What Does Regenerative Braking Temporarily Reduced Mean On Your Tesla?

As technology advances, we have become aware of how much energy we are consuming and how it affects our environment. This awareness has led to some remarkable changes in the technology around us, especially in the automobile industry.

With each new iteration of a car comes a promise of greater miles with lower fuel. But perhaps the biggest change is the slow but sure transition from gasoline vehicles to electric vehicles or EVs. In this article, we will talk about one of the fascinating aspects of EV technology, and that is Regenerative Braking. 

Here is what Regenerative Braking Temporary Reduced means

If you own a Tesla, then there is a chance you’ve come across the message that the ‘’Regenerative Braking is temporarily reduced’’. To a new Tesla owner, this message may be unclear but what it simply means is that the regen braking won’t function as it should.

That means it may take longer than usual to slow down the car or even bring it to a stop. You should know that this is normal, and there is no need for you to take your car in for maintenance. There is absolutely nothing wrong with your EV.

Here are the three main reasons why your regen braking may be temporarily reduced. It is either because your battery is fully charged, the battery is cold, or there is too much charge for the car’s battery to keep up with.

Regenerative Braking Temporarily Reduced
Regenerative braking temporarily reduced (Photo credit: teslaownersonline.com)

01. Your Battery is 100% charged

One big challenge EV owners face is juicing up their car batteries. Despite the advanced charging technology, it still takes a considerable amount of time to charge up and get going once your batteries run out. To avoid this, most people charge their EV over the night to ensure it gets to 100%. This is great because you get to have the full range capability of your EV without worrying about running out. At the same time, you will be trading one of the nifty features of your EV for that full charge and that is regenerative braking. Apart from slowing down the car, regenerative braking also charges the battery. Both actions are performed simultaneously. But when your batteries are fully charged, regenerative braking stops working because the car is less energy efficient. To avoid this, you should keep your batteries between 90% and 95% charge. 

02. The battery is too cold

If you own an EV then be sure to watch out for winter. The colder it gets, the harder it is to charge the battery. This is because when it gets too cold, the electrolyte in the Lithium-ion battery becomes dense. The denser the electrolyte is, the more difficult it is for ions to move between the electrodes. Since this process is required for the battery to charge, it therefore means that as the battery gets cold, it becomes difficult to charge it. The temperature a which the battery stops charging completely is about 32•F (for Tesla’s) and may differ for other EVs. But once it gets below 68•F, regenerative braking is reduced because the charging capacity of the batteries is reduced. However, once the batteries have warmed up (after driving for a few minutes), then regenerative braking will be restored. 

03. Too much charge for the battery to keep up with

The third reason why regenerative braking may be reduced is that the batteries get too much electricity in an instant. This happens if you’re at a high speed and then suddenly decelerate the car to a stop. All that speed will be converted to electricity and fed into the battery. This could overload the battery and to prevent this, the vehicle’s control unit will temporarily disable regenerative braking. At this point, the mechanical braking systems will kick in. 

What is Regenerative Braking?

One of the most common actions we perform when driving a car is braking, whether we only want to slow down for a moment or come to a complete stop. This is something any driver has done countless times, however, most people don’t consider how much energy is wasted in the process. The car’s kinetic energy is converted to heat as the driver matches the brake pedals.   

Well, that was the case for most old cars, but today, most cars especially hybrid or EVs come with regenerative brakes. 

Regenerative brakes are a technology that allows all the kinetic energy of your car to be converted into electric energy that can be used in charging the car batteries. So instead of wasting all that energy in the form of heat, we use it to give our car batteries an extra boost. The technology was unveiled in 1967 by America Motors Company (AMC). But it only became popular with the growing number of hybrids and Electric vehicles. 

How Regenerative Braking Works

The reason why regenerative braking systems became popular in EVs is that they are driven primarily by an electric motor powered by a battery. When accelerating, the electric motor provides the torque that rotates the wheels. But when decelerating (slowing down), the electric motor acts as a generator and supplies electricity to the battery. The regenerative braking system can be triggered in two ways; the first is when the driver relieves the pressure on the pedal (throttle).

