In September 2023, the 2023 version of the ANSI/CAN/UL/ULC 2271 will replace the 2018 version of the standard. This standard applies to battery safety testing of light-duty electric vehicles. The new version of the standard has changes in the definition of structural requirements, test requirements, etc.
Definition Change-New BMS definition: Battery control circuit with active protection device to monitor and keep the battery in its designated working area; prevent battery overcharge, overcurrent, overtemperature, temperature loss and overdischarge.
-New electric motorcycle definition: An electric motor vehicle has a seat or saddle for the rider and is designed with no more than three wheels in contact with the ground, except for tractors. Electric motorcycles are used on public roads, including highways.
-New electric scooter definition: a device weighing less than 100 pounds (about 45kg), and
a) with handlebars, a floor or seat where the operator can stand or sit, and an electric motor;
B) can be driven by an electric motor and/or human power;
c) when driven by an electric motor, the maximum speed on a flat road does not exceed 20mph (approximately 32 km/h).
-Example of changing a light electric vehicle (LEV). Eliminate electric motorcycles and join unmanned aerial vehicles (UAVs).
-New Personal Electric Mobile Device Definition: A mobile device for a single rider, with a rechargeable electric drive system that balances and propels the rider, and can provide a handle for grasping while riding. This device may or may not be self-balancing.
-Added primary overcurrent protection primary safety protection active protection device (BMS) passive protection device (fuse) definition.
-New sodium ion cell definition: similar to the physical ion cell structure, except that sodium is used as a transport ion. The positive electrode is composed of a sodium compound, the negative electrode is composed of carbon or a carbon-like product, and the electrolyte is composed of an aqueous or non-aqueous electrolyte and a sodium compound salt dissolved in the electrolyte. (e. g. Prussian blue cells or transition metal layered oxide cells)
-Metal materials are corrosion
-resistant. The corrosion resistance requirements for metal housings made of the following materials are exempted:
a) copper, aluminum or stainless steel;
B) bronze or brass, any of which contains at least 80% copper
· Increase the corrosion resistance requirements of iron shell:
indoor iron shell should adopt pond porcelain, spray paint, galvanized or other equivalent methods to prevent corrosion. CSA C22.2 No.942/UL 50E 600h salt spray test shall also be met. Reference may also be made to CSAC 22.2No 94.2/UL50E for other methods of achieving corrosion protection.
-Insulation class and protective earthing
The conformity of protective earthing systems can be evaluated according to the new intelligent test item of this standard-earthing continuity.
-Security Analysis
· New Security Analysis Example. The system safety analysis shall at least prove that the following conditions are not dangerous, but are not limited to the following conditions:
a) overvoltage and undervoltage of the battery; B) battery overtemperature, low temperature
c) battery overcurrent under charging and discharging conditions.
· Revision of safety protection device (hardware) requirements
to a)UL991 failure mode and effect analysis (FMEA) requirements;
b) Protection against internal failures to ensure compliance with functional safety requirements in UL60730-1 or CSAE60730-1 (Clause H.27.1.2);
c) Protection against failures to ensure functional safety requirements in CSA C22.2 No 0.8 (Section 55) (Category B requirements) to determine compliance and to determine the micro-tests required to verify single fault tolerance.
-Revision of safety protection device software requirements:
a)UL 1998;
B) CSAC222No.08 Software Class B requirements;
c) Control requirements for software used in UL60730-1 (clause H.11.12) or CSAE60730-1 (software class B requirements).
-Added BMS for cell protection requirements: If the
relies on the battery management system (BMS) to maintain the cell within its specified operating range, the BMS shall maintain the cell within the specified battery voltage and current range to prevent overcharge and overdischarge. The BMS shall also keep the cells within the specified temperature range to prevent overheating and low temperature operation. When reviewing the safety circuit to determine the cell operating area limit to be maintained, the tolerance of the protection circuit/component should be considered. Components such as fuses, circuit breakers, or other equipment and components determined to be necessary for the intended operation of the battery system shall be provided in the end-use LEV and shall be identified in the installation instructions.
. -New protection circuit requirement: If the
exceeds the specified operating limit, the protection circuit shall limit or shut down the charging or discharging to prevent the operating limit from being exceeded. When a dangerous scenario occurs, the system shall continue to provide safety functions or enter a safe state (SS) or a risk handling state (RA). If the safety function is damaged, the system should remain in the safe state or risk processing state until the safety function is restored and the system is considered operational.
-New EMC requirement: Solid state circuits and software controls
as primary safety protection, if not tested as part of functional safety standard evaluation, shall be evaluated and tested according to UL 1973 electromagnetic immunity test to verify electromagnetic immunity.
Cell:
Add requirements for sodium ion cell. Sodium ion cells shall meet the requirements of UL/ ULC 2580 for sodium ion batteries (the same as the performance and marking requirements of secondary batteries in UL/ULC2580) and shall meet all performance tests of the cells.
. Add requirements for secondary use of cells. Batteries and battery systems using secondary use cells and batteries shall ensure that the components comply with the secondary use process of UL 1974.
Test changes
, overcharge
added During the test, the voltage requirements of the battery cell shall be measured.
When adding a test If the BMS reduces the charging current to a lower value near the end of the charging phase, it shall continue to charge the sample with the reduced charging current until the end of the requirement is canceled. If the protection device in the circuit is activated, repeat the test at 90% of the trip point of the protection device or a certain percentage of the trip point that allows charging for at least 10 minutes. At the end of the new test, the maximum charging voltage measured by the cell shall not exceed the requirements of its normal working area.
· High-rate charging
adds a high-rate charging test (the test requirements are the same as UL1973): the test results take into account the delay of BMS, and can allow the overcharge current to exceed the maximum charging current detected by MCM for a short time (within a few seconds), as long as it is within the delay time of BMS detection.
The short circuit
is canceled. If the protection device in the circuit is activated, repeat the test for at least 10 minutes at 90% of the trip point of the protection device or a certain percentage of the trip point where charging is allowed. Overload
is required. Add overload test (test requirements are the same as UL 1973).
During the test, the voltage requirements of the
shall be measured when adding over-discharge cells.
At the end of the test, the minimum discharge voltage measured by the battery core shall not exceed the requirements of its normal working area.
Temperature test (temperature rise)
if the maximum charging parameter changes with temperature, the corresponding relationship between the charging parameter and temperature shall be clearly defined in the charging instructions, and the charging requirements shall be carried out for the tested equipment according to the most stringent charging parameter. Changed pre-test preconditioning requirements. At least 2 complete charge and discharge cycles need to be performed until successive charge and discharge cycles do not continue to raise the maximum temperature of the cell by more than 2°C. (The old version is for 5 charge and discharge cycles)
The requirement that thermal protection and overcurrent protection devices shall not be operated during the test is added.
The grounding continuity test is added to the
grounding continuity
(the test requirements are the same as UL 2580).
Single cell failure tolerance test (heat spread) of
is newly added. For secondary batteries with rated energy greater than 1kWh, single cell failure tolerance test shall be carried out according to UL 2580..
