GB 42296-2022Safety technical requirements of charger for electric bicycles (English PDF)

5.1 Machinery safety and structure

5.1.1 Enclosure shock After testing according to the method specified in 6.1.1, the charger shall comply with the provisions of

21.1 in GB 4706.1-2005.

5.1.2 Drop After testing according to the method specified in 6.1.2, the charger shall comply with the provisions of 8.1, 15.1.1, 16.3, Chapter 29 of GB 4706.1-2005.

5.1.3 Vibration After testing according to the method specified in 6.1.3, the charger shall meet the following requirements:

a) All relevant parts are not deformed or fallen off;

b) Comply with the provisions of 5.2.2;

c) Can work normally.

5.1.4 Structure

5.1.4.1 The structure of the charger shall meet the following requirements:

a) Eliminate rough or sharp edges, that pose a hazard to the user during normal use or user maintenance;

b) Power the output circuit, through an isolation device (transformer, etc.);

c) Wood, cotton, silk, plain paper and similar fibrous or hygroscopic materials shall not be used as insulating materials, unless otherwise impregnated.

5.1.4.2 The protective impedance shall consist of at least two separate components, the impedance of which shall not change significantly, during the lifetime of the appliance. If any of these components is short-circuited or open-circuited, the value specified in

8.1.4 of GB 4706.1-2005 shall not be exceeded.

Note: Resistors complying with

5.5.6 in GB 4943.1-2022 and Y-class capacitors complying with GB/T 6346.14-2015 are considered to be sufficiently stable impedance components.

5.1.4.3 Appliances connected to the power supply through a plug shall be constructed, so that when the pins of the plug are touched during normal use, there will be no risk of electric shock due to overcharged capacitors.

Note: Capacitors with a rated capacitance of no greater than 0.1 µF are not considered to cause an electric shock hazard.

5.1.5 Internal wiring The internal wiring of the charger shall meet the following requirements.

a) When bushings are used as additional insulation for internal wiring, hold it in place by a reliable means.

b) The wiring path is smooth and has no sharp edges.

c) The wiring is protected, so that it does not come into contact with burrs, cooling fins or similar objects, that may cause damage to the insulation. There is a metal hole through which insulated wires pass; it has a flat, smooth surface or an insulating sleeve. Test according to the method specified in 6.2.4. The structure and casing of the charger shall provide adequate protection against accidental contact with live parts.

5.2.5 Abnormal operation

5.2.5.1 Wrong connection Carry out the test according to the method specified in 6.2.5.1. The charger shall have no current output; there is no electric shock, fire or mechanical hazard. The charger shall work properly, when connected correctly.

5.2.5.2 Short circuit Carry out the test according to the method specified in 6.2.5.2. The charger shall be free of any faults, electric shock, fire, mechanical hazards.

5.2.5.3 Fan stalling The charger, which is equipped with a fan, is tested according to the method specified in 6.2.5.3; meanwhile it shall comply with the requirements of 5.2.2.

5.2.5.4 Component failure Conduct the test according to the method specified in 6.2.5.4. Any component in the charger circuit, that is short-circuited or open-circuited (except components that meet the requirements of basic insulation, supplementary insulation, reinforced insulation), shall not have the following phenomena:

a) Electric shock, fire, mechanical hazards;

b) Lithium-ion battery chargers produce an output voltage, that is 15% higher than the rated maximum output voltage; lead-acid battery chargers produce an output voltage, that is 20% higher than the rated maximum output voltage;

c) A current is generated that lasts longer than

1.0 s and the effective value of the output current is higher than 200% of the rated current. After the above test, the charger is cooled to room temperature and shall comply with the requirements of 5.2.2.

5.2.6 Fuse

5.2.6.1 The input terminal of the charger shall be equipped with an independent fuse; its output terminal is on the circuit board AND an independent fuse shall be installed between it and the output wire.

5.2.6.2 The nominal current specification of the charger's output fuse shall not be greater than three times the nominal rated output current.

5.3.1 Low temperature After testing according to the method specified in 6.3.1, the charger shall work normally.

5.3.2 High temperature After testing according to the method specified in 6.3.2, the charger shall work normally.

5.3.3 Constant damp heat After testing according to the method specified in 6.3.3, the electrical strength shall comply with the requirements of 5.2.2.

5.3.4 Prevention of foreign matter intrusion Carry out the test according to the method specified in 6.3.4. The test probe shall not touch live parts.

5.3.5 Waterproof After testing according to the method specified in 6.3.5, the charger shall work normally AND the electrical strength shall meet the requirements of 5.2.2.

