In brief: Electronic bicycles have grown in popularity as emissions-free alternatives to mopeds and motorcycles, but charging them can be dangerous. The last two years have seen a dramatic rise in fires and injuries from exploding e-bike batteries in New York City.

The New York City Fire Department reports that as of last week, it has investigated significantly more fires caused by e-bike batteries than in all of 2021. City authorities have proposed multiple solutions, including regulations and partial bans.

Electric bike batteries have caused a suspected 174 fires in NYC in 2022. That's an average of about four per week. By the end of the year, that number may hit double last year's total of 104 and quadruple the 44 reported in 2020. Battery-related fires in 2022 have already injured 93 and killed six New Yorkers, compared to last year's 79 injuries and deaths.

The problem lies between the bikes' lithium-ion batteries and their chargers, which aren't universally inter-compatible. If a rider uses a charger with the wrong power level, it may overheat the battery after it's fully charged, risking a fire. Flammable material can also leak out of the cells and ignite.

Furthermore, users often opt for refurbished batteries that pose a higher risk. Many e-bike riders are couriers and delivery workers for whom new batteries are prohibitively expensive. Firefighters also find it challenging to identify which batteries and chargers are unsafe because fires usually leave them destroyed beyond recognition.

Another danger is that batteries, especially refurbished ones, can take hours to charge. Users can't keep watch through the entire process and may leave them plugged in overnight. Some restaurants might store the e-bikes on-premises, but freelance Door Dash or Uber Eats couriers have little choice but to pack them into dense apartments.

One new proposal will try to prohibit used power packs altogether, while another would require more stringent national testing standards for batteries. The New York City Housing Authority tried banning e-bikes and batteries from thousands of buildings earlier this year. However, it failed after intense resistance from delivery workers and officials.

Earlier this month, New York mayor Eric Adams announced a $1 million program to provide hubs for freelance delivery workers, which include charging stations. Still, it's unclear if they will allow overnight charging.