Varta R-series nickel cadmium (NiCd) batteries include the RL (long duration), the RM (medium duration) and the RH (short duration) batteries. The batteries operate over a temperature range of -40 to 50 degrees C (-40 to 122 degrees F), and are designed to be especially effective at low temperatures and deep discharge applications. Varta NiCd batteries are housed in translucent plastic cases to make their electrolyte levels visible for easy maintenance, and they feature a large electrolyte reserve to increase the time between maintenance intervals. The Varta RL line is specifically designed for low rates of discharge over long periods of time, making them suitable for use in emergency lighting, rail signal and ENS-A-6835 communication, telecommunications, photovoltaic, marine and alarm system applications. With a capacity range of 11 Ah to 1,500 Ah, the RL line covers backup times of one hour to more than 100 hours.