Impact of Traffic Load Cycles on Urban Battery Litter

Recent studies have demonstrated that the annual rates of consumer battery litter on urban pavements can be as high as 215 batteries per hectare of pavement and 0.4 batteries per meter of curb. As littered batteries deteriorate, they release components of potential environmental significance (Ag, Ba, Cd, Cr, Cu, Hg, Li, Mn, Na, Ni, Pb, Ti, Zn) and add to urban storm water contamination. However, consumer batteries come in many sizes, brands, and power chemistries, all of which may deteriorate at different rates in response to hostile physical and chemical conditions. The work presented here examines the impact of tire load cycles on battery litter. Tests were conducted on 735 individual cells representing 42 brands of AAA, AA, C, and D cell batteries. Results indicate that there are significant differences in the deterioration properties of battery brands and power chemistry types. Alkaline batteries are most resistant to deformation under tire loading. Nearly 50% survive their first tire load and about 30% survive 100 tire load cycles without rupturing. Zinc chloride/zinc carbon (ZnCl/ZnC) batteries are less resistant to deformation. Only approximately 10% survive their first load cycle unruptured. Cell size appears to have little influence on traffic-induced rupture. Based on general battery litter profiles, mass loading calculations for moderate traffic areas should assume that 70% of littered cells have experienced rupture release. This estimate should be increased to 85% for heavy traffic areas. These estimates may be refined if more detail is available on the brand and type distribution of site battery litter.