Question

What may result if water is added to a nickel-cadmium battery when it is not fully charged?

A. Excessive electrolyte dilution.
B. Excessive spewing is likely to occur during the charging cycle.
C. No adverse effects since water may be added anytime.

Answer 1

Adding water to a nickel-cadmium (NiCad) battery when it is not fully charged may result in excessive electrolyte dilution, which can affect the battery's performance and reduce its capacity.

Step-by-step explanation:

Adding water to a nickel-cadmium (NiCad) battery when it is not fully charged may result in excessive electrolyte dilution. NiCad batteries contain a cadmium anode and a highly oxidized nickel cathode, and the overall reaction during discharge is Cd(s) + 2NiO(OH) (s) + 2H₂O(1) → Cd(OH)2(s) +2Ni(OH)2(s). The products of the discharge half-reactions are solids that adhere to the electrodes, and when the cell is recharged, the reaction is readily reversed. However, adding water to an already diluted battery can alter the concentration of the electrolyte, affecting the battery's performance and possibly reducing its capacity.