How longer-lasting, faster-charging batteries are coming via software updates

There’s an unbelievable amount of work going on right now to boost the performance of lithium-ion batteries. PhDs around the globe are, at this very moment, furrowing their respective brows, trying to eke out a few percentage points of extra energy density, shave a few minutes off of charging times, or add a few months to a given cell’s effective lifespan.

And then along comes a startup called Breathe Battery Technologies with an algorithm that promises to boost charging speeds by upward of 30 percent, all while preserving the lifespan of those cells. It’s part of a software package light enough to run on ancient embedded systems and small enough to be deployed via over-the-air updates. Best of all, it’s not theoretical: Volvo will feature this tech on the company’s upcoming ES90 sedan, and you can already find it on some smartphones.

Before we delve into the details, let’s quickly run through exactly what’s happening inside a battery. The charge provided by a battery happens when ions flow from anode to cathode, then journey across the electrolyte while carrying electrons with them. When it’s time to recharge, the process is effectively reversed, shoving those ions back across the void as quickly as possible.

These processes generate heat, and while some heat is fine, too much can damage the battery. Overheat your cells? Best case, their lifespan is reduced. Worst case? Well, you’d better stand back.

Charging, and particularly fast charging, is a careful dance between wasting time by charging too slowly and damaging the battery by charging too quickly. In most EVs, that dance is choreographed by a lookup table.

Similar to the fuel injection tables of yore that dictate how much juice to squirt into the cylinder for each combustion cycle in an engine, battery tables say precisely how much current should be applied to a given cell at a given temperature and state of charge.

The problem is, those tables aren’t very good.

To use these tables, you must know the battery’s temperature and state of charge. Find those figures, and the table tells you how much current can be applied to recharge the battery. It literally defines the charge curve for the cell. These tables are developed by the companies that make the cells (like Samsung SDI or LG Energy Solution) and the companies that put them in their cars.

The problem is that these lookup tables can be vague, lacking specific values for every temperature and state of charge. A lack of data fidelity makes for imprecise results. It’s like trying to draw a beautiful, flowing curve, but you can only use a few straight lines.

The tables are also inflexible, covering a narrow range of temperatures. “If you start with a table, you are fundamentally locked into the dimensions of that table. You are really bottlenecking yourself from the very get-go,” Ian Campbell, the CEO of Breathe, said.

Additionally, cars often waste a lot of energy to keep the batteries in a very narrow temperature range just to optimize the use of the lookup table. “You need to heat up or cool down the battery in order to prepare for this fast charging, and that also consumes a lot of energy,” Björn Fridholm, technical specialist in battery management at Volvo, added.

That takes us back to Breathe and its special sauce. You’re still working with the same basic factors: voltage, temperature, and current. Here, though, a software package (called Breathe Charge) determines the ideal charging rate with much more precision across a wider performance envelope than could be reasonably contained within a table.

“So you end up with this incredible level of fidelity and adaptivity across all timescales,” Campbell said.

To resurrect the metaphor from above, instead of jagged lines, you can now draw flowing charging curves that more closely match the ideal performance of the individual battery cells.

By mirroring that curve, cars equipped with Breathe’s tech will charge faster without putting any additional stress on the battery cells. And by providing a wider range of data, cars can charge more quickly even when outside their ideal thermal windows.

How much more quickly? Breathe and Volvo say this tech delivers a 30 percent reduction in charge time when going from 10 to 80 percent on a high-speed charger. But Breathe’s algorithm also delivers even bigger improvements when operating outside of ideal conditions. At zero degrees Celsius, that charge time improvement was 48 percent.

Why isn’t everyone doing this? It comes down to two constraints, the first being a deep enough understanding of the behavior of the individual cells. To gather that data, Breathe has a pair of labs in London where it stress tests sample cells from manufacturers.

Breathe determines a given cell chemistry’s strengths and weaknesses, breaking those chemical attributes into computer data, which drives the company’s digital physics model.

That then takes us to the second constraint: system overhead. While manufacturers and chipmakers love to talk about cars becoming supercomputers on wheels, the reality is that most of today’s cars still rely on embedded systems, dated chips with limited memory, and specs closer to yesterday’s graphing calculators than today’s GPU-laden rigs.

Efficiency is key. Breathe’s algorithm requires minimal processor cycles and fewer than 10 kilobytes of memory. The lightweight nature means that Breathe’s tech can be run on all sorts of limited hardware, even deployed via over-the-air updates — assuming those integrated systems are smart enough to be reflashed remotely.

Getting that efficiency means reliance on industry simulation and physics modeling tools, primarily MATLAB and Simulink. However, Campbell said that Breathe (which currently numbers about 75 employees) is working on future versions for the faster automotive processors to come.

Many of these future automotive processing chips also deliver some aspect of onboard AI, but it isn’t on the roadmap for Breathe. Campbell said he’s “bullish” on machine learning tech in this application but that it isn’t quite ready yet.

But the biggest constraint is the battery cells themselves. The amount of current they can receive is dictated by their construction and chemistry. Breathe Charge doesn’t violate the laws of physics; it simply ensures that the car is always feeding the right amount of current at the right time.

Volvo’s electric ES90, with Breathe Charge onboard, is slated to hit the market later this year. Fridholm confirmed the software could theoretically run on Volvo’s other EVs, including those already on the market, but he made it clear that we shouldn’t expect charge-boosting over-the-air updates hitting models like the EX30 anytime soon. “For now, we’re launching it on the ES90,” he said, and left it at that.

But Breathe won’t stop there. On its Careers page, the company currently has openings for sales-related positions in Detroit, Michigan — American auto manufacturers are clearly a target.

Breathe’s tech can also be found on the Oppo 8, where it’s optimized to extend battery health. Campbell said the company is also working to line up “a couple of cool customers” on the consumer devices front. In other words, hopefully we’ll be able to sample some fast-charging software in something a bit more affordable than a new Volvo soon.