Sentry-6002NiCad

High quality vented Ni-Cad batteries in standby stationary applications can last for 20+ years, but they need proper maintenance in order to prolong the battery service life and optimize DC system performance. Without monitoring, inspections and maintenance can be scheduled on a calendar basis. However, manual verification of a large number of cells is time consuming and unreliable, especially for terminal connection resistance and inter-cell connection resistance measurements. Effective monitoring provides remote indications of abnormal operation and cell condition, including battery bus voltage, charging current, string continuity, temperature, electrolyte level, cell voltage, and corrosion caused by potassium carbonate (gray-white deposits) buildup. Effective monitoring also automatically records the discharge performance and facilitates scheduled capacity testing.

Giving the nature of pocket plate NiCad batteries, the aging and deterioration mechanisms are distinctly different from Lead Acid. A NiCad cell does not experience continual corrosion of the positive plate and grid structure throughout its operation life. Only the gradual aging or the active materials influences the service life. Degradation is primarily due to recrystallization of the nickel hydroxide in the positive plate. This aging contributes to a small portion of Internal Resistance so the Internal Resistance for NiCad cells remains steady over service life. 1-wire Mode Resistance reflects Cell Internal Resistance, Cell-to-Cell Connection Resistance and Electrolyte Low Abnormality.