Inside Porsche’s battery lab: The tech behind your next electric car

Electric cars have burst onto the scene over the last decade. Porsche unveiled its first electric car of the modern era with the Taycan in 2019, before the Macan joined its all-electric sibling in 2024.

Automotive historians will be quick to point out that Ferdinand Porsche experimented with electric power all the way back in 1898 with the Egger-Lohner C.2 Phaeton. Porsche has come a long way since and to get a better understanding of what goes into a modern Porsche EV battery, I took a look behind the scenes.

Porsche experts spoke to me about the conflict between range and performance, battery lifespan – and how to avoid ‘sudden death’ – how the company predicts track times, and how testing lies at the heart of everything.

What’s the right capacity for an EV battery?

Nestled in the rolling hills of Baden-Württemberg in Germany lies Weissach, home of the Porsche Development Centre. It’s in Weissach that I find myself and while it’s tempting to examine the Porsche 718 prototypes that litter the site, I’m more interested in finding out what might power Porsche’s future electric sports car.

Range still dominates conversations about electric cars and this is the first thing that I dive into with Porsche. For a long range you need a high capacity, but that will result in a heavy battery with higher CO2 costs. For the best performance you want to increase the power to weight ratio, which would suggest a smaller battery to make it lighter, without giving up power that it might deliver. There’s a conflict here for a sports car manufacturer like Porsche.

Porsche is keen to discuss this point, highlighting that range can’t be the sole focus when thinking about the best battery for an EV model. I’m fed familiar statistics: that 95 per cent of journeys are under 200km (125 miles) and less than 2 per cent are over 300km (186 miles), but customers still want long range.

It’s a familiar story, with rapid charging usually cast in the role of hero, so drivers can get back on the road in less than 20 minutes. That gets me thinking about the forthcoming electric Porsche 718. With this model being smaller, would Porsche consider fitting it with a smaller, albeit highly efficient, battery? Rumours suggest it will have a capacity somewhere in the region of 89kWh.

Efficiency holds the key to using smaller batteries and you just have to look at the difference between the first and second-gen Taycan models to see how this will work.

The new Taycan offers more energy, a higher charging current, lower fast charging temperatures, a higher discharge rate (which means greater available power), lower weight and a higher energy density than the old model. Essentially, greater efficiency in all areas. Will customers accept a slightly lower range when all the other benefits stack up?

For now Porsche isn’t revealing any figures, but I get the sense that’s the direction the argument is heading. Using a smaller battery also means using less materials and a lower CO2 demands.

How to preserve the capacity of your EV battery

Chemistry is unavoidable when talking about EV batteries and I’m introduced to the concept of ‘sudden death’ of a lithium-ion battery. That’s when a battery completely fails. Porsche tells me that it takes ‘abusive’ use for this to happen, but I’m also told that there’s no way to preserve a lithium-ion cell’s full performance through the life of the vehicle.

That’s because battery aging is unavoidable: Carlos Alberto Cordova Tineo, development lead in high voltage batteries at Porsche, tells me that there’s an initial drop, where some capacity is lost. This happens in all lithium-ion cells, not just in cars: it’s part of the battery chemistry, unavoidable and normal.

But beyond the initial drop, there’s plenty that can be done to preserve the performance of a battery and if you’ve ever owned a smartphone, you probably already know this. Fast charging, keeping your battery fully charged, and exposure to high temperatures, will reduce the lifespan of your battery. All three at the same time puts much greater stress on the battery.

While the car will manage the battery condition – regulating temperature for example – there’s plenty you can do yourself. Carlos’ advice would be to store your car somewhere that’s temperature controlled (like a garage), protected from extreme cold and heat; to charge wherever possible at lower currents like a 7kW home charger; and to limit to the total charge you put into the battery – if it doesn’t need to be at 100 per cent, don’t charge it to 100 per cent. This will give the battery the best chance of retaining its capacity.

