Ni-CD batteries are easy polarized in nomarl way of charge, H2 will generate from the electrolyte under the normal charge of constant current and constant voltage.
And the O2 will penetrate and react with the Cathode electrode and then CdO be generated, and this will lead down the capacity efficiency of the electrode.
Charge then discharge is the common method used in pulse charge, i.e. charge for 5 senconds, then discharge for 1 second, thus the most oxygen generated during charge is reverted to electrolyte at pulse discharge. Not only the gasification quantity of inner electrolyte is limited, but also the old batteries which have been seriously polarize can recover to or approach to their primary capacities after using this method for 5-10 times.
