Expressed as the “C-rate” (named after Charles-Augustin de Coloumb), a 1C battery system takes one hour to discharge is fully rated charge. But unlike horsepower, the C-rate also determines how quickly a battery can be recharged, another bugbear for electric vehicles.
The same 1C battery takes one hour to fully recharge as well. Energy density refers to the total amount of potential energy stored per unit of battery mass.
This is an analogue to the traditional motorcycle fuel tank, but with an additional twist. An empty fuel tank is simply refilled but batteries suffer when deeply cycled many times. If you can prevent a battery from completely discharging by providing plenty of energy in reserve, the battery lifespan is dramatically extended.
While lithium NMC serves extremely well, Askenazi says he knows that battery power has some major hurdles to cross before internal combustion engines (ICE) have to fear the plug-ins. However, he is confident that battery technology will rise to the challenge soon.
“2C recharging cells are coming, probably one to two years out,” he states. “They’ll take a full charge in 30 minutes. Battery range is increasing five to ten percent year over year. Within the next five years, a disruptive technology will change everything.”
For Askenazi, electric vehicles face more subtle challenges than range and charging times. He explains that infrastructure and unit costs will hold EVs back compared to ICE machines. He explains how two different charging infrastructures have been created, further muddying the waters for nascent EV buyers. SAE J1772 and CHAdeMO are two similar but different systems that both offer rapid DC charging to EVs.
“But it’s like VHS versus Beta, HDDVD versus BlueRay,” Askenazi says. “EV companies need to decide which system they want to use and basically are placing their bets on that system becoming the common standard. But the good news is that at some point the costs for battery tech will lower the comparative costs.”
So what does the future hold? According to EV industry leaders like Tesla’s Elon Musk, the future of batteries isn’t a battery at all, but rather solid-state supercapacitors. This technology would eliminate charge cycle wear and tear, allow discharge and charge C-rates several magnitudes higher than the best rates chemical batteries could ever achieve and weigh less than half the lightest lithium batteries.
Of course, despite some very public headline grabbers like EEStor’s EESU, this technology has remained vaporware and science fiction up to this point. Of course, rechargeable storage may progress to the point where hundreds of miles of range can be safely stored while still being able to provide hundreds of kilowatts of usable power and be recharged in less than 15 minutes.
Article originally appeared in the October 2012 issue of Dealernews.