Of course, Porsche tests and tests its batteries, subjecting them to the highest charging rates in high heats to ensure that the battery remains safe. While the average owner rapid charges their car 15 per cent of the time (according to Porsche), Porsche tests it at 50 per cent, always looking to go beyond what would be expected in typical usage.

The battery in your Porsche EV is expected to last for 15 years and offer over 300,000km (186,000 miles) of driving.

How Porsche knew Taycan would smash the Nürburgring record

Porsche took headlines in 2022 when the Taycan Turbo S stole the production car record on the Nürburgring from the Tesla Model S Plaid. As impressive as that was, Porsche knew that was going to happen long before test driver Lars Kern got behind the wheel.

Housed on a subterranean floor in a Weissach building, Porsche’s high-voltage test bench allows the company to test cars before they even exist. Before a prototype is built, the bench can be rigged to test how the car will perform. Step into the test bench and it’s hard to picture a car, but sitting at the heart I find the front and rear motors from the Porsche Macan, the electronics and the transmission.

Like the embryonic humans in the Matrix, it looks like a half-formed Macan on life support: there are suspended fluid reservoirs, wires everywhere and a distinct hospital feel to things. Each corner sees a turbine unit that represents the wheel with familiar orange cabling linking all the high voltage parts together. Like a Magic Eye picture, stare long enough and the car will start to appear.

One thing that’s ominously missing is the battery. Two floors below, I find the 100kWh battery in its own container. Again, orange cables lead through the ceiling making their way to the rest of the test bench, while the battery itself is rigged with wires and sensors.

The test bench allows Porsche to make changes, both in physical hardware and on the software side. What happens if you swap to a new motor? What’s the impact on the battery? What happens when charging with a new standard of connector? What happens when you push new software designed to improve performance? What happens when all this is done at extreme high or low temperatures?

Porsche can also see what happens when the car or battery is subject to extreme temperatures, when the battery is completely immersed in water, or exposed to high pressure jets. (Shocker: nothing, it all continues to work as expected.)

Using the bench, Porsche can test what happens when the Taycan Turbo S (or any other model) hits the Nürburgring (or any other track). “The test bench results provide valuable insights for potential optimisations and lap time predictions,” Otmar Bitsche, senior consultant battery development, tells me.

What happens when an EV battery reaches the end of its life?

Much of the story around lithium-ion batteries focuses on rare materials. Porsche only uses NMC batteries (containing nickel, manganese and cobalt), as they offer the performance that Porsche needs for its cars. Sitting under the umbrella of sustainability, battery recycling is something that Porsche is actively engaged in.

The figures are encouraging too, with Porsche saying that 90 per cent of natural materials can be recovered. The aim, over time, will be to recycle batteries and use recycled materials in new batteries. But where are these batteries coming from, as most Porsche owners are still driving their Taycan or new Macan?

In another building on the Weissach campus, I find my answer. Porsche is crash testing electric cars and once a battery has been involved in such testing, it’s off to Cylib as part of the pilot scheme for battery recycling. The aim is to create a circular economy and reduce dependence on sourcing rare materials from countries outside the EU. Naturally, there’s also regulation coming in to enforce this over the next few years.

At Cylib the battery is shredded into what’s called a ‘black mass’. This then goes through a hydrometallurgy process to extract those rare metals, which will then be put into new batteries. The next phase of the pilot scheme is to test the viability of batteries with reclaimed materials to ensure that the battery meets Porsche’s standards.

But I’m more interested in examining what’s left after a side pole impact. I step into Porsche’s cavernous crash test facility and it’s the closest thing to a Bond villain’s lair that I can imagine. Simon Maurer, governor of safety systems at Porsche, tells me that he has to sit down and order the models that he then destroys through the year.

I examine the remains of the electric Macan after the impact test and I’m surprised by how well the frame has survived. The NCAP video above shows this impact (along with a load of other tests) and reassuringly, there’s little damage to the battery housing in the floor. Sure, your car might be written off, but at least you’re safe.

Ultimately, that’s the point of all this. Ensuring, through testing, modelling and striving for the highest quality standard, that your EV battery is safe and that it’s going to give you many years of driving pleasure.