation, and a phone call with a virtual tech team technician I have gathered this information to help you recover a significant amount of lost battery capacity and range of your Tesla Model 3. I learned how and when range is calibrated and knowing these things help you to know the following:
- Turn off sentry mode occasionally
- Leave the car 3+ hours
- Do not charge the car every day if you can avoid it
- Charge the battery to 100% only occasionally
You do not have to to ALL of these things, but what you do need to do is allow the car several hours while asleep to take readings of the battery in order to make the most accurate battery range estimation.
By doing these things if you are not already do them, you will find that after several months, the car will recalibrate the battery range all on it’s own and it will increase!
