When Manny Ramirez and his wife, Jessica Choque, come home after a long food-delivery shift to the Bronx two-bedroom they share with their five kids, they check their e-bike batteries. They wipe off any rain, ice, and mud. They comb every inch of the metal casing for new dents or scars — anything that could compromise the high-powered cells inside. Then they charge the batteries in the kitchen inside a bin Ramirez lined with aluminum foil in case the batteries should ignite while they’re asleep.
Ramirez and Choque are well aware that the threat of a battery fire is real. The amount of chemical energy in each lithium-ion battery — enough to keep a deliverista moving for six or seven hours — has the raw materials to start a life-threatening blaze. In New York City, this has been…