STATE_OF_CHARGE
===============

Sensor or time series used for the storage state of charge. If ``soc-at-start`` is omitted, FlexMeasures will also use this field to infer the starting state of charge from a recent value near the schedule start. When a sensor is used, its unit may be an energy unit (e.g. MWh or kWh) or a percentage (%). For sensors with a % unit, the ``soc-max`` flex-model field must be set to a non-zero value to allow converting between the energy-based schedule and a percentage.