Onboard satellite batteries are used for short duration power requirements, such as from the time the satellite is launched until solar panels are deployed and operational. In addition, a battery is needed to supply all the power during periods of eclipse. Proper thermal design and management of a satellite battery is essential for its long life and better performance. The goal of the present work is to estimate thermal behavior of the Ni-Cd battery for a remotesensing satellite. After the definition of on-orbit battery temperature requirements, charge and discharge cycles are presented for assessment of heat generated by the Ni-Cd battery. A thermal model that simulates the battery module onboard the satellite during its nominal orbit is developed using I-DEAS TMG thermal analysis software. Transient temperature predictions have been obtained on the battery module for the two expected design orbit environments. Analysis results are used to help in the design of a passive thermal control system to maintain acceptable temperature ranges for the battery. Parametric studies are performed in an attempt to determine the optimum passive thermal control hardware. Comparing these results with thermal requirements and constraints of the battery module, the final thermal design is obtained. Nomenclature A = radiating surface area, m 2 C = thermal capacitance, W=K c = specific heat, J=kg K E = cell voltage, V E oc = cell open circuit voltage, V F = view factor, dimensionless I = cell current, A i = orbit inclination, degree K = conductive conductance, W=K k = thermal conductivity, W=m K m = mass, kg Q = heat generation rate, W q = incident heat flux, W=m 2 T = temperature, K t = time, s s = solar absorptance, dimensionless = beta angle t = integration time step, s S = declination of the sun, degree " = emittance, dimensionless = cell charge efficiency, dimensionless = density, kg=m 3 = Stephan-Boltzmann constant, W=m 2 K 4 = right ascension of the ascending node S = right ascension of the sun Subscripts i, j = ith and jth element n = current iteration value Superscripts A = albedo E = Earth S = solar
