PEREGRINE external battery pan oil heaters have been designed to maintain the battery temperature at a level to allow the battery to operate efficiently. They are generally used in ambient temperatures below -10°C and have an internal thermal cut-out set at 40°C for safety. They can be fitted in multiples as necessary depending on the size of the battery tray and number of batteries involved.

External battery pan oil heaters are ideally controlled by a separate air thermostat fitted to a nearby panel.