The morning sun is still low over the green as the elec­tric golf cart rolls silently away from the club­house. It shut­tles back and forth between tees and fair­ways on the sprawling course. However, its range is limited: By noon at the latest, the battery is empty and the cart has to be plugged into the charging station for several hours. This is a typical problem for small elec­tric vehi­cles.

The reason is simply the low energy density of the battery: Although it is small and light, it stores only a small amount of energy. In addi­tion, the battery cannot be charged as quickly as desired because it would other­wise over­heat. A larger battery does not solve the problem either: It only makes the vehicle heavier and thus more energy-hungry. Small, mobile appli­ca­tions there­fore need a different energy source that enables greater range, can be recharged more quickly and remains emis­sion-free.

The democ­ra­ti­za­tion of fuel cells

This is exactly where Spec­tronik comes in. The Singa­pore-based company special­izes in compact hydrogen fuel cells. The company’s stated goal is to further develop and democ­ra­tize a tech­nology that, due to its complex design, has so far been reserved for large appli­ca­tions such as trucks and buses.

With its Protium series, the company has managed to greatly compress the tech­nology. The result: a lot of energy in a small space with low weight. In addi­tion, the cells can be refu­eled in a few minutes and are completely emis­sion-free during oper­a­tion. Finally, when hydrogen reacts with oxygen, the only waste product besides energy is water. Spec­tronik is thus opening up the tech­nology to completely new appli­ca­tions for which hydrogen fuel cells were previ­ously too large or too heavy. However, compact­ness also brings new tech­nical chal­lenges.

Cool and fresh for full power

Fuel cells generate elec­tricity electrochemically—but not without losses. Around half of the energy released is waste heat. In addi­tion, mois­ture also enters the system with the reac­tion product. Without targeted thermal and air manage­ment, the cell is at risk of over­heating or “drowning.”

„We are making fuel cells more acces­sible and bringing them to all mobile appli­ca­tions.“

Spec­tronik

The cell always needs suffi­cient oxygen to perform well—especially when the vehicle is accel­er­ating. Previous solu­tions consisted of complex liquid cooling systems and compres­sors. While this is certainly a good solu­tion for trucks and buses, it is far too bulky and inef­fi­cient for smaller mobile appli­ca­tions. Spec­tronik has there­fore devel­oped an inno­v­a­tive system that regu­lates temper­a­ture and humidity even in confined spaces and supplies the fuel cell with fresh air.

To achieve these goals, two to six AxiForce 80 fans from ebm-papst are used. They reli­ably direct the warm, humid air outside and keep the fuel cell within the optimum temper­a­ture range. Two temper­a­ture sensors monitor the condi­tion of the cell and transmit the measured values to a control unit (MCU), which compares the actual temper­a­ture with the target temper­a­ture and regu­lates the speed of the fans via a PID controller—precisely and respon­sively with pulse width modu­la­tion (PWM).

AxiForce 80 compact fan

AxiForce 80 compact fan

RVE 45 radial blower

RVE 45 radial blower

Connec­tion

The Protium series has a modular design. A cell can be combined with addi­tional units as needed. This means that increased perfor­mance or range are no problem. (Photo | Spec­tronik)

The control unit distrib­utes the cooling capacity specif­i­cally to several fans. This means that no single fan has to run contin­u­ously at maximum power. This protects the compo­nents, increases service life and saves energy. An addi­tional advan­tage: Thanks to their DC motors, the fans operate partic­u­larly effi­ciently in the partial load range.

In addi­tion to the right temper­a­tures, oxygen supply is crucial. This is ensured by one or two RVE 45 radial fans from ebm-papst. They liter­ally allow the fuel cell to “breathe” by supplying fresh air from outside and dynam­i­cally adjusting the air flow according to power require­ments. This ensures that the cell always has enough oxygen for the reac­tion to produce suffi­cient energy, even during peak perfor­mance periods.

More power? More cells!

Spec­tronik fuel cells are compact, powerful and effi­cient. But what if the power of one cell is not enough to drive the entire vehicle? Spec­tronik has also thought of this scenario and designed its Protium series to be modular. This means that a cell not only works on its own, but can also be combined with other units as needed. More power or range are there­fore no problem. Cooling and oxygen supply are part of the modular concept and are perma­nently inte­grated into each unit.

Spec­tronik is thus initi­ating a revo­lu­tion in fuel cells. Mobile appli­ca­tions are gaining endurance—without heavy or complex battery systems. Drones can fly entire missions with ease instead of just short rounds. House­hold robots can work all day without having to be constantly recharged. And golf carts remain in contin­uous use instead of spending hours plugged into the power outlet. Where conven­tional batteries fail, hydrogen provides more power and range—efficiently, compactly and flex­ibly scal­able.