You’re only as good as your weakest link and in a series string of batteries, that could be a single cell. The answer of course is parallel string offering redundancy – or a piece of electronics that switches cells into parallel operation when one cell goes down.
And that’s exactly what German-based Automatic Storage Device (ASD) showed at Intersolar this week. They call it Pacadu (parallel automatic charge and discharge unit). ASD has developed a new electronic device that can be installed onto each individual battery cell. The innovation allows any number of cells to be combined in a storage system, irrespective of their size, manufacturer, storage technology or power output. ”We have succeeded in finding a solution that overcomes the technical problems caused by connecting battery cells in series. This marks a real revolution, not only for energy storage systems but for every single battery used around the world. The parallel connection of battery cells has so many advantages that in four years’ time the practice of connecting cells in series will have become a thing of the past,” explains Wolfram Walter, Managing Director of ASD.
Walter gave no indication of cost of the device or ease of retrofitting.
According to Walter, the system allows batteries to be gradually modernised by replacing cells at the end of their life cycle with cells using the latest technology. The new technique of connecting cells in parallel increases battery performance by preventing the losses in voltage seen in cells connected in series. With an efficiency value far exceeding 90%, Pacadu itself causes hardly any energy to be lost. Batteries fitted with the smart control system can be connected at any voltage level, be it 12V as seen on campsites, 36V as found in e-bikes or 600V as is customary with large-scale storage systems. ASD not only uses the smart cell control system in its own energy storage devices, but also sells the component separately.