Studying Battery Range and Range Anxiety for Electric Vehicles based on Real Travel Demands

Determination of appropriate battery ranges is critical for developing and utilizing electric cars, which remains an active research topic. In particular, the issues of range anxiety have not been well studied concerning the battery design. Towards these research gaps, this study firstly investigates the baseline battery ranges based on the actual travel data collected from a large-scale longitudinal naturalistic driving study in the Midwestern USA. The occurrences and severity levels of range anxiety are then studied given the baseline, which leads to an augmented optimization model to eliminate such issues. Results show that in the baseline model, 60% of drivers can replace their gas cars entirely with 400-mile battery ranges, and less than 40% can do so with 200-mile battery ranges. Even when all the travel needs are satisfied, the optimal battery ranges can still cause range anxiety issues for all the drivers. An additional 25 miles of battery range can help solve the problem based on the improved optimization results.

713 Sleep of infants and toddlers during 12 months of the COVID-19 pandemic

Introduction SARS-CoV-2 changed the lives of children and their parents in 2020. To our knowledge, no studies have examined infant and toddler sleep during this pandemic. We sought to compare parent-reported sleep characteristics of infants and toddlers over successive quarters of the past year. Methods Parents of children aged 0–36 months were surveyed primarily in the Midwestern USA between 01/17/2020 and 12/07/2020. Each parent responded only once. Age was categorized as: <6 months, 6–12 months, 12–24 months, and 24–36 months. Income was categorized as: <$50,000, $50-100,000, $100-150,000, and >$150,000. The year was divided into quarters. Multivariable linear regression included Total Sleep Time (TST), Sleep Onset Latency (SOL) and parental frustration with sleep (any frustration, scale of 1–5) as dependent variables and year quarter, child’s age, prematurity, child’s comorbidities, maternal age (during their child’s birth), parenting experience, household income, and room sharing as independent variables. Logistic regression included nap consistency (napping at the same time daily) as the dependent variable, and year quarter, child’s age, prematurity, comorbidity, maternal age, parenting experience, household income, and room sharing as independent variables. Results Of 594 children, mean age was 18.5±9.7 months and 52% were female. Prematurity and comorbidities were reported for 8% and 15%, respectively. Mean maternal age was 31.8±4.5 years. Neither TST (β=-0.488; p= 0.16) nor SOL (β= 0.029; p=0.23) were associated with year quarter. SOL was 3 minutes less for each increase in income category (β =-0.051; p= 0.003). TST (β = -0.994; p<0.001) and SOL (β =0.092; p<0.0001) were most associated with child’s age. Parental frustration was associated with child’s age (β=0.12; p= 0.04), comorbidity (β=0.30; p=0.05) and room sharing (β= -0.38; p=0.006), but not year quarter. Nap consistency was associated with increased child age category (OR 1.47; 95% CI 1.13, 1.94) and lack of room sharing (OR=2.09; 1.10, 3.97), but not year quarter. Conclusion Parent-estimated TST, nap consistency and sleep-related frustration did not differ significantly over the first 12 months of the pandemic. Yet, our results underscore that special attention should be given to the sleep of infants and toddlers with comorbidities, who share a room, and who have a lower household income. Support (if any) 2T32HL110952-06