"We have a lot of problems with different standards around the world already," says Josef Krammer, team leader for charging systems at BMW. "We deliver our vehicles everywhere, and it's very difficult if we have to adapt our charging systems for each region."
According to Krammer, although CHAdeMO works, its major drawback is that it requires a second charging port in addition to the 110- to 240-volt AC port—which drives up both space and cost requirements. In addition, SAE's Byk says that CHAdeMO uses an older communication standard not expected to work well with coming smart grid technologies. Also, it is less safe because instead of relying on the physical contact with the ground to shunt short circuits, it relies on a ground fault interrupt, which monitors the line for imbalanced loads and shuts it off if it senses a surge. It is like the difference between having an alternate pipe for the sewage to drain into (physically grounded) and having a way to shut off a burst sewage pipe (ground fault interrupt).
Gaining a competitive advantage
Even so, Nissan says that CHAdeMO meets the needs of electric car drivers now and into the future. "As of today, CHAdeMO is the only proved DC quick-charging system," says Hideaki Watanabe, corporate vice president, Nissan Motor Co. "We are working with our partners to deploy CHAdeMO throughout the world, and we didn't want to take a 'wait and see' approach. We wanted to be a proactive player and deploy fast charging solutions now."
The existence of multiple standards may not actually be a big deal, says Pike Research's Gartner. "The real losers are the carmakers who are waiting to provide fast-charging support while their Japanese competitors increase market share," he adds.
What effect will it have on adoption rates?
Gartner envisions a future where both standards exist as parallel options. "Because of its penetration rates CHAdeMO won't ever become obsolete," he says. "Just because SAE says they are making a global universal standard doesn't mean the Japanese manufacturers are going to switch." As Gartner sees it, manufacturers will want to take advantage of the infrastructure that is already in place. "If there are already hundreds of stations on the ground—soon to be thousands—why wouldn't a manufacturer choose that option?" he asks.
But BMW does not think this parallel-option scenario will work. "Over the long term, I don't think that multiple standards can co-exist in one region," Krammer says. He cites the need for uniformity between all vehicles and convenient consumer access as the major reasons for this. SAE's Byk agrees, and says that the convenience of universal plug format, coupled with the majority of manufacturers adopting it in the long term will likely force the market to move away from CHAdeMO.
Regardless of whether one DC fast-charging standard wins, in the short term the controversy is sure to cause some confusion in marketplace, although Gartner does not think it will have much of an effect on adoption of electric cars. "The typical consumer still can't distinguish between hybrids and electric cars," he says. "If that basic distinction is still missing, then the DC fast-charging issue is one that means very little in terms of market adoption rates of electric cars in general."