Blog in Bike Europe: E-bike battery fires and what the industry can do about it
By Rutger Oldenhuis
Did you see the horror crash of Formula 1 racer Zhoa at Silverstone this year? He survived, miraculously, due to a mandatory safety measure that was introduced in 2018 by car sports federation FIA: the halo. The halo is a titanium part that is placed over the driver’s cockpit. The design has a strong resemblance with the upper part of a flip-flop – just look at your Havaianas.
Perhaps that was the reason why nobody in car racing really liked the introduction of the halo until they saw it actually serve a purpose. Since its introduction, several drivers owe their lives to the halo, including Zhoa. It’s a great example of ‘safety by design’ and the FIA can take pride that they have pushed through with this innovation, despite all the opposition. And from flip flops, it’s only a small jump to e-bike battery safety.
Thermal runaway
Battery fires, mainly caused by so-called thermal runaway events, are an increasing concern in the bicycle industry. In e-bike paradise, the Netherlands, there are 6-8 battery fires reported every week, but the real number is probably even higher. Thermal runaway events can have many different causes and the risks can be serious. Some batteries are ticking time bombs and should not be on the market in the first place. So, what can the industry do to minimise the risks?
Risk assessment
One of the goals of product design is to minimise the product risks that have been identified with the risk assessment. Complying with a harmonised standard is essential, but only relevant for the risks and risk categories that are covered by that standard. A producer is expected to carry out a risk assessment and check whether the harmonised standard covers all risks of the product.
Safety hierarchy
Once the product risks have been identified, they can be minimised following the Safety Hierarchy principle, which is like a 3-stage rocket. Step 1 is about applying inherently safe design measures (‘safety by design’). Step 2 is about applying safeguarding and complementary protective measures (e.g., a chain guard). Step 3 is about reducing risk through information for use, e.g., a warning on the product and/or in the manual. Typically, all three steps are being used, but with a clear preference and hierarchy. Step 3 is a last resort measure.
Is a warning in a product manual sufficient?
Despite the instructions and warnings for use in product manuals, consumers tend to charge batteries in their bedroom, park their e-bike in the burning sun and continue using their battery after it has dropped or suffered from a crash. Whether that behaviour would lead to an exemption of producer liability is arguable. If warnings are notoriously and continuously ignored, then such careless behaviour becomes foreseeable, and the producer will have to act on that by taking extra precautionary measures.
Risk reducing measures
For example, why not sell an e-bike with a sun protective battery bag? Why not have more safety features built in the Battery Management System, like overheating, drop or crash detection, combined with a push message on a mobile app? Most modern mobile phones have a simple strip indicating if there is water damage. Why can’t a battery have a simple crash-sensitive device that indicates if a battery has suffered from external impact? Imagine how that could improve not only the safety of consumers but also reduce the risks for companies using e-bikes for B2B services, like postal, rental and bike-sharing services.
A call on the industry
The increasing number of battery fires are harming the e-bike image. Only safe e-bikes should be allowed on the market. Harmonised safety standards are developed together with industry experts. When developing standards for e-bikes, there is a great opportunity for the industry to raise the bar and improve the safety standard for batteries based on the current state of technical knowledge and possibilities. Take FIA as an example. If flip-flops can do it for Formula 1…
Blog in Bike Europe: E-bike battery fires and what the industry can do about it
By Rutger Oldenhuis LLM
Did you see the horror crash of Formula 1 racer Zhoa at Silverstone this year? He survived, miraculously, due to a mandatory safety measure that was introduced in 2018 by car sports federation FIA: the halo. The halo is a titanium part that is placed over the driver’s cockpit. The design has a strong resemblance with the upper part of a flip-flop – just look at your Havaianas.
Perhaps that was the reason why nobody in car racing really liked the introduction of the halo until they saw it actually serve a purpose. Since its introduction, several drivers owe their lives to the halo, including Zhoa. It’s a great example of ‘safety by design’ and the FIA can take pride that they have pushed through with this innovation, despite all the opposition. And from flip flops, it’s only a small jump to e-bike battery safety.
Thermal runaway
Battery fires, mainly caused by so-called thermal runaway events, are an increasing concern in the bicycle industry. In e-bike paradise, the Netherlands, there are 6-8 battery fires reported every week, but the real number is probably even higher. Thermal runaway events can have many different causes and the risks can be serious. Some batteries are ticking time bombs and should not be on the market in the first place. So, what can the industry do to minimise the risks?
Risk assessment
One of the goals of product design is to minimise the product risks that have been identified with the risk assessment. Complying with a harmonised standard is essential, but only relevant for the risks and risk categories that are covered by that standard. A producer is expected to carry out a risk assessment and check whether the harmonised standard covers all risks of the product.
Safety hierarchy
Once the product risks have been identified, they can be minimised following the Safety Hierarchy principle, which is like a 3-stage rocket. Step 1 is about applying inherently safe design measures (‘safety by design’). Step 2 is about applying safeguarding and complementary protective measures (e.g., a chain guard). Step 3 is about reducing risk through information for use, e.g., a warning on the product and/or in the manual. Typically, all three steps are being used, but with a clear preference and hierarchy. Step 3 is a last resort measure.
Is a warning in a product manual sufficient?
Despite the instructions and warnings for use in product manuals, consumers tend to charge batteries in their bedroom, park their e-bike in the burning sun and continue using their battery after it has dropped or suffered from a crash. Whether that behaviour would lead to an exemption of producer liability is arguable. If warnings are notoriously and continuously ignored, then such careless behaviour becomes foreseeable, and the producer will have to act on that by taking extra precautionary measures.
Risk reducing measures
For example, why not sell an e-bike with a sun protective battery bag? Why not have more safety features built in the Battery Management System, like overheating, drop or crash detection, combined with a push message on a mobile app? Most modern mobile phones have a simple strip indicating if there is water damage. Why can’t a battery have a simple crash-sensitive device that indicates if a battery has suffered from external impact? Imagine how that could improve not only the safety of consumers but also reduce the risks for companies using e-bikes for B2B services, like postal, rental and bike-sharing services.
A call on the industry
The increasing number of battery fires are harming the e-bike image. Only safe e-bikes should be allowed on the market. Harmonised safety standards are developed together with industry experts. When developing standards for e-bikes, there is a great opportunity for the industry to raise the bar and improve the safety standard for batteries based on the current state of technical knowledge and possibilities. Take FIA as an example. If flip-flops can do it for Formula 1…