Pratt & Whitney Rocketdyne (PWR) awarded a contract to GS Yuasa Lithium Power Inc. (GYLP) to provide lithium-ion (Li-ion) battery cells to be used on the International Space Station (ISS). PWR will integrate GS Yuasa Li-ion cells into batteries that will replace the nickel-hydrogen (Ni-H2) batteries that currently power the ISS Electrical Power System (EPS) during its eclipse mode. This battery replacement effort is part of an initiative to extend the operation and utilization of the ISS. GS Yuasa will supply its LSE134 Li-ion cell that has completed qualification testing for the ISS program. The LSE134 (134-A·h nameplate capacity) cell is a member of GS Yuasa's Generation III family of Li-ion cells for space and is ideally suited to the electrical, size, and mass requirements of this mission. It approximately triples the available energy storage on both a per mass and a per volume basis relative to the existing Ni-H2 battery and is capable of powering critical ISS systems well beyond the required 10-year service life.