Onboard devices such as sensors or communication and weapon systems require a continuous power supply. For keeping the batteries charged, usually the engine has to be started. This will create noise and emissions, considerable fuel consumption and may result in a loss of camouflage.
Power demand: 80 W to 300 W peak
For reliable availability of on-board devices in standby mode, an additional power supply is needed, e.g. in vehicles at command post. Batteries as sole energy source will not be sufficient: Due to their limited runtime batteries (24 V @ 45/100 Ah) will soon be discharged. To avoid running out of power, many vehicles today use up to six batteries per vehicle per year. Military generators, which up to now were used for recharging the batteries, are very heavy and generate visible emissions, detectable odors and heat. A generator consumes up to one liter diesel per hour, resulting in an essential requirement for fuel that must be carried along or logistically provided, limiting mobility. Solar panels are often inconvenient and, as sole energy supply, weather dependant and unreliable. If the idling engine is used for recharging the batteries, various engine and gear box parts will be subject to extreme stress and wear from the idle mode – mostly in cold stand. That causes higher maintenance efforts and costs.