Circuits and methods for cell number detection

A monitoring system comprising:

• a detection circuit selectively coupled to a battery pack and capable of detecting that said battery pack comprises N battery cells, wherein said detection circuit comprises:
• a plurality of nodes comprising M nodes selectively coupled to said N battery cells, wherein M is a positive integer and N=1, 2 . . . M−1;
• a detection block coupled to said nodes and configured to receive a terminal voltage at a first node in said nodes;
• and
• a controller coupled to said detection block and configured to control a connection to said first node such that said terminal voltage at said first node is at a first level if there is a battery cell in said N battery cells corresponding and coupled to said first node and such that said terminal voltage is at a second level different from said first level if there is not a battery cell corresponding to said first node, and said controller further configured to determine whether said battery cell corresponding and coupled to said first node is present according to a comparison between said terminal voltage and a first reference, and configured to generate a cell count signal indicative of said cell number N according to the determining;
• a plurality of cell monitors comprising M cell monitors, wherein each of said cell monitors is configured to monitor a battery cell;
• and
• a switching circuit coupled to said detection circuit and operable for enabling N cell monitors of said plurality of cell monitors and coupling the enabled N cell monitors to said N battery cells respectively.

A method for determining the number of cells in a plurality of battery cells, said method comprising:

• receiving a terminal voltage at a first node in a plurality of nodes, said nodes selectively coupled to said battery cells;
• controlling a connection to said first node such that said terminal voltage at said first node is at a first level if there is a battery cell in said battery cells corresponding and coupled to said first node and such that said terminal voltage is at a second level different from said first level if there is not a battery cell corresponding to said first node;
• determining whether said battery cell corresponding and coupled to said first node is present based on comparison between said terminal voltage and a first reference;
• and
• generating a cell count signal indicative of said number of cells based on said determining.