PARIS – Electric-vehicle recharging points in underground parking lots should be 15 m (46 ft.) apart, and cables furnished with cars that can plug into ordinary 230V sockets need to limit electric flow to 12 amps, meaning an average of 12 hours for a full recharge, the French ministry for the environment says in newly released EV safety recommendations.
A report on the history of fires and explosions involving lithium-ion batteries dated last fall but published June 20 concludes that “risk management of fires in confined areas is more delicate than in open areas” because discovery can be delayed, fires spread more easily and the thermal and chemical impacts are potentially more intense.
One of the accidents reviewed by the team from Ineris, the national institute for industrial risk environment, was at the SECMA minicar factory in France. A fire that started during the recharging of one vehicle in April 2009 spread quickly to others nearby, aided by the fact the body panels were plastic compositions.
While powerful batteries don’t contain as much energy as liquid fuels, the auto industry and governments have had 100 years to develop safety procedures. The Li-ion battery business is much younger. During 2006-2007, Sony, Sanyo and Matsushita paid at least $600 million to recall Li-ion batteries for portable computers that caused occasional fires, and the danger of a problem was 1 in 200,000.
The study of past accidents indicates lithium battery accidents have occurred where they are manufactured, as they are transported, as they are used and when they are recycled.
The Ministry of Ecology, Sustainable Development, Transport and Lodging remains optimistic about the potential of EVs, but wants to be sure they are used safely when they begin to arrive in volume next year in France.
“The deployment of electric vehicles and plug-in hybrids is an economic and environmental opportunity for France,” the ministry says. “Besides the advantage of the ecological footprint, the no-carbon vehicle represents a market valued between E20 billion and E50 billion ($30 billion-$70 billion) from 2020 in Europe (E7.5 billion [$10 billion] in France).
“The national plan for the development of this industry envisions having 2 million vehicles of this type on the road in 2020.”
A spokeswoman for Minister Nathalie Kosciusko-Morizet says the recommendations on recharging EVs have been shared with operators of parking facilities, auto makers and the electric industry. While they are for the moment recommendations, she says, “They will be imposed.”
Operators of underground parking facilities have four options:
- Limit recharging points to one per floor.
- Locate recharging points 15 m apart.
- Put sockets closer together but in a semi-confined space.
- Separate vehicles being recharged with fire-walls.
For private individuals, the ministry wants to limit accidents by restricting the recharging power unless the socket involved has been verified, suggesting:
- Charging at ordinary unverified sockets be limited to 12 amps.
- For a socket that has been inspected and verified, 13 amps would be permitted, for a 10-hour recharge.
- For a dedicated charging point with built-in safety features, which the EDF electric company has proposed to install for about E300 ($420), the charge could be at 16 amps, for an 8-hour average recharge.
Auto makers will be obliged to furnish recharging cables compatible with any socket in France and that have internal electronic controls that limit a recharge to 12 amps.
The ministry says its recommendations will allow people to prepare for the launch of large numbers of EVs, and that experience with real EVs will lead to a better understanding of the risks and the requirements for safety.
“Other steps will follow depending on the evolution of technology, what we learn and the need to adapt recommendations.”