THE E-BIKE INDUSTRY WAS UNPREPARED FOR LITHIUM-ION BATTERIES. IT’S TIME TO ACT NOW.

By Mike Fritz

Lithium-ion batteries power our portable life.  Everything from cell phones and laptop computers to e-bikes and electric cars carry these batteries to power their function, no matter what they do.  Lithium-ion batteries power earth-moving equipment, forklifts, submarines, and prototype electric aircraft.  We are constantly learning about new applications and adaptations where portable electric energy is required to do work and achieve a function.

Why?  What makes this battery chemistry so popular for these numerous and diverse applications?  Simply put, energy density.  This chemistry enables the storage and delivery of significant amounts of energy (and therefore power) in a compact, lightweight form well suited to any number of applications.

This chemistry also manifests many other attributes that make it superior to other battery technologies.  Excellent cycle life, low self-discharge, long shelf life, rapid recharge and no memory-effect are the most important.

But there is a downside.  If the energy contained in a lithium-ion battery is released in an uncontrolled fashion, the results can, and oftentimes are, catastrophic.  Significant heat, aggressive fire, and copious quantities of extremely toxic gases are released.  These fires are incredibly hot and impossible to extinguish.  The best strategy for fighting a lithium-ion battery fire is to let the fire burn itself out.  The reactions present in a battery fire provide the oxidants necessary to sustain the fire until the fuel is exhausted.  You cannot ‘smother’ a lithium-ion battery fire with water, inert gas, sand, or other oxygen-depriving agents.  The more energy stored in the battery, the longer the fire will burn.  The net result is property damage, and unfortunately, sometimes severe personal injury and death.

There are numerous potential causes of the uncontrolled release of the energy stored in the battery.  Substandard materials, lack of production quality control, inadequate or improperly programmed battery management systems, or improper integration of the battery pack into the electrical system of its intended application can produce battery packs prone to failure.  Certain environmental conditions, excessive ambient heat, immersion in water, physical damage, and/or improper charging protocols can and do precipitate failure.

The good news is that properly manufactured batteries, tested and certified to applicable standards by competent certification agencies, when carefully integrated with the specific application for which they are designed, are safe and reliable for their intended purpose.  When users purchase certified products and are advised of the importance of proper care and maintenance, and how to recognize potentially compromised batteries, these amazing power supplies will provide excellent service for the duration of their useful lives.

E-bikes have been around for a long time, almost as long as bicycles themselves.  A U,S, patent for a battery-powered bicycle was issued in 1895.  But the ultimate utility of electric bicycles has always been constrained by the lack of a rechargeable, lightweight energy supply that could provide sufficient energy and power to enable useful performance in terms of range and torque.

Weight has always been an important attribute for bicycles.  Until recently, the most ubiquitous chemistry produced in a form factor that enabled adaptation to a bike was lead-acid battery chemistry.  As the name implies, lead-acid batteries are heavy.  Further, they manifest other undesirable characteristics, including very low energy density, low cycle life, high internal resistance, self-discharge, etc., that render them inappropriate for e-bike applications.  Nevertheless, they were the “only game in town.”

That is, until lithium-ion battery chemistry was successfully commercialized in 1991 by Sony.  Sony manufactures handheld electronics and laptop computers.  The high energy density, small size, and light weight offered by these early batteries represented a true breakthrough, enhancing the value of these products.  Users were able to enjoy long hours of continuous use without recharging their devices.

Lithium-ion power supplies were introduced on electric bikes in the late 1990s by EV Global Motors (EVG), Lee Iacocca’s nascent micromobility company.  I personally was involved with the project as Vice President of Engineering and Product Development at EVG.  Iacocca was convinced by a supplier that we could significantly improve the value, performance, and utility of our e-bike products by replacing the poor-performing lead-acid batteries we were using with lithium-ion battery packs.  And he was right.  The lightweight battery pack significantly reduced the weight of the e-bike, and the energy-dense battery pack resulted in much better range characteristics.

However, while energy dense, these batteries were not power dense.  Power is defined as the rate at which you consume energy.  These early lithium-ion batteries were unable to discharge energy rapidly, which is a required attribute for this class of products.  Rapidly discharging a low-power, dense lithium-ion battery overheats the cell, leading to thermal runaway.  Our lithium-ion powered e-bikes initially tested well.  But apparently, a pack had to experience several of these over-stress charge/discharge cycles before cells failed and ignited.  Shortly after launching sales of our lithium-ion battery-equipped e-bikes, we started receiving reports of battery fires from the field.  Fortunately, only property damage, but no injuries, were reported.  We ended up replacing all the lithium-ion battery packs we sold with heavier, less energy-dense nickel metal hydride batteries to protect our customers.

