Much research is being conducted into the potential value of residential energy storage. The temporal resolution of the analyses carried out in these studies is typically driven by the available data, which is often only at 30-minute or 1-hour intervals. This study uses higher temporal resolution data to examine the effect of input time-series resolution on the value determined for residential storage. In the case study considered, an analysis carried out at a 30-minute interval underestimates the cost-saving delivered by 5kWh of residential energy storage by 17% on average, compared to the same battery analyzed at a 1-minute interval. The sensitivity of storage value to temporal resolution is found to vary significantly from one customer to the next. A method for improving estimates of the realtime value of energy storage using coarser time-series data is introduced. Finally the impact of temporal resolution on storage technology selection is also evaluated.