UL Test Standard / Specifications for Li-Ion
and packs
UL (Underwriters Laboratories) is an organization for testing and authenticating the products. UL is the symbol of safety for the consumers. UL is one of the most reliable qualified evaluating providers for the manufacturers on the global. UL 憇 test standard for Li-Ion Battery and pack is as the follows:
(1) Experiment of over-charging
Charge for the electric cores with the constant current and set up the upper limit for the fixed voltage. The interior electric core will arise the dendrite in the cathode. Penetrating the membrane is most important threaten for passing this experiment.
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Premise
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Environmental temperature
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Charging current
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Experimental process
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Time requirements
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Result requirements
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After charging according to the standards
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20℃ +/- 5℃
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Carry through the relative current and time .
Ic= 2.5C / 3 tc
Here, C is the standard capability of battery, ICis the testing current. tc is time ( hrs) to be test. => 48
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The testing time cannot be below 48 hours.
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No explosion and burning
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(2) Experiment of short circuit
Directly connect the conducting wire with the little resistance to the anode and cathode making the cell form the loop circuit with super heavy current and climb the interior temperature in the cell.
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Premise
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Environmental temperature
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Methods of short circuit
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Exterior resistance
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Time
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Result requirements
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After charging according to the standards.
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60℃ +/- 2℃
20℃ +/- 5℃
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Connect anode and cathode with conducting wires
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0.1 Ω
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Till the temperature close to the environmental temperature.
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No explosion, burning. The casing temperature can not be above 150℃
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(3)
Experiment of acupuncture
Penetrate the cell vertically with the iron needle. The interior circuit arises persistently.
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Premise
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Environmental temperature
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Steel needle
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Experimental process
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Time requirements
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Result requirements
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After charging according to the standards
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20℃+/- 5℃
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Bounce to the cells at the minimum acceleration of 75g and the maximum acceleration of 125
～
175g within 3ms on the face and side face of cell.
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No explosion and burning Ejection ≤ 5g
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(4)
Thermal impact
Put the electric core into the high temperature case. Ascend the temperature complying with the standard and regular speed. The persistent high temperature makes the interior membrane melt, which causes the interior short circuit with bulk areas.
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Premise
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Velocity of ascending temperature
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Upper limit temperature
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Time requirements
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Result requirements
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After charging according to the standards
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5℃ +/- 2℃
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150 ℃ +/-2℃
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Ten minutes
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No explosion and burning
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