Long-term storage of nickel-cadmium batteries often results in a low liquid level because what happens to the electrolyte?

• A. Evaporation of electrolyte
• B. Contamination by moisture
• C. Electrolyte becomes absorbed into plates
• D. Leakage through seals

Answer: (C)

Long-term storage lowers the visible liquid level because the electrolyte is drawn into the porous electrode plates. In nickel-cadmium cells, the potassium hydroxide electrolyte fills not only the space between plates but also the pores of the active electrode materials. Over time, capillary action and diffusion pull some of this electrolyte into the plate structures, so the external level appears reduced even though the total electrolyte isn’t lost. This isn’t due to evaporation, leakage, or contamination—it's simply absorption into the plates.