Community energy storage (CES) has been proposed to mitigate the high variation in output from renewable sources and reduce peak load on the electrical grid. Thousands of these systems may be distributed around the grid to provide benefits to local distribution circuits and to the grid as a whole when aggregated. CES must be low cost to purchase and install and also largely maintenance free through more than 10 years of service life to be acceptable to most utilities.Achieving the required system life time is a major uncertainty for lithium-ion batteries. The lifetime and immediate system performance of batteries can change drastically with battery temperature, which is a strong function of system packaging, local climate, electrical duty cycle, and other factors. In other Li-ion applications, this problem is solved via air or liquid heating and cooling systems that may need occasional maintenance throughout their service life. CES requires a maintenance-free thermal management system providing protection from environmental conditions while rejecting heat from a moderate electrical duty cycle. Thus, the development of an effective, low-cost, zero-maintenance thermal management system poses a challenge critical to the success of CES. NREL and Southern California Edison have collaborated to evaluate the long-term effectiveness of various CES thermal configurations in multiple climates by building a model of CES based on collected test data, integrating it with an NREL-developed Li-ion degradation model, and applying CES electrical duty cycles and historic location-specific meteorological data to forecast battery thermal response and degradation through a 10-year service life.