Managing your source of power in motorsport is vital. It can make or break a driver’s race weekend. Guaranteed, the actual act of running out of fuel during a race is something that has not happened in Formula 1 for many years, but in a sport like battery-centred Formula E, managing the power source until the end of the race is still a learning curve for some of the championship’s brightest talents.
With a new generation of Formula E just months away, pre-season testing for season five getting underway in October, the innovative second gen car will incorporate a battery that will last the entire race distance. For the first four seasons of the all-electric championship the cars had a capacity to last half of the race distance, resulting in a tense and often highly-strategic mid-race car swap. The new battery, developed by McLaren Applied Technology, will see the top power output increase to 250 Kw/h (335bhp) and an additional 50 Kw/h available to drivers during qualifying sessions.
A change to the race day format has also been made ahead of season five. Formula E races have now been given a time limit, 45 minutes, plus one additional lap instead of the traditional set number of laps that had been seen in the championship up until the season four finale at New York in July. It is proposed that this is a provisional measure to make sure that the cars have enough energy to complete the races.
During the season four campaign, there were several cases of drivers who battled at the front of the field and simply ‘ran out of power’ just as they approached the end of the race. Some wilted across the finish line in a sorry state, whilst others sudden drop of speed resulted in on-track collisions. One driver who experienced the fall from grace during a race this year as a result of energy management was Jaguar Racing’s Mitch Evans during the Rome ePrix.
“I was very good on battery and then things turned pretty quickly,” Evans told katyfairman.com. “You are running high targets, the pace is higher, the coasting zones are shorter, it is very hard to overtake.” Battling for first on-track and managing his energy during several full course yellows proved a challenge for Evans, who used up a surge of energy to chase Felix Rosenqvist and Sam Bird for the race lead. When Rosenqvist retired from the front of the field due to a damaged suspension, Evans pushed to the limits to pass Bird.
“That was my chance but Bird defended well,” Evans continues reflecting on the race. “The laps were very high in consumption and that diminished any chance of getting a good result. There were things for me to learn but ultimately it had been a positive day but disappointed at the end. This will only make Jaguar Racing a stronger as a team in our approach if we come to this position again.”
The tight city street circuits that Formula E race on are designed for close and challenging racing, with street circuits being notorious for difficult overtaking possibilities. It is achievable however, with the drivers in Formula E keen to show that the sport is not just a parade of cars finishing the race in the place where they qualify – no, Formula E drivers like to race and race hard. It is this constant desire overtake wherever possible from the high calibre of drivers in the championship that not only makes Formula E one of the most entertaining forms of motorsport out there, but also with the aid of features like Fanboost, encourages overtaking and pushing the car and its battery to the limits. In fact, as race winner Jean-Eric Vergne crossed the chequered flag at the Sunday New York Season four finale all drivers in the top four found themselves on just 1% battery, with the rest of the top ten on 2% or 3% remaining energy.
It is the constant demand to manage your battery to total precision that has come as a new challenge for some drivers. For a large percentage of the Formula E field, their experience juggling tyre compound wear and fuel consumption in motorsports such as F1 will have provided a different challenge to that of a battery. As mentioned above, the inaugural Rome ePrix displayed a variation of battery management techniques. In the penultimate lap, Bird and Evans who lead the pack in first and second both battled on 17% battery with a third place Lucas di Grassi on 19% and Andre Lotterer on an impressive 21%. It was with this extra energy compared to Evans that resulted in both di Grassi and Lotterer being able to overtake in aggressive moves that used up significant energy for podium positions in the final few laps. Evans fell to 9th place overall with Bird winning the race followed by di Grassi and Lotterer.
As one would expect, the temperature would also have an affect on the performance of a battery. Dry ice is often used to cool down the power unit after a session and battery thermal management is a key part of the inner engineering of the cars. Materials such as nickel and lithium may contain a high energy density but due to issues with their temperature rising too high, can result in fires or exploding. Using other materials such as aluminium or cobalt could be the answer to the future of batteries and their cooling as well as additional add-ons such as cooling tubes to assist the battery. With McLaren Applied Technology constantly working and developing new batteries and technologies to be used in Formula E, it is clear that the ideas and inspirations that are being invested into Formula E will soon be injected into our electric road cars. Some teams may struggle with an overheating battery, which will also influence the technique needed to manage the battery during a race weekend.
With the second generation car and its new battery soon to be tested to its limits, it is clear that the challenges of managing a battery are a new skill to many of the drivers that enter Formula E. However, with an ever-changing environment and growing expectation of an all-electric future both in the automotive industry and in motorsport, will battery management soon become the norm? What are the possibilities with a battery? Could Formula E look at incorporating ‘smart’ race tracks with inductive charging running throughout the track, eliminating the need to ever stop to charge the battery? The possibilities are endless.