Mini E - Field Trial Program - Field Test Results

Field Test Results

The main concerns reported by some of the users participating in the U.S. during the first year trial were range anxiety and lack of public charging infrastructure, as the country had only 734 public charging stations, and most of them were located in California. Another concern reported is that the already restrictive 100-mile (160 km) range on a fully charged battery reduces to between 80 to 90 miles (140 km) during very cold weather. In the UK, an abnormally harsh winter also showed how very low temperatures diminishes power output until the battery is ‘warmed-up’ once in use. There was even one report of the range dropping below 40 miles (64 km) in sub-zero weather. There have also been issues with exterior charging points as winter temperatures drop dramatically.

Other complaints in the U.S. related to the lack of space in the car as the battery pack eliminates the Mini’s back seat and most of its cargo area, and the difficulties found in practice to install the charging equipment in homes, which took longer than anticipated, as just getting the installation permit in the U.S., including site visits and inspections took up to a month.

BMW

According to the BMW team of engineers responsible for the demonstration program, the following are facts and key lessons learned during the Mini E first year trial:

• Most of the Mini E applicants were well-educated and well-off males over 35, with an affinity for new technology, willing to experience a new and clean technology, and for them the lower vehicle running costs were not very important.
• Most drivers used the Mini E as a second vehicle and for the daily commute.
• Longest trip in a Mini E to date was 158 kilometres (98 mi)
• In the Berlin trial, the average Mini E remained stationary for over five hours in 80 percent of the cases while being charged and most of the customers only charged their vehicles only two or three times a week. U.S. participants were more likely to charge up every night.
• Before the test, drivers said they expected range and charging time limitations to be a problem, however, during the actual trials these issues were only felt to be limitations in very few specific cases.
• In the Berlin test, BMW decided to compare how people drive an electric car to how they drive a more traditional model. For this purpose they identified willing applicants who had either a BMW 116i or a Mini Cooper and put data loggers in those vehicles. The results showed that vehicle usage of the Mini E only differs marginally from that of comparable Mini Cooper and BMW 116i trips.

UC Davis study

In May 2011 the Plug‐in Hybrid & Electric Vehicle (PH&EV) Research Center at the University of California, Davis published the results of a consumer study of the U.S. Mini E field trial. The study is based on surveys and interviews conducted with more than 120 families who leased the electric car for the period of June 2009 to June 2010. Some of the key findings of the consumer study are the following:

• 95% of the respondents drove fewer than 80 miles (130 km) a day; and 71% drove fewer than 40 miles (64 km).
• The study shows that households adapted their driving around the capabilities of the electric car, and respondents said the MINI E met 90% of their daily driving needs.
• Many drivers found that having limited cargo space and only two seats was more restrictive than the limited range.
• Cold weather had a significant impact on drivers in the New York and New Jersey areas, which suffered a particularly harsh winter during the study period. These drivers discovered an unacceptable drop in the vehicles' range when using the heater.
• In California, though infrequent, hot weather during August 2009 resulted in range loss and battery thermal management problems that required attention from BMW.
• Most drivers reported initial difficulties in mastering the MINI E aggressive regenerative braking system which is integrated into the accelerator pedal. However, all drivers said that once they learned to like the system, they discovered that they could travel more smoothly, and learned to control almost all acceleration and braking events with one pedal. They also discovered, thanks to the display panel information, that they recovered energy proportional to their expertise with the single pedal.
• 99% of respondents found home charging easy to use.
• 71% of respondents said they were more likely now to purchase an electric vehicle than they were a year ago, and only 9% said they are less likely.
• 88% of respondents said they are interested in buying a battery electric vehicle or plug-in hybrid electric vehicle in the next five years.

Oxford Brookes University

In August 2011 BMW published the results of the UK trials. The findings are based on the 40 test cars driven by 62 members of the public and 76 pool users, who together drove 258,105 miles (415,380 km) over two six-month periods. The data was collected electronically and the research was carried out by Oxford Brookes University. The following are some of the main findings:

• The Mini Es logged a daily journey distance of 29.7 miles (47.8 km), slightly more than the 26.5 miles (42.6 km) recorded by the control cars, a mix of Mini Coopers and BMW 116i models. The UK average daily distance driven for private cars overall is less than 25 miles (40 km).
• The average cost to charge over 6 months was GB£60, representing less than 2 pence per mile.
• Drivers did not charge their Mini E every night. The average was 2.9 times a week. Most charged at home, with 82% using their wall-mounted charging box 90% of the time.
• Four out of five people reported that 80% of their trips could be done exclusively in the Mini E, and this increased to 90% saying that with the addition of rear seats and a bigger boot, all their trips could have been done in the Mini E.
• 84% of the drivers said that the severe low temperatures during both phases of the field trial affected the distance that could be driven between charges, but despite that, four out of five participants told the researchers they thought the Mini E was suitable for winter use.
• When asked for suggestions to deal with the potential danger from the low noise at low speeds, more than half (56%) said that instead of an artificial noise, the driver should pay more attention. However just over a quarter (28%) said they’d like to have a warning noise below 12.5 miles per hour (20.1 km/h).
• The trial found that one week was all that was needed for customers to adapt to the characteristics and peculiarities of driving an EV, such as charging, range, regenerative braking and low noise.
• For fleet users who swapped out of their regular car reported that the Mini E was fine for 70% of journeys made during the working day, while the pool car success rate was even better with between 80-90% of regular trips achievable