What if the battery and EV worlds have been barking up the wrong forest? What if, instead of forever seeking new battery chemistries and better materials for anodes and cathodes to improve energy density and battery range, we just needed a newer, better, smarter charging system?
GBatteries Energy, a tiny startup out of Canada’s capital city of Ottawa, claims it has a charger that can purportedly pump 119 miles of range (a half-charge) into a Chevrolet Bolt EV battery in 5 minutes and fill it completely in about double that time. Do we need fuel cells (or gasoline vehicles) if we can recharge an EV during a potty stop?
The technology originated as a basement-lab project for the self-described nerdy father-son team of Nick and Tim Sherstyuk. They were looking to extend the pitiful battery life of phones, not to shorten recharging time, by radically altering the charging process. Photos of MotorTrend’s long-term 2017 Chevrolet Volt are shown here.
Today’s lithium-ion chargers start out pumping electrons into a discharged battery at whatever level the plugs or circuit breakers allow. Then when the battery voltage rises to a maximum safe level, the current tapers off, maintaining that constant voltage. This constant-current, constant-voltage (CCCV) approach causes some lithium ions to crash into each other—especially during high-power fast-charging—while hurrying from the anode to the cathode. When this happens, those ions are no longer useful. These crashes kill the battery life.
Chief commercial officer Tim Sherstyuk describes the process of getting the charged lithium ions safely onto the cathode as akin to sifting rice through a screen. Force it, and some of the rice grains break the mesh. GBatteries pulses the current to “jiggle the screen” and occasionally reverses the current momentarily—like knocking the screen from the bottom to unclog it. This gets the ions through more safely and also more quickly.
Some Googling will turn up lots of academic studies of pulsed charging, but GBatteries’ secret is in the adaptive nature of the pulsing frequency, which constantly pulses parameters like amplitude, width, and periodicity, interspersing discharge cycles as necessary. Artificial intelligence programmed into the controller monitors the battery’s dynamic impedance, or resistance to current flow, tailoring the pulse rate to minimize impedance, reducing battery temperature and preventing those irreversible battery-life-killing “ion wrecks.”
In lab tests, fast-charging batteries from 25 to 95 percent charge using both methods, GBatteries found that after 17 recharges the useful capacity of the CCCV-charged batteries dropped to about 83 percent of original, while the pulsed batteries retained more than 85 percent of their capacity after 110 cycles.
A few caveats. Those tests were on smaller batteries, and so far the aforementioned impressive Bolt EV charging stats come from computer modeling. A prototype EV charger should be running later this year. Note also that physics demands that hitting 50 percent in 5 minutes requires a charging rate in kW that’s five times the battery’s capacity in kW-hr (300-kW charging of a 60-kW-hr battery).
The minimal hardware (a power filter to create the wave form) and extensive software that enables GBatteries’ pulsed charging could be integrated into the vehicle (and the company is talking to multiple OEMs). But the quicker path to market will be integrating it onto the DC fast chargers and getting OEMs to push software updates that enable their vehicles to accept the new charging protocol. It’s expected to work with all currently available EV battery chemistries.
Imagine charging stations transitioning away from parking-place devices used by a handful of vehicles per day to yet another choice on the filling-station island, frequented by hundreds of vehicles a day. These vastly more profitable chargers will proliferate naturally, allowing EV batteries to shrink without causing range anxiety, because drivers can conveniently “gas up” like they do today when taking longer trips.
I feel an “inflection point” in EV sales coming if this works out. And it’s sure to kill all demand for hydrogen fuel cells—that infrastructure just doesn’t seem to be happening.
Read more by Frank Markus here:
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