Ambibox reports efficiency world record for solar DC charging of electric off-road buggy

Students at Bochum University have developed an off-road electric vehicle that can be charged with PV modules. And because the vehicle doesn’t belong on the A40 in the Ruhr, but rather in the desert, the students took a joyride in Australia: trying to cross the central Simpson Desert where the temperature at the time of writing was 45 degrees Celsius.

The SolarBuggy vehicle carries folding solar modules. Filling the battery requires special charging technology with a very high level of efficiency, small volume and low dead weight. The technology must achieve optimum efficiency in the desert under the most extreme conditions, must be dust proof and be able to be cooled via the housing without a fan even in hot temperatures.

Technology partner Ambibox, a start-up from Mainz, near Frankfurt am Main, modified its charge controller and adapted the power electronics for the brief. “The technology in the SolarBuggy corresponds to the future charging infrastructure for electric vehicles: highly efficient with high performance in a small space and based on DC voltage,” said managing director Manfred Przybilla.

Record attempt

The SolarBuggy team wanted to set a new record by crossing the Simpson Desert in less than four days and 21 hours but could not do so because the solar cells delivered 3 kW instead of the expected 5 kW, due to the unusually hot temperatures. Charging times were extended and when sand storms came along, the students jettisoned their record attempt.

But Ambibox was able to claim a landmark: The DC charging technology achieved an efficiency of more than 99%. According to the company, that was a level of performance unequalled anywhere in the world.

The charging technology of the same name makes it possible to connect various DC devices without detours via the AC network. It also regulates the energy flow of devices automatically. Depending on the application, said Ambibox, up to 20% of energy and expensive inverters could be saved by its technology since direct current no longer has to be converted into alternating current and vice versa.