5.4 Heating and thermal runaway

5.4.1 Temperature rise Carry out the test according to the method specified in 6.4.1. The temperature rise of the charger surface, power cord, output cord shall meet the following requirements:

a) For metallic material, it is <= 30 K;

b) For non-metallic material, it is <= 50 K.

5.4.2 Over-temperature protection Carry out the test according to the method specified in 6.4.2. The charger shall cut off the output current within 15 minutes.

5.4.3 Overcharge cut-off Carry out the test according to the method specified in 6.4.3. When the charger charges the battery in the high efficient charging range, when the battery charge does not exceed

1.20 C (rated capacity), the charger shall automatically transfer to the next charging stage (state), OR cut off the output current.

5.4.4 Delayed cut-off Carry out the test according to the method specified in 6.4.4. When the charger charges the battery in the high voltage charging range, the duration shall not exceed 180 minutes. The charger shall automatically transfer to the next charging stage (state), OR cut off the output current. When the charger enters the trickle charging stage and the duration does not exceed 180 minutes, it shall automatically cut off the output current.

Note: Lithium-ion battery chargers and other chargers designed without trickle charging stage are not evaluated for the cut-off function in trickle charging stage.

5.5 Output interface safety

5.5.1 The output interface of the charger (nominal voltage 48 V and below) shall not be plugged into the input interface, that complies with the provisions of GB/T 2099.1 and GB/T 1002.

5.5.2 The plug and socket systems of chargers of different battery types cannot be plugged into each other. When the charger charges an unsuitable battery pack system, there shall be no output. Example: The output interfaces of two types of chargers, lead-acid battery charger and lithium- ion battery charger.

5.5.3 The two metal conductive parts of the positive and negative poles of the DC output terminal of the charger cannot be touched at the same time.

5.5.4 The effective value of the no-load output voltage of the charger shall not be higher than

5.5.5 The charger and the battery pack (system) being charged shall have a mutual recognition and collaboration agreement. Lithium-ion battery pack chargers or other battery pack chargers shall first recognize and cooperate with the battery pack (system) being charged, to confirm the technical parameters of the battery pack, before starting charging. Example 1: The technical parameters of lithium-ion battery pack include battery type, voltage, number of strings, battery capacity, etc. Example 2: The technical parameters of sodium-ion battery pack include battery type, voltage, number of strings, battery capacity, etc.

5.5.6 The positive and negative pole settings of the power terminal of the lead-acid battery charger's output interface shall comply with the requirements of Figure 1 and Figure 2. The positive and negative pole settings of the power supply terminal of the output interface of a lithium-ion battery charger or other battery charger shall comply with the requirements of Figure 3 and Figure 4.

5.6.2 Glow wire

5.6.2.1 For the insulating material parts inside the charger, that support the connections carrying current exceeding

0.2 A during normal operation, as well as the insulating materials within 3 mm of these connections, they are tested according to the method specified in

6.6.2.1 and shall pass the glow wire flammability test at 850 °C (GWEPT).

5.6.2.2 For the insulating material parts inside the charger, that support the current- carrying connections, as well as the insulating material parts within 3 mm from these connections, they are tested according to the method specified in 6.6.2.2. It shall pass the glow wire flammability test at 750 °C (GWEPT). However, if the above glow wire test is passed, BUT the flame generated during the test lasts for more than 2 s, THEN, the components within a cylindrical range, which has a 20 mm diameter and 50 mm height, above the connector shall be subjected to an additional needle flame test, in accordance with 6.6.4.1. However, components shielded by isolation baffles, that comply with the needle flame test, do not need to be tested. If meeting the following conditions, it can be considered to be resistant to the needle flame test:

a) There is no flame or burning in the specimen; the specified bottom layer or packaging tissue paper does not ignite;

b) After removing the needle flame, the flame or burning of the test sample is extinguished within 30 s, meanwhile the specified bottom layer or packaging tissue paper does not ignite.

5.6.3 Vertical combustion

5.6.3.1 The non-metallic materials in the charger shall be tested according to the method specified in 6.6.3. The specimen may be prepared from the finished product. If it is impossible to prepare a specimen from the finished product, it can be prepared separately. The thickness of the specimen shall not be larger than those of the relevant parts.

5.6.3.2 The charger enclosure material shall comply with the V-0 level requirements in GB/T 5169.16-2017.

5.6.3.3 The materials of components, which are installed in the opening of the charger enclosure, shall comply with the level V-0 requirements in GB/T 5169.16-2017. These components shall be limited to switches, indicator lights (except indicator light leads), connectors, appliance sockets.