Fortunately, the battery industry has since developed high-power-density lithium-ion cells, and lithium-ion battery packs are now ubiquitous in today’s electric bicycles.

I relate this history to make a point.  That point is that industry has been aware of the propensity of lithium-ion batteries to fail catastrophically if they are of poor quality, adapted to applications inappropriate for the battery’s configuration, improperly stored, charged, and/or maintained, damaged in service, etc.  The industry has been aware that special precautions must be undertaken at all points in the specification, design, manufacture, pack construction, certification, integration, distribution, and sale of lithium-ion battery-equipped products.  Appropriate training of all personnel in the production and distribution chain is important so that due care is exercised throughout the supply chain.  Retail dealers must be trained in safe handling, storage, and charging protocols to ensure the safety of their shops and staff.  Shops must be configured with the proper equipment necessary to handle and safely store these batteries.  Dealers must also be trained to advise their customers in the proper care and use of these energy-dense power supplies.  Finally, an efficient and effective recycling infrastructure must be in place to remove end-of-life, damaged and defective/recalled batteries from the marketplace in an expedient and safe manner.

I submit that these actions should have been undertaken proactively, prior to the introduction of these products into the marketplace.

This clearly has not been the case.  Our industry was not prepared.  We are now in a very reactive mode, attempting to retroactively implement appropriate controls and protocols.

Hindsight is 20/20.  Property damage, injury, and loss of life have occurred.  But reaction is better than no action.  And considering the value and benefit that society enjoys and will continue to enjoy with the widespread proliferation of e-bikes, it’s vitally important that we address these lithium-ion battery safety issues as aggressively and expeditiously as possible.

Safety issues associated with lithium-ion batteries have been recognized by the U.S. Consumer Product Safety Commission (CPSC) as well as by local, state, and federal governmental agencies.  State and local legislation has been promulgated in New York State, New York City, the State of California, and other jurisdictions to mandate certification to Underwriter Laboratories (UL) and other relevant standards, and to regulate lithium-ion battery storage and usage by the public.  However, these efforts have only been marginally successful.

Efforts made at the federal level include bipartisan cooperation in the U.S. Congress to pass federal legislation ordering the CPSC to develop and promulgate mandatory standards (based on the UL 2949, 2271, and 2272 standards with minor modifications).  However, the executive branch has blocked these efforts for political reasons. 

There is unanimous agreement that mandatory safety standards are required to address these issues.  The proposed UL standards specify design, construction, and manufacturing requirements necessary to produce safe and reliable lithium-ion battery packs and their battery chargers, as well as requirements for compatible vehicular electrical systems that utilize the energy from these battery packs.  Testing and certification of these products by OSHA nationally recognized testing laboratories (NRTL) provides not only definitive proof that the products comply, but also provides regular supplier factory on-site follow-up inspections to ensure continuing conformance to design and manufacturing requirements.

These product certification protocols are currently in place, but they are voluntary.  Given that the federal government has failed its responsibility to protect the consuming public from unsafe products, it’s time for the e-bike industry to stand up and police itself.

Our industry trade group, the National Bicycle Dealers Association (NBDA), has taken up the challenge.  Under the leadership and guidance of the NBDA, efforts have been undertaken to encourage e-bike shops to only buy and sell UL-certified products, to educate staff and consumers with respect to proper storage, care and use of e-bikes and batteries, and to take advantage of the battery recycling program administered by the not-for-profit agency Call2Recycle.

NBDA has developed and promulgated relevant advisories and sponsored numerous seminars and webinars on e-bike and e-bike battery safety.  NBDA administers the E-bike Safety and Standards Committee, which meets quarterly and brings experts from all associated disciplines to the table to formulate and act upon initiatives to enhance safety.

NBDA has recently formed its Governmental Affairs Committee to undertake lobbying efforts to counter the administration’s recalcitrance to enact mandatory requirements to further consumer safety.

Finally, NBDA will soon launch consideration of mechanical standards for both conventional bicycles and e-bikes to supplement and, if necessary, supersede outdated mechanical requirements in place since 1976 under 16CFR1512.

The industry cannot let the current situation stand.  The failure and subsequent damage and potential injury caused by dangerous lithium-ion e-bike batteries threatens to impact the continuing proliferation of these important micromobility vehicles.  Not only is the health of our industry at stake, but also the numerous benefits afforded to society by these incredible machines.

Contact Mike Fritz: mike@humanpoweredsolutions.com.