INR18650-2850 3.7V Li-ion battery cell,Low internal resistance, high current discharge, high cycle

Safety performance test

1.Crush Test

A cell is to be crushed between two flat surfaces. The force for the crushing is to be applied by a hydraulic ram or similar force mechanism. The flat surfaces are to be brought in contact with the cells and the crushing is to be continued until an applied force of 13 ±1 KN is reached. Once the maximum force has been obtained is to be released. 

No explosion，no fire 

2.Heating Test

A cell is to be heated in a gravity convection or circulating air oven. The temperature of the oven is to be raised at a rate of 5℃ per minute to a temperature of 130±2℃ and remain for 30 minutes and observed for 1 hour. 

No explosion，no fire 

3.Over-charge Test 

The cell is discharged according to the standard discharge method. Apply a 1C Constant current 12V constant voltage charge for 1.5h.

No explosion，no fire，no leakage

4.Short-circuit Test 

Short-circuit the standard charged cell by connecting positive and negative terminal 10min by less than 5mΩ wire.

No explosion，no fire 

5.Low Pressure

Each fully charged cell is placed in a vacuum chamber with the ambient temperature (20±5℃ ). Once the chamber has been sealed, ts internal pressure is gradually reduced to a pressure equal to or less than 11.6KPa held at that value for 6 hours. And it need take 1 hour to observe. 

No explosion，no fire，no leakage

6.Seawater Immersion

Each fully charged cell is immersed in 3.5% NaCl solution(weight percent, this solution concentration is same to seawater) for 2 hours.

No explosion，no fire 

7.Temperature Cycling 

The fully charged cell shall be stored at the test temperature of 75± 2℃ for at least 6 hours, and then at the test temperature of -40± 2℃ for at least 6 hours. The maximum time interval between the two extreme test temperatures is 30 minutes. This procedure must be repeated 10 times, followed by the storage of all test cells and battery packs at ambient temperature (20±5℃) for 24 hours 

No explosion，no fire，no leakage

8.Drop Test

At normal temperature, the fully charged fresh cell will fall freely onto the cement road surface at a drop height of 1.5m. The two end surfaces of the cell dropped once each, and the cylinder dropped 4 times. A total of 6 drop tests were carried out, and the appearance was observed after the experiment was placed for 24h. 

No explosion，no fire 

9.Over-discharge Test A cell is charged in accordance with （This "Standard Charge" means charging the cell with charge current of 0.5C and constant voltage 4.2V at 25°C, 0.05Ccut-off. ）, then discharged by 1C(2850mA) current for 90 min and observed for 1 hour.

No explosion，no fire，no leakage

10.Vibration characteristics

After standard fully charge, cell shall be attached to a vibration table directly and subjected to vibration that consists of 10 Hz to 55 Hz to 10 Hz at the speed of 1Hz/min in 180-200mins. The total excursion of the vibration is 0.8mm (0.060 inches). The cell shall be vibrated in each direction along axis of the cylinder and the vertical directions of axis of the cylinder. 

No explosion，no fire，no leakage