Abstract: In an electronic thermostat timer having a time-keeping switch and having a thermostat, having an optoelectronic display (6) arranged at the front side of the housing for the time of day, the switching times and the switching temperatures, having a manual, key-shaped input device (7) for the time of day, the switching times and the switching temperatures in a common housing (1), the housing (1) is provided with a quadratic cross section, particularly having the edge dimensions 60.times.60 mm. A cylindrical clockface dial (3) is provided at the front side (2) of the housing (1), the outer circumference of said cylindrical clockface dial partially projecting beyond the sides (17) of the housing (1). A thermostat module (5) that is covered by a housing cover (10) is arranged at the back side (4) of the housing (1).

Abstract: The method for determining the energy content value (EIW) of electrochemical energy stores (1) by measuring the terminal voltage (U.sub.KL) of an energy store (1) recognizes at least one reference value (BW) that is formed from a sum current (EI) flowing in the energy store (1) in a specific time unit (dt) and in a specific operating voltage range (BSB) and/or from reaction values of the energy store (1) such as the internal resistance, the inside temperature and the acid density; dependent on a defined terminal voltage (U.sub.KL) in the operating voltage range (BSB) and on a defined energy content value (EIW) in an energy content range (EIB), this reference value (BW) thereby represents a function value. The measured terminal voltage (U.sub.KL) referred to the function value (FW) corresponds to a specific energy content value (EIW) in the energy content range (EIB).