Abstract: An electronic battery sensor and a method for determining an internal resistance of a battery, including at least one first detector for detecting measured values, and a battery model for ascertaining the internal resistance. Each measured value includes simultaneous information concerning at least two corresponding measured variables, in particular battery current and battery voltage, and every two successive measured values represents a measuring pair. The battery sensor includes at least one selector which is configured for selecting from a specified number of measuring pairs at least one measuring pair as a selection pair, and for providing the selection pair to the battery model in order to ascertain the internal resistance, the number of measuring pairs being greater than the number of selection pairs.

Abstract: An electronic battery sensor and a method for determining an internal resistance of a battery, including at least one first detector for detecting measured values, and a battery model for ascertaining the internal resistance. Each measured value includes simultaneous information concerning at least two corresponding measured variables, in particular battery current and battery voltage, and every two successive measured values represents a measuring pair. The battery sensor includes at least one selector which is configured for selecting from a specified number of measuring pairs at least one measuring pair as a selection pair, and for providing the selection pair to the battery model in order to ascertain the internal resistance, the number of measuring pairs being greater than the number of selection pairs.

Abstract: The invention relates to a method for recognising a critical battery condition after a reset (200) of a battery monitoring device (100), wherein a data item indicating the critical battery condition is stored (221) in a non-volatile memory (121) when a critical battery condition is recognised (220) by the battery monitoring device (100), and after the reset (200) of the battery monitoring device (100) a critical battery condition is recognised (211, 220) if the data item indicating the critical battery condition is stored in the non-volatile memory (121).