Aha Nexcruise: Cruise control & energy management system on a Nexon EV

By turning regen off, you don't lose momentum sharply and the vehicle glides smoothly, speed dropping gently only due to rolling & aerodynamic resistance.

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My Nexon EV is almost 8 months old and I have clocked over 8K kms. Not the most impressive stats, but having driven it in both city and highway conditions including my 2600Km round trip between Chennai and Bhubaneshwar, I feel confident that I know my car quite well. Especially its quirks and idiosyncrasies, and how to optimize it for my use.

The powertrain being the single biggest difference between EVs and ICEVs, most EV owners aim to master the "EV style of driving" which involves careful throttle inputs, single-pedal driving etc. But in this quest to extract better mileage, driving can be a bit taxing on the mind and the right foot. The fact that the Nexon EV comes without cruise control or selective regen adds to driver workload. This is especially apparently during long drives when the right foot starts hurting as you feather the throttle, trying to exert just the right amount of pressure on the pedal so that the car doesn't start to brake/regen or doesn't consume more power than strictly necessary to maintain the current speed. One needs to frequently monitor the power meter and adjust force on the accelerator pedal accordingly, which sadly affects the overall experience and joy of driving. This is not as much of a problem in ICE vehicles as there is no regen. if you lift off the accelerator pedal, the vehicle will coast, albeit with engine braking which will depend on the gear you are in. So you don't lose as much energy. But in EVs, regen is not really effective over short bursts and only serves to slow the car down without significant increase in charge levels (some energy is still being lost to friction).

Enter the Aha Nexcruise, an absolute game changer for Nexon/Tigor EV owners. It has been developed by Aakash of Aha 3D Innovations, an early Nexon EV owner who experienced the aforementioned pain points himself and decided to do something about it. From concept to delivery in about 8 months, the Nexcruise - which is aptly termed an "EV Energy Management System" - was created with inputs from many other Nexon EV owners. I was one of the early adopters and had confirmed my order in July 2021. I just received my unit last week and have driven 800 kms with the Nexcruise. This review is based on my experience so far.

How does it work:

Most modern cars (EV and ICE alike) have drive-by-wire systems, which means the accelerator is not connected to hydraulics but to a sensor and ECM which interprets your inputs and commands the engine to deliver appropriate power. This 2-min video on the Engineering Explained channel on YouTube does a great job of introducing the concept of electronic throttle.

Basically there's a data cable that goes from the sensor on your accelerator pedal to the car's ECM (in this case VCU, as there's no combustion). The Nexcruise unit is inserted between the pedal's sensor and the VCU, with another cable connecting to the vehicles' OBD port. There's an LED strip (also connected to the Nexcruise unit) which gives a visual indication of the device's functioning. The control unit is a dial with buttons for its multiple functions. The dial connects to the main unit through Bluetooth. The Nexcruise unit itself resides close to the OBD port and is hidden from view.

The experience:

While the Nexcruise started off primarily as a cruise control, and that is one of its primary functions, it offers much more than just cruise control. I want to start with the Coast function.

As explained earlier, one of the biggest challenges with the Nexon EV is its lack of selectable regen. That means the user cannot decide how aggressive the braking/regen should be. Nor can the user turn it off completely. In D mode, regen is quite strong and less so in S Mode. But regardless, it's always there. And that's a problem specifically on highways as you may want to take your foot off the accelerator pedal without the vehicle braking. The Coast feature of the Nexcruise does just that (indicated by a blue light on the LED panel). By turning regen off, you don't lose momentum sharply and the vehicle glides smoothly, speed dropping gently only due to rolling & aerodynamic resistance. This is equivalent to coasting in Neutral. However, should you need to slow down quickly, pressing the brake pedal immediately kicks in regen and the kinetic energy is harvested back to the battery (however minimal it may be). Releasing the brake pedal resumes the coast behavior and the vehicle continues to glide, albeit at the reduced speed.

Now we come to the primary feature i.e. the cruise control. It works pretty much like any modern cruise control system. Press the main knob to activate cruise (indicated by a green light on the LED panel), turn the dial left or right to increase or decrease cruise speed. If yo accelerate above the set cruise speed, releasing the accelerator will resume cruise once you drop to the set speed. If used in conjunction with the Coast feature, the deceleration from the higher attained speed to the lower cruise speed will be very gentle. Braking when in cruise mode deactivates the cruise function. Despite connecting to the main unit through Bluetooth, the dial is very responsive and I was able to control the car's speed without using the accelerator pedal at all.

Finally, there are a few other features like Eco and Deep Eco that limit the power used, irrespective of accelerator inputs. I didn't need to use these features on the recent trip as I wasn't hypermiling, but I will put them to use in the near future as I aim to cover the distance from Chennai to Bangalore with a single FC stop.

Concerns:

There were many concerns about the Nexcruise system affecting the car's electricals/electronics and/or warranty implications. I'm not oblivious to these aspects and I acknowledge the risk. However, two factors helped alleviate these concerns:

• Aakash has been super transparent about the entire process, even admitting that the first version had a bug which delayed the rollout. There were some security issues which were detected and addressed during public beta testing. Everything has been documented and available on their YT channel. This inspires confidence that the system has been rigorously tested and is safe to use.
• Given it's plug-and-play nature, and the fact that it can be installed (and hence removed) by the user without any expert involvement, it is hard to see why/how it would invalidate the car's warranty.

Conclusion:

The fact that Tata left out cruise control from the Nexon and Tigor EVs sucks. Whatever the logic, it's hard to justify the omission of something that greatly enhances the user experience. But in hindsight, I'm glad they did because that opened the door for this collaborative innovation. Having installed and driven with the Nexcruise, it has transformed my highway driving experience completely and I believe every Nexon EV & Tigor EV driver can benefit from it. There's news of the new upgraded Nexon EV having cruise control, and I hope it comes with the ability to turn off regen. If not, the Nexcruise is worth the buy just for the Coast feature alone.

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