Electric cars beat out gas vehicles in just about every imaginable way. Except one. It’s not so much the range (EVs get about 300 miles between charges these days); it’s the actual charging time. EVs require 20 minutes or more to recharge—a lifetime for people accustomed to quick trips to the gas pump.
What’s the breakthrough? The new cable sends more current than the cables we have today—a whopping 4.6 times the current sent through industry-leading Tesla Supercharger cables. The reason we can’t build these cables today is that moving that much electricity generates a lot of heat.
Some of that heat can be dissipated naturally by just making the cable thicker. But to move so much current with today’s technologies would necessitate a relatively inflexible cable that’s so wide in diameter—and so weighed down with pricey copper—that many people would have difficulty plugging it into their cars.
“For anyone with a disability, or older people with limited mobility, it would be more and more challenging,” notes Michael Degner, senior technical leader at Ford Research and Advanced Engineering.
But the Ford/Purdue technology allows a high-current cable to be as small, or perhaps even smaller, than the cables we have today, while also moving far more electricity. How? The technique comes down to liquid cooling, which has already been used successfully in technologies like graphics cards and LED lamps.
The cable is wrapped up like a garden hose, with liquid running over the wire. As that liquid heats up, it evaporates within the cable itself. Due to the chemical coolant being used, the liquid turns into a vapor well before it reaches the scorching boiling point of water, which would burn your hands. As Degner explains, this technique works to cool the wiring, even at low temperatures, because the phase change between liquid and vapor still requires a large amount of (heat) energy to occur.
Ford estimates it will need about two more years to hone the technology for market. However, even if it does, a better cable alone won’t be enough to reach five-minute charge times. Ford’s batteries will also need to be updated to accept so much power so quickly, because today’s batteries are their own bottleneck to faster charging speeds. Degner says Ford is on it, noting, “We’re working on many things in parallel.”