As part of the LLEC energy demonstrators, two battery energy storage systems will be installed on the FZJ campus. These battery systems are quite different from each other in terms of storage capacity and power because this makes them more interesting for the LLEC science case. The first battery is a high-energy battery system with a capacity of 2600 kWh and a power of 595 kW. The second battery is a high-power system with a capacity of 500 kWh and a total power of 1500 kW. Note that kWh is actually a unit to express (electrical) energy consumption for which e.g. the energy company charges you every month some money. However, in this context, it is more common to speak about capacity. The difference between a high-energy and high-power battery is that a high-energy battery has a high number of kWh’s per unit of weight. High-energy batteries are, for example, typically found in battery electric vehicles and laptops to allow long-range driving and user time, whereas high-power batteries are often used in hybrid electric vehicles and mobile power tools to (shortly) boost an electric device with high power.