E-bikes are too hot, literally. With a rise in exploding batteries, here’s how startups are stepping in to keep deliveries safe.

• The market for e-bike delivery has grown dramatically in the past few years.
• However, more delivery drivers using these bikes has led to an increase in fires.
• Here’s how startups, delivery companies, and city governments are improving safety.

The recent explosion of delivery startups and e-bikes has resulted in a new type of boom: increasing battery fires.

Cities across the United States have seen a dramatic increase in the number of e-bikes on their streets in recent years, as couriers and commuters seek cheap, durable, and environmentally friendly modes of transportation.

However, the rise of e-bikes, particularly for use by delivery drivers in congested cities, has raised fire-safety concerns due to lax safety regulations, poor manufacturing quality, and improper battery charging and storage.

According to city data, the number of fires caused by e-bike and e-scooter batteries increased from 44 in 2020 to 220 in 2022 in New York City alone. The fires spread quickly and can be fatal: According to the city’s fire department, 13 people were killed in lithium-battery fires in New York during the first half of 2023.

Even as cities raise concerns about e-bike safety, the industry grows: Last year, e-bike imports to the United States surpassed 1.1 million, a good proxy for total bike sales because most are manufactured elsewhere, up from just over 800,000 the previous year. While delivery sales from apps like Uber Eats, Instacart, DoorDash, and Grubhub are down from their all-time highs, sales for delivery services increased 6% year on year in June, according to Bloomberg Second Measure market research.

The quandary presents opportunities for companies seeking to bring safer, more affordable e-bikes and batteries to market. A slew of new startups are tackling the issue in a variety of ways, from developing safer batteries to establishing bike-sharing cohorts to taking over storage and maintenance.

“There are so many companies right now offering bottom-of-the-barrel products that don’t meet any safety regulations,” said Ravindra Kempaiah, founder of Zen Electronics in Halifax, Nova Scotia, which manufactures e-bike batteries. “The real need in the e-bike space is that we need batteries that last a long time, are very safe to operate, and don’t cost an arm and a leg.”

Why are so many e-bikes exploding?

Because of the high demand for e-bikes, shoddy models and battery packs are flooding the market, according to fire-safety and battery experts. As manufacturers compete for lower prices, some are sacrificing battery quality, with disastrous results.

“There’s a lot of very, very poor-quality battery cells coming from mainland China,” said Michael Pecht, a mechanical engineering professor at the University of Maryland who has audited the country’s battery-making operations. “The cleanliness, quality controls, and everything else are just not up to par for batteries today,” he added, comparing some Chinese manufacturers to “a garage.”

Because of advancements in lithium-ion technology, battery cells can now store more energy than ever before. That’s great for not running out of juice on a long ride, but it also means an e-bike’s battery pack can hold a lot of energy, which can be dangerous if released in an uncontrolled manner, according to experts.

“People don’t recognize the hazards that larger batteries can present,” said Brian O’Connor, an engineer with the nonprofit National Fire Protection Association. “They’re frequently compared to a tank of propane gas or a bucket of gasoline.” You wouldn’t necessarily keep those items in your bedroom or right next to your apartment building’s only exit.”

Overcharging, modifying, or damaging a low-quality battery — whether the one that came with the bike or an aftermarket replacement — can be disastrous. When a battery cell shorts out and begins to overheat, it begins to fill a room with flammable gas, according to O’Connor. When those fumes come into contact with an ignition source — often the flaming battery — an entire room can ignite in the blink of an eye, he said, making battery-related fires far more ferocious and fast-moving than other types of blazes.

Government officials are taking notice. Following a string of fires, New York City passed laws in March restricting the sale of refurbished battery packs and prohibiting the sale of new e-bikes that have not been certified by UL Solutions, which develops safety standards. The US Consumer Product Safety Commission urged manufacturers of e-bikes, e-scooters, and similar products to adopt UL’s standards in December.

Startups are racing to solve the problem

Startups are attacking the problem from all sides, with some founders focusing on batteries themselves, developing models that charge more efficiently and are less prone to thermal runaway.

Zen Electronics and ZapBatt, both based in Carlsbad, California, are primarily focused on this solution: putting out fires with stronger, more efficient batteries.

“E-bike batteries are made up of a bunch of small batteries stacked together,” Charlie Welch, cofounder and CEO of ZapBatt, explained. “As they age and one battery inside begins to fail, the others begin to compensate**,** making it difficult to determine the overall health of the battery.”

Welch said that ZapBatt, which is taking preorders for its batteries and plans to ship them in 2024, is using a military-grade base for its battery, which is more durable than traditional battery materials. The startup is also incorporating machine-learning-powered software into the battery to detect when specific cells are overheating, allowing other cells to pick up the slack and regulate energy demand throughout the battery.

Other startups, such as NYC-based Joco, are developing e-bike-sharing networks that eliminate the need for delivery workers to own and charge batteries at home.

Customers are invited to pick up e-bikes at a Joco hub, work for several hours, and return the bikes to a designated charging station. The company was founded in April 2021 by two friends named Jonathan Cohen. Memberships range between $12 for six hours of riding and $65 per week.

A spokesperson for Grubhub told Insider that the startup launched a pilot rest area in partnership with Grubhub last month in New York City’s SoHo neighborhood, which has already seen 1,000 unique visitors. The hub provides a place for drivers to rest, use the restroom, get water, charge their phones, and exchange depleted batteries for fresh ones stored in fireproof cabinets.

The pilot is expected to be expanded by Grubhub and Joco.

“We’ve really built a community around last-mile deliveries,” said Jonathan A. Cohen.

Popwheels, for example, is developing safe batteries that are compatible with the e-bikes that delivery drivers already own. According to David Hammer, one of Popwheels’ cofounders, the company runs a battery-exchange program in which drivers pay a $50 monthly subscription fee for access to UL-certified charged batteries that are compatible with the most popular e-bike models.

“You cannot offer a solution that does not make economic sense for delivery workers,” Hammer said, explaining that “if you’re a delivery driver, there are systemic incentives to get the cheapest batteries.”

Hammer and his cofounder and CEO, Baruch Herzfeld, launched their battery-swap pilot at the start of this year, but they’ve already received a lot of interest from drivers. According to Hammer, they sold out of their allocation of batteries for exchange on the first day of the launch and have a waiting list for hundreds of batteries.

“By word of mouth, we’ve found something that delivery workers want,” he said.