Accelerated Test Program.

This accelerated test was designed statistically using eight factors five environmental ans three physical previously identified as important to the battery performance at five levels of stress for each factor. Using these parameters, a full factorial design of 58 would require 390,625 test points. To keep the number of test points required to a minimum while obtaining the desired information on the eight factors and five levels of each factor, a composite design concept was used. this design consists of three statistical elements identified by the terms, fractional factorial, star points and center point. Table II-1 summarizes the eight factors and associated levels in the accelerated test program. The fractional factorial 1.4 of 28 functional evaluates the eight test parameters at a high and low level levels 2 and 4 of Table II-1 to determine which main effects and two-way interactions that have a significant effect on cell life. The star points of the design take each extreme level levels 1 and 5 of Table IV-1 of each factor in combination with the center level level 3 of Table IV-1 of the remaining severn factors.