Recent measurements highlight the importance of battery-aware evaluation of energy efficiency in wireless sensor networks. However, existing battery models been not investigated in the context of the low duty cycle, short duration loads that are typical of sensor networks. We evaluate three battery models with regard to their applicability in the WSN context. Our evaluation focuses on how the models reflect two key battery discharge behaviors, the rate capacity effect and charge recovery. We find that the models handle the former better than the latter and are more sensitive to a load's peak current than to its timing.