Sealed Nickel-Cadmium Batteries for Aircraft-Electrical Systems

Vented secondary-storage batteries supply reserve electrical power to operate certain, essential aircraft equipment if primary power is not available. These vented batteries, however, are prone to premature failure. Spewed electrolyte and expelled hydrogen gas promoted by malmaintenance such as overfilling and underfilling the cells and by improper voltage regulation during charging lead to battery and equipment damage and failure and result in flight safety hazards and economic losses. Sealed batteries show promise of avoiding the shortcomings and maintenance aspects of the vented batteries. This paper concerns the efforts of the Air Force to apply sealed-battery technology to aircraft battery power needs.