More Technology Safety On Batteries


Well-Known Member
I was recently in a sub-forum and the manufacture was saying they have obtained certification on their batteries that is UL-2271.

So what exactly is the UL2271 certification?
UL2271 is a standard for batteries used in Light Electric Vehicles (LEV) that was released in December 2016 by Underwriters Laboratories a global safety science organization. The standard covers the safety requirements for the design, manufacture, and testing of lithium-ion batteries used in LEVs.
It has become a necessity for all lithium batteries used in light electric vehicles (LEV) being traded in the US to be certified by Underwriters Laboratories (UL) in order to ensure the safety of both the user and the product. The UL2271 standard was created in order to ensure that all batteries used in EVs meet a certain level of safety.
The UL2271 standard is based on the existing UL 1642 standard for lithium-ion batteries, with additional requirements specific to batteries used in EVs. The standard is intended to address the unique hazards associated with lithium-ion batteries, such as thermal runaway, overcharging, and over-discharging.
The UL2271 standard is voluntary, but many light electric vehicle manufacturers are choosing to certify their batteries to the standard in order to give consumers assurance of the safety of their products.

What is involved.
The testing involved with UL2271 certification covers several aspects:

1. Electrical Testing
Overcharge Protection: Tests to ensure the battery can handle overcharging without failure.
Short Circuit Protection: Assessments to verify the battery's ability to withstand short circuits without causing harm.
Over discharge Protection: Evaluations to confirm that the battery can handle being overly discharged without damage.
Current and Voltage Limits: Ensuring the battery operates within specified current and voltage ranges.

2. Mechanical Testing
Vibration: Testing the battery's ability to withstand vibrations that simulate real-world usage in vehicles.
Shock: Assessing the battery's resilience to sudden impacts or shocks.
Drop Test: Checking the battery's durability by dropping it from a specific height.

3. Environmental Testing
Temperature Cycling: Evaluating the battery's performance across a range of temperatures, ensuring it can handle both high and low extremes.
Humidity Exposure: Testing the battery's resistance to high humidity environments.
Thermal Shock: Assessing the battery's ability to withstand rapid temperature changes.

4. Chemical Testing
Electrolyte Leakage: Ensuring there is no leakage of electrolytes under normal and abusive conditions.
Corrosion Resistance: Checking the battery's resistance to corrosion.

5. Abuse Testing
Crush Test: Simulating a scenario where the battery is crushed to ensure it does not fail dangerously.
Penetration Test: Assessing the battery's response to being penetrated by a sharp object.
Forced Discharge: Testing the battery's reaction to forced discharge conditions, ensuring it does not lead to thermal runaway or other failures.

6. Safety Features Testing
Battery Management System (BMS): Verifying the functionality of the BMS, which is responsible for monitoring and managing the battery's operations, including overcharge, overdischarge, short circuit, and thermal management.

7. Performance Testing
Capacity and Energy Density: Measuring the battery's capacity and energy density to ensure it meets the required specifications.
Cycle Life: Testing the battery's ability to maintain performance over a specified number of charge-discharge cycles.
Efficiency: Assessing the battery's charge and discharge efficiency.

These tests are comprehensive to ensure that batteries used in light electric vehicles are safe, reliable, and perform as expected under a wide range of conditions. The certification process involves rigorous testing and evaluation by UL (Underwriters Laboratories) to ensure compliance with the UL2271 standard.

Unlike other ULC standards on products, this UL standard is voluntary, it helps consumers to understand they are getting the safest batteries currently on the market.
@Ebiker33 as a safety engineer of UL Solutions for close to 19 years and having been involved with battery safety for 10+years, for the most part I agree with the above "what is involved" for UL 2271. However, keep in mind UL 2271 does a lot more than test battery packs, it assesses the components, construction, design, markings, materials, and user instructions of the battery pack. It also requires functional safety to be conducted on the BMS evaluating software to standards like UL 1998 and the hardware reliability of the control boards to standards like UL 991.

Please note a certified battery pack to UL 2271 does not mean the e-bike, e-scooter, or other end product that utilizes that battery pack has been evaluated and tested for electric shock, explosion, or fire risk. The end product standard for e-bikes is UL 2849 and for e-scooters is UL 2272. Look for certified products when purchasing e-bike or e-scooter.

This is no different then every laptop on the market having a safety certification to UL 62368-1 (standard for IT, Audio Video, and Communication equipment) and that the battery packs within them being certified to either UL 62133-2 (portable batteries) or UL 2054 (household/commercial batteries). Also power tools, personal groomers, and other end products all have certified battery pack along with the end product being certified. There are various conditions and foreseeable use and misuse conditions that can not be evaluated and tested until a battery is in it's final application.

It's important for the e-bike community continue to advocate for safety certified products sold to consumers to improve public safety and continue to keep the e-bike industry flourishing.