Monday, October 14, 2019

Battery Management of E-bikeshare and E-scootershare

Recently, I attended an excellent presentation about battery management at the North American Bikeshare Association (NABSA) conference. With more electric bikeshare and scootershare vehicles hitting the streets around the world, this topic is of increasing importance. As an e-bike owner, I personally have seen how it has changed how I get around in the hilly Washington, D.C. region as I bike a lot more now than before I bought the e-bike. While these e-bikeshare and e-scootershare vehicles can be great and increase getting around town without needing drive or be driven; unless their rechargeable lithium-ion batteries are managed well during their useful life and recycled properly into steel, stainless steel, and new batteries; e-bikeshare and e-scootershare can cause more harm than good to our customers, staff, and the environment. As MetroBike manages e-bikeshare and e-scootershare systems for local governments, I took note.

E-bikeshare & e-scootershare parking corral
The reason lithium-ion batteries are so popular and omnipresent is because they can hold a lot of energy in a small package, called “energy density”. According to Battery University “The energy density of lithium-ion is typically twice that of the standard nickel-cadmium. … Most of today's mobile phones run on a single [lithium-ion] cell. A nickel-based pack would require three 1.2-volt cells.”
Lithium-ion batter (credit: B&H)
However, a major problem with lithium-ion batteries are that they, “have a tendency to overheat, and can be damaged at high voltages. In some cases this can lead to thermal runaway and combustion,” says the University of Washington’s Clean Energy Institute. Not being familiar with the term “thermal runaway”, I had to look it up. It’s defined by Lithium-Ion Battery Chemistries as, “when a cell has reached the temperature at which the temperature will continue to increase on its own and it becomes self-sustaining as it creates oxygen which feeds the fire (literally).”

Electronic bikeshare and scootershare vehicles already have been reported to have had multiple fires on the street and in warehouses in the U.S., such as the reported instances of e-bikeshare in Bicycling Magazine and e-scootershare in The Washington Post. I haven’t read any reports yet of fires happening while someone is on a vehicle and hope it never happens.

Capital Bikeshare Plus (credit BeyonDC)
The NABSA presentation that I mentioned above was given by Todd Ellis of Call2Recycle. He suggested e-bikeshare and e-scootershare operators and municipal system owners both have roles in battery management. Mr. Ellis stated:

Operators should:
-accept that this is an issue;
-size up the issue;
-select a storage area in their warehouse;
-develop standard operator procedures for battery management, including handling used, damaged, and defective batteries;
-train employees on handling; and
-plan for the worst.

How’s that for sobering?

In addition, municipalities should:
-have operators provide their battery management plan as a micro-mobility application requirement,
-require the operator provide their battery recycling partner contract, and
-include the cost of recycling batteries in abandoned vehicle fines.

This just scratches the surface.

E-bikeshare and e-scootershare vehicles are here to stay. Bikeshare has proven for over a decade that it’s successful at getting people around town in a healthy, fun, and environmentally friendly way. E-bikeshare bikes are generating roughly three times more trips than standard pedal bikeshare bikes because the electric version makes it easier to get around without exerting as much effort. E-scootershare didn’t have a non-electric shared version, so there’s no direct comparison. With the immense uptake of e-scootershare around the world, one can see that people like to get around without effort, and the easier, the better. E-scootershare requires even less exertion than e-bikeshare as pedaling is not involved.

E-bikeshare and e-scootershare will continue to evolve. With the popularity of these vehicles, likely there will be many more generations of electric vehicles and they’ll all need batteries. So the need for safe and environmentally friendly battery management will continue to grow.