More info required, what generation/size is it?
did the connector break off the logic board or wire break in the connector?
Measure the open circuit voltage on the battery directly with a volt or multimeter ,nominal voltage for most i pod batteries is 3.7 volts
if you find the volts are lower than 3.0v its flat or defective
if its lower than 1.0v consider the battery needs to be replaced
although ifixit currently dont list these batteries ,they are widely available on major auction sites