5.6.3.4 The charger's fan material shall comply with level V-1 in GB/T 5169.16-2017.

5.6.3.5 Unless any one of the following items a), b),

c) is met, the materials of other internal components of the charger shall comply with level V-2 in GB/T 5169.16-2017:

a) The charger enclosure only has openings filled with connecting wires and openings for ventilation, which has a width not exceeding 1 mm and an unlimited length;

b) For small electrical components, if these components are installed on materials that comply with the vertical combustion level V-1 or better in GB/T 5169.16- 2017, such as integrated circuits, optocouplers, capacitor which has a volume not exceeding 1750 mm3;

c) Except for metals, glass, ceramics, the small mechanical parts whose non-metallic material mass does not exceed 4 g per part.

5.6.3.6 If the charger adopts glue filling process, the glue used shall comply with the V- 0 level in GB/T 5169.16-2017.

5.6.4 Needle flame

5.6.4.1 The base material of the printed circuit board, which is used in the charger, shall be tested according to the method specified in 6.6.4.1. Test is not performed on materials of category V-0 according to GB/T 5169.16-2017, when the base material specimen is not thicker than the printed circuit board. The following conditions can be considered to be resistant to the needle flame test:

a) There is no flame or burning in the specimen, meanwhile the specified bottom layer or packaging tissue paper does not ignite;

b) After removing the needle flame, the flame or burning of the test sample is extinguished within 15 seconds, meanwhile the specified bottom layer or packaging tissue paper does not ignite.

Note: If the charger uses glue filling technology and the glue filling covers the entire printed board, the base material of the printed board is not subject to undergo this test.

5.6.4.2 If the material of the charger enclosure and the components, which are installed in the opening of the charger enclosure, do not meet the specimen preparation conditions for the test of 5.6.3, THEN, the above materials shall be tested according to 6.6.4.2. The evaluation requirements are that after the first test flame is applied, the test sample shall not be completely burned out. After any test flame is applied, the burning duration of any sample shall not exceed 15 s, meanwhile the average burning time shall not exceed 10 s. Tissue paper shall not ignite; white pine boards are not carbonized either.

5.7 Emission

5.7.1 Terminal disturbance voltage Carry out the test according to the method specified in 6.7.2. The charger power current tester, to connect to any pole of the charger's input power supply; connect the other test rod to connect the accessible parts of the charger's metal foil, to measure the charger's leakage current.

6.2.2 Electrical strength Use a withstanding voltage tester, to perform an electrical strength test, between the charger's live parts and accessible parts (non-metallic parts covered with metal foil). The test voltage values are as follows:

a) Basic insulation: 1250 V;

b) Additional insulation: 1750 V;

c) Reinforced insulation: 3000 V. The voltage frequency of the test is

50 Hz; the time is 1 min; the trip current is set to 10 mA.

6.2.3.1 Electrical clearance Carry out the test, according to the method specified in

29.1 of GB 4706.1-2005.

Note: See Appendix B, for examples of charger's electrical clearance test.

6.2.3.2 Creepage distance Carry out the test, according to the method specified in

29.2 of GB 4706.1-2005.

Note: See Appendix B, for an example of the charger's creepage distance test.

6.2.3.3 Solid insulation Carry out the test, according to the method specified in

29.3 of GB 4706.1-2005.

6.2.4 Protection against electric shock Carry out the test, according to the method specified in Chapter 8 of GB 4706.1-2005.

6.2.5 Abnormal operation

6.2.5.1 Wrong connection Connect the input end of the charger to the power supply, to make it work normally. Connect an ammeter in series to the output end of the charger; then wrongly connect it to the positive and negative poles of the input end of a fully charged battery pack (the capacity of the battery pack is the maximum capacity, which is stated in the instruction manual). Hold for 10 minutes. Then disconnect it. Observe whether the ammeter reading is always less than 5 mA. After reconnecting correctly, check whether the charger work normally.

6.2.5.2 Short circuit Connect the input end of the charger to the power supply. Connect the output end to the electronic load, to make it work at full load. Take a plug, that matches the output end of the charger. Use a wire, which has a cross-sectional area greater than 1 mm2 (short- circuit resistance less than 50 mOmega), to short circuit the output ends of the charger, between the positive and negative poles of the plug; OR use an electronic load for short circuiting. Remove it after connecting for 15 s.

6.2.5.3 Fan stalling In the test, mechanical methods are used to artificially stall the fan for 30 minutes.