Mobile battery charging

Andrew Williams | 12 years ago

Many of us are used to that sinking feeling when our car runs out of petrol and we are forced to trudge along the roadside to fill up a jerry can at the nearest petrol station.  Although inconvenienced, most people caught out in this way know that fuel is at most only a few miles away – but what would happen if you were driving an electric car and the battery ran out?  Given the state of the charging infrastructure in many regions, some drivers could be left stranded with little choice but to arrange to be towed dozens of miles to the nearest charge point.  In an effort to combat this ‘range anxiety,’ a number of innovative new solutions have been proposed, which are now either at, or very near to, market.

‘Intelligent’ charging

In an effort to ensure that the San Diego region is ‘plug-in ready’ for significant numbers of electric vehicles, regional utility company San Diego Gas & Electric (SDG&E ) announced in August that it plans to use a mobile car charging device from Juice Technologies as part of a trial of plug-in electric cars in the region.

The device, which SDG&E says can fit inside a standard car boot, is being developed to provide customers with a convenient, cost-effective method to charge their vehicle during off peak hours to take advantage of reduced electric rates.  As part of the initiative, Columbus, Ohio-based Juice Technologies will supply its Plug Smart ‘intelligent charger,’ which will be used alongside technologies being developed by SDG&E to enable customers to charge their vehicle anywhere in SDG&E’s service territory and charge the usage to their SDG&E account.  Users will also be able to view data, such as the amount of kilowatt hours used and carbon emissions.

Earlier in the year, SDG&E announced it would collaborate with Nissan to help develop the market for zero emission electric vehicles and charging infrastructure in the San Diego region.  The city is one of five locations in the U.S. to set up a network of charging stations for about 1,000 Nissan Leaf sedans made available to consumers.  SDG&E is serving as the local San Diego coordinator to help assemble a critical mass of regional electric vehicle fleets that municipalities, universities, the military, the port, private fleets and others use daily.

The utility wants to use the charger to let consumers control charging and view their energy usage via the Web or a mobile phone when used with a smart meter, said Hal Snyder, vice president of customer solutions for SDG&E, in a recent statement.

Angel Car

Swiss company Nation-E has recently developed a mobile charging system for electric cars, which provides technology for charging the batteries of stranded electric vehicles at the roadside.

The company says that its ‘Angel Car’ system will help in making the large-scale introduction of electric cars a more realistic prospect without the need for massive investment in new infrastructure.  Under the system, based on the idea of a standard breakdown service, a big carrier with an over-size battery can recharge a stranded vehicle enough for it to make its own way to a nearby charging station.  The system can be installed on any standard service car or on a dedicated ‘Angel Car’ unit.

The Angel Car Mobile Service Unit is equipped with an on-board 230V charger that is capable of delivering 2-3kWh in less than 15 minutes to a vehicle with a flat battery, enabling up to 30km of additional range.

The communication between the two vehicles is facilitated through Nation-E’s battery management system, which can interrogate and examine the parameters and the verification permits of the car battery, and determine the quantity and intensity of energy that should be fast charged into it.  The unit is also equipped with a touch screen that enables the controlled flow of energy.

Mitsubishi Electric

A team at the Mitsubishi Electric Research Laboratories have proposed a series of portable charging stations, which it says could be used as a means of cutting the cost of building a charging infrastructure.

At their headquarters in Cambridge, Massachusetts, senior researcher Zafer Sahinoglu and his team have designed a system in which a high capacity battery – such as a big lithium ion or zinc-based cell – could be charged at a specified location at night, making use of cheaper off peak electricity.  Under the proposal, the roaming charging stations could then be loaded onto a truck, and transported to a location where the demand for recharging is greatest.  Electric vehicles could then pull up and charge just as they would at a conventional charging station.

According to Sahinoglu, the big advantage is cost.  The problem with current plans for charging stations, he says, is that they need to be built, just like gas stations do. Moreover, there is also the associated infrastructure for the each station, such as power hook-ups, which costs money – sometimes hundreds of thousands of dollars.

In addition, the most likely time people would use them is during the day, when the load on the local utility is at its highest and power prices go up. “We could buy the power at the cheapest rate during off peak hours, and still sell it during the day at a lower cost,” says Sahinoglu.  Charging up the batteries at night also evens the load on the utility.

An added benefit is that cars could also make use of an on-board sensor to wirelessly transmit information about battery charge level to a central location, which could tell a battery provider where the need for chargers is greatest.  The theory is that this would enable smarter deployment and mean that there is no need to send charging stations to places they aren’t needed.

The team predicts that just five mobile stations would be needed to cover 100 electric cars on a 60 mile stretch of highway.

GE WattStation

Although not strictly a mobile solution, GE has developed an innovative portable device that will allow drivers to charge their electric car from the comfort of their own home.  Unveiled at the beginning of this month, the GE WattStation EV charger is a residential version of the public charger announced in July.  It is designed to help accelerate the adoption of plug-in electric vehicles by significantly decreasing the time needed for vehicle charging and, using smart grid technology, allowing utility companies to manage the impact of electric vehicles on the local and regional grids.

To assist in the roll-out of the devices GE has also teamed up with online communications specialists ServiceMagic to provide a network of certified electricians for the installation of the residential WattStation in consumers’ homes.  In addition GE Capital, working with ServiceMagic, will provide financing options, enabling consumers to pay for the charger and installation costs over time.

Designed by industrial designer Yves Behar, the company claims that the WattStation decreases average electric vehicle charging time from 12-18 hours to as little as four to eight hours (when compared to standard charging ‘level 1,’ assuming a full-cycle charge for a 24 kWh battery).

Speaking about the new product Behar said, “Typically, if you need some power for your car, you need to drive around and find a gas station.  In this case, all you have to do is drive into your office garage or your house garage and just charge your car where you are.  It means simply that the power comes to us rather than having to go and look for it.”

The device will be available to the general public around the world sometime next year.  According to GE, the residential version is expected to cost somewhere between $1,000 (£630) and $1,500 (£950) per unit.

Power to the people?

Although unlikely to completely obviate the need for some form of in situ system, initiatives such as these could do much to promote the smoother introduction of an electric car charging infrastructure.  In particular, their relatively low cost may enable the rapid deployment of a workable, if small scale, system in regions that, for one reason or another are less eager to adopt larger networks.  As a result, they are likely to help in alleviating the range anxiety concerns of potential electric car drivers.

Perhaps more importantly, their adoption could also send a powerful, and very visible, signal to policy makers, manufacturers and charging providers that large scale infrastructure investments may not necessarily be the only means by which a transition from petroleum based transport can be achieved.

Rather, if employed alongside the more incremental establishment of ‘permanent’ charging stations, mobile and portable solutions may serve to change perceptions of the best means of achieving an important critical mass of users.   In doing so, they could provide a partial solution to the existing ‘chicken and egg’ situation, whereby drivers are reluctant to buy EVs because they can’t charge them, and few are prepared to invest in a charging infrastructure because not enough people drive electric cars.

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Andrew Williams'