Regenerative braking illustration (Photo credit: EVUp)

The central computer of the car detects this and immediately activates regenerative braking. The force of the regen will depend on the pressure applied to the accelerator pedal. The lower the pressure applied (as the driver removes his foot from the pedal), the higher the regenerative braking force. This system where the driver can accelerate and decelerate the car using one pedal is known as One pedal driving. This is the system that commonly found in Teslas.

On the other hand, some EVs have the usual brake pedal and when the driver applies pressure on this brake pedal, regenerative braking is activated. This is similar to the normal two-pedal driving system found in most automatic vehicles. Either way, regenerative braking is usually supported by the normal mechanical braking system in case an emergency stop is required. That is if the driver intends to bring the vehicle to a stop instantly. 

The reason is that regenerative braking is perfect for a slow and gradual stop. This hybrid brake system may seem overkill, but it has its own advantage. The use of regen braking with mechanical braking prolongs the life of the mechanical braking system by reducing the rate at which the brake pads wear out. 

Frequently Asked Questions

How do I know if my regenerative braking is reduced?

You will see a blue snowflake icon on the car touchscreen. This means your car batteries are too cold and because of this you may not have access to regenerative braking. The icon disappears when the battery warms up. 

At first, most Tesla users would see a message displayed on the screen telling them that the regenerative braking is reduced. But this created so much confusion as some drivers weren’t sure if it was safe to drive. In a bid to clear this up, the message was updated and now says “Limited deceleration when the accelerator is released. OK to drive – Use brake pedal as needed.” 

Using the Tesla Energy bar

The Energy bar or power meter on your touch screen lets you know how power is being used or generated by your Tesla. The power meter is a thin line with a bar that moves left or right. When the bar moves to the right, it shows that your Tesla is using up power which happens during acceleration. When it moves to the left, the bar turns green and this indicates that your Tesla is generating power which will charge the battery. Occasionally you may see green dots at the left side of the energy bar. This indicates that the regenerative braking will be reduced at that point. The more the dots, the lower the regenerative braking.

How can I turn off regenerative braking on my Tesla?

You can not turn off the regenerative braking on your Tesla. There was an option for Tesla drivers to reduce the amount of regenerative braking by choosing standard or low. But this has been removed and the whole process is now set at a default level for all Teslas. Tesla drivers have very little control over the system by toggling the stopping mode between creep and roll. 

Does regenerative braking reverse the motor? 

Yes. Regenerative braking reverses your Tesla’s motor. When the motor runs in the reverse direction, it acts like a generator that charges the batteries. When the pressure is applied to the accelerator pedals, the motor receives power from the battery and once again drives the wheels. 

How efficient is Tesla’s regen braking?

Technically, no system is 100% effective because energy loss is inevitable. However, with regen braking, you can recapture a certain percentage of the energy wasted during braking. While there are no specific data that shows how much energy is recaptured, the average rate is between 60 – 80%. 

The energy recaptured depends on the model of Tesla you own. Tesla generates about 60 KW with each hard regen braking. But this limit is different with each Model and can be changed with a software update. So if your Tesla model has a higher maximum regen output, then that only means it captures more energy when braking. 

Does Tesla Regen use brakes?

No. The regenerative braking system doesn’t make use of mechanical brake pads. However, when the regenerative brake isn’t available, your Tesla switches over to the mechanical brake. The switch is often smooth, however, if your Tesla model has only one pedal, it may take some time to get used to it. 

Can you adjust regenerative braking on a Tesla?

No. Regenerative braking on Tesla is performed automatically by the system. The driver has no direct control over how much regen braking power is applied. 

Conclusion

Regenerative braking is not a new technology. But we are only beginning to see its application on a large scale as EVs and Hybrid cars become more popular. Is it a perfect technology? No, there is still room for improvement. However, what has been achieved so far is impressive. If you own a Tesla or any other EV, you’d soon see the value of this technology and it is only normal to have some questions. This article has addressed common questions concerning regenerative braking and hopefully, you’ll find it helpful.