The working temperature range specified was from -30°C to +40°C and we carried out exhaustive testing to build this requirement into the customer specific design. The Chargers also had to be IP rated as they would be subject to the extremes of weather throughout the European region from the Barents Sea to the Mediterranean. To meet this operational concern we developed a partial potting process for manufacturing to ensure compliance. The Chargers also had to be UV tolerant and suffer minimal degradation over an extended lifetime. Extensive testing to confirm compliance was carried out both in the FRIWO R&D area and at the customers own test facilities. Despite these high parameters, there were also very strict condensation limits imposed at most extreme operating conditions at the design stage.