Nickel cadmium batteries in defibrillators

This article describes the failure mechanisms of nickel cadmium batteries. The design of suitable battery chargers for defibrillators is discussed. It is argued that the life of nickel cadmium battery packs can be significantly extended without impairing safety if appropriate testing is carried out. Results of tests on a set of 10 defibrillator packs removed from service after a period of two years are presented.