A detection device and method for accurately detecting the battery capacity remaining in the device independent of the operating mode of the device. Additionally, one or more mini-clusters are created in each of the super-clusters based on how close the point-of-interest locations within each super-cluster are to one another. Additionally, a plate-and-frame membrane module for direct contact membrane distillation using a multilayer mixed matrix membrane is provided. The refresh cycle includes clock cycles. The shaft sealing arrangement further includes an additional seal which seals the shaft in the region of the cooling ring in order to reduce the feed of hot fluid into the gap between the shaft and the cooling ring, with the additional seal being formed as a brush seal.