Armin wishes to keep engineering in his future - he will start pursuing a degree in computer science at Tartu University this upcoming fall.
Photo by Joosep Kään
Forget About Tesla Batteries
We already told you a little bit about our car batteries in our previous blog post, but it takes an army to build them. That is why, it’s not just our mechanics who are on the job, but also our electricians. We’d like you to meet Joosep Ress, Taavi Tiisler and Kevin Puust. Together with Peter Kipp (from our mechanics team), they’ve already done a ton. Our previous model upcycled some of Tesla’s battery modules, but the new model we are working on will feature a battery pack that our teams have designed and built from scratch!
Every module will consist of 130 smaller (21x71 mm) elements, which will be welded together between metal sheets, which enable us to connect them all together. Joosep Ress, who is working on the battery pack development tells us each pack consists of 18 smaller modules, which all together will form the pack itself. By designing our own battery, we get to play around with the density of it, making it possible to reduce its weight, while increasing its power. This, in turn, will help us keep the whole mass of the car smaller and develop a more efficient cooling system for the batteries to prevent overheating. We are especially stoked about the perk of our new batteries being, literally, brand new, which means we’ll get to use them to the fullest.
To build the battery, the team started with modeling, which means entire electronics and necessary details are built in 3D. Armin, our electronics team lead, says the team has done an excellent job as the progress has been enormous. Now, they are focusing on the actual building process.
This is the 3D rendering of our battery.
Reliable Maxeon Solar Elements
A great solar car needs… you guessed it - great solar panels. Anna-Mai Allikmäe and our last season’s project lead, this season’s mentor, Kaia Liisa Hakkil, are neck deep in preparations. Currently, they are all about calculations - that is to calculate and find out how to ensure the best efficiency. By the end of this process, we’ll know how many panels we will need and where we should put them on our car. They are really excited for Fall, because the upcoming school year will bring them some TalTech engineering students, who will help out with the building process.
Our new car will be decorated and powered with Maxeon solar elements, which will be produced at Solarstone factory in Viljandi. We are so stoked to use Maxeon’s single crystal silicon elements as they are one of the most efficient elements available, with an efficiency level at 24.3%.
We will be using Maximum Power Point Tracker on our solar panels, which will ensure the energy produced inside our panels will move where we need it to. In short, to drive our car, the energy will be going into our engines, and while our car is standing still, the same energy will charge our batteries.Electricians work hard all day.
If there’s one thing people know about cars, it’s probably how each vehicle must have an engine. So, who ensures our solar car having an engine? That’s the task of our powertrain team, led by Anton Lakovkin and Mattias Timm Rast, who have landed with their teams on sourcing our engines from GEM Motors. This time, our engines will be cheaper, but also significantly lighter. Their efficiency is very close to our top speed at 94%, which is an excellent result. Cutting some costs with our engines enabled us to buy three instead of two. This means, if something goes wrong, we’ll have a backup one, which is an incredibly helpful thing when it comes to building an innovative solar car.
Our powertrain team is also picking out the right sensors for our car. The vehicle needs a lot of different sensors to pick up information for us to analyze later. For example, our car has GPS, resistance, steering and braking sensors as well as motion ones for our suspension. The information collected will help us understand how our car is moving and performing, enabling us to catch on to potential issues ahead of time and make any needed adjustments. Our previous model had only a few sensors compared to the amount we have now, limiting the amount of information we could collect.
One of the biggest uptakings is building our test bench. The test bench will enable our electronics team to build their systems and test their functionality before installing it into our car. Among the stuff we get to test out are the main computer, previously listed sensors, and all else that doesn’t require a direct connection to the battery. The car will also have its own communication system that will connect our computer and controllers. This system makes sure every separate electronics communicates to others with ease via assigned IDs.
The computing system got a totally different design on our new model to increase its reliability and effectiveness. Armin said they focused on using newer components, more reliable plugs and outlets as well as developing water- and air-resistant covers that are easier to install.
Wires and Outlets
To connect all devices to each other, you need wires and a wiring team. Our superhero on this team is Rebecca Pärtel. She has chosen out all the outlets for the wiring and now she’ll have to map out every wire and outlet needed. After mapping, it will all be converted to our 3D model to see how long something has to be. The info will then be taken into our RapidHarness software to create a wiring wall, that will measure and organize the whole system.
Finally, our interior team consists of Herber Konnula and Anitra Lukjanov. They are designing plates for our electronics team as well as ensuring all buttons are within the reach of the drivers. They also have to make sure that the buttons make sense and are easy to use while driving. Same with any screens and rear cameras. Their job is trickier than it might sound - after all, they must take into account mechanical limitations as well as microcontrollers that will determine the functionality of screens inside the car.
This is what a 3D model plate for our back lights looks like.
Armin says the team has gone through tremendous growth as so many of the tasks, like creating the plates, are new to most of them:
“We watched through so many YouTube videos on how to use some of the software and I had to remember what I had done last year. Through combining all this knowledge, we figured it out.”
That’s it for today, thank you for joining us on this ride to the backstage and we hope you will look forward to our next engineering story - it’ll focus on the software team!
This story was written by Solaride’s marketing team member Laura Korjus and translated by Jette Stammer.