d_batt 21[mm] "Battery diameter"
r_batt d_batt/2 "Battery radius"
h_batt 70[mm] "Battery height"
h_term 1[mm] "Terminal thickness"
r_term 3[mm] "Terminal radius"
d_sc 2[mm] "Serial connector depth"
h_sc 1[mm] "Serial connector height"
h_pc 0.5[mm] "Parallel connector height"
w_pc 1[mm] "Parallel connector width"