7 Reasons Why Tesla Stuck At 99 Charging? (Fixed It!!)

Some Tesla owners have reported a problem with their cars’ charging process: the car gets stuck at 99% and does not reach 100% even after hours of waiting.

This article will explain what causes this issue and how it can be resolved.

Why Tesla Stuck at 99 Charging?

The reason why Tesla gets stuck at 99 charging is not a defect or a malfunction, but a normal and expected behavior of the battery management system (BMS).

Balancing occurs when the battery pack is close to full charge, usually above 90%. The BMS slows down the charging rate and starts to distribute the current among the cells that need more charge.

Therefore, when the car displays 99%, it does not mean that it is almost full, but that it is balancing the cells. The car will eventually reach 100% when the balancing is complete.

What is Tesla’s Recommendation Here?

Tesla recommends that owners charge their cars to 100% only when they need the maximum range for a long trip, and to limit daily charging to 80% or 90%.

This is because charging to full or near full levels frequently can degrade the battery capacity over time.

Moreover, charging to 100% can reduce the regenerative braking ability of the car, which recovers energy from braking and deceleration.

5 Tips to Avoid Getting Stuck at 99 Charging

To avoid the issue of getting stuck at 99%, Tesla owners can follow these tips:

1. Charge the car in range mode instead of standard mode. Range mode prioritizes cooling the battery pack, which can speed up the balancing process.

2. Charge the car at a lower current setting, such as 12 amps instead of 40 amps. This can also help with cooling and balancing.

3. Charge the car in a cooler environment, such as in a shaded or air-conditioned garage. High temperatures can affect the battery performance and increase the cooling and balancing time.

4. Charge the car only when needed, and avoid leaving it plugged in for long periods of time. This can prevent unnecessary cycling and draining of the battery pack.

5. Let the car finish charging to 100% once in a while, such as every few months. This can recalibrate the BMS and improve the accuracy of the battery gauge.

How To Fix Tesla Stuck At 99 Charging Problem?

Some of the possible problems that can affect Tesla battery charging are:

#1. Balancing

The battery pack is balancing its cells, which can take a long time and slow down the charging rate.

This is a normal and expected behavior of the BMS that ensures optimal battery performance and longevity.

Solution

The solution for this problem is to wait patiently until the balancing is complete.

Alternatively, you can lower your charging limit to a lower percentage if you don’t need the full range.

#2. Degradation

The battery pack is degrading over time, which can reduce its capacity and efficiency.

This is an inevitable and natural process that affects all batteries, especially if they are frequently charged to full or near full levels.

Solution

The solution for this problem is to limit your daily charging to 80% or 90% unless you need the maximum range for a long trip.

This can preserve your battery capacity and extend its lifespan.

#3. Overheating

The battery pack is overheating due to high ambient temperature, high current level, or insufficient cooling.

This can trigger the BMS to limit the charging rate or stop the charging process altogether to protect the battery from damage.

Solution

The solution to this problem is to charge your car in a cooler environment, such as in a shaded or air-conditioned garage.

You can also charge your car in range mode, which prioritizes cooling the battery pack.

Additionally, you can charge your car at a lower current setting, such as 12 amps instead of 40 amps.

#4. Undercooling

The battery pack is undercooling due to low ambient temperature, low current level, or insufficient heating.

This can lower the battery’s ability to accept charge and increase its internal resistance, which can slow down the charging rate.

Solution

The solution to this problem is to charge your car in a warmer environment, such as in a heated garage.

You can also use the Tesla app or the touchscreen to preheat your car and battery before charging.

Additionally, you can charge your car at a higher current setting, such as 40 amps instead of 12 amps.

#5. Incompatibility

The charger is incompatible with the car or the power source. This can cause communication errors, voltage fluctuations, or current interruptions that can affect the charging process.

It is recommended to use only Tesla-approved chargers and power sources for your car.

Solution

The solution to this problem is to use a compatible charger and power source for your car.

You can check the user manual or the Tesla website for the specifications and requirements of your charger and power source.

You can also contact Tesla customer support if you have any doubts or questions about your charger and power source.

#6. Damage or Dirt

The charger is damaged or dirty, which can prevent it from delivering a stable and consistent charge to the car.

It is important to inspect and clean your charger regularly and replace it if needed.

Solution

The solution for this problem is to check the cable and connector of your charger for any damage, dirt, or looseness.

You can clean them with a soft cloth if needed and plug them firmly into the car and the power source. You can also replace your charger if it is damaged or faulty.

#7. Software Issues

The software is outdated or corrupted, which can cause glitches, bugs, or errors in the BMS or the charging system.

It is advisable to update your software regularly and report any issues to Tesla customer support.

Solution

The solution for this problem is to check the software version of your Tesla and make sure it is up-to-date and compatible with the latest features and functions of the BMS.

You can update your software through the Tesla app or the touchscreen in your car. You can also contact Tesla customer support if you encounter any software issues or errors.

Tesla’s battery technology is one of its key advantages in the electric vehicle market. By understanding how it works and how to maintain it properly, Tesla owners can enjoy their cars’ performance and range for years to come.