20Ah 3.2V Rechargeable LiFePO4 Battery Pack High Rate UL UN38.3 IEC62619 Approval

2.1

Nominal Capacity

20Ah

25±5℃,1C discharge

2.6

Max charge Voltage

3.65V

At CC mode

2.7

End-of-charge Current

0.05C

At CV mode

2.8

Cut-off discharge Voltage

2.00V

2.9

Standard Charge Method

1C CC/CV

2.10

Max Continuous Discharge current

10C

Discharge Time: 6minutes

2.11

Max pulse Discharge Current

14C

Discharge Time: 10 seconds

2.12

Cycle Life

2500cycles

At room temperature 25℃;

1C Continuous Discharge and 1C continouse charge current; ≥80% SOC (100% DOD)

25±5℃

2.13

Calendar Life

5 years

2.14

Charging Temperature

2.15

Discharging Temperature

-20～55℃

2.16

Storage Temperature

2.17

Apprearance

4.1 High Temperature

Discharge Performance

The cell was charged in accordance with 3.2, and stored in an ambient temperature of 55℃±3℃ for 5h, then discharged to cut-off voltage with a constant current of 1C. After that, fetch out the cell and place it in the ambient temperature of 25℃±5℃ for 4h then check its appearance.

Capacity retention at 55℃

:≥95%

4.2 Low Temperature Discharge Performance

The cell was charged in accordance with 3.2, and stored in an ambient temperature of -20℃±3℃ for 24 hours, then

discharged to cut-off voltage 2.0V at a constant current of 1C. After that, fetch out the cell and place it in the ambient

temperature of 25℃±5℃ for 4hours, then check its

appearance.

Capacity retention at -20℃

:≥80%

4.3 Rate Charge Performance

in Normal Temperature

Under the ambient temperature of 25℃±5℃

1. Discharged the cell with 1C constant current until the cut off voltage to 2.0V, stay for 1h.
2. Charged the cells with 5C constant current until the voltage to 3.65V, stay for 1h.
3. Discharged the cells with constant current until the cut off voltage 2.0V.

5C charge capacity≥80%

4.4 Rate Discharge Performance in Normal Temperature

The cell was charged in accordance with 3.2, then discharge to cut-off voltage 2.0V with 10C current in an ambient

temperature of 25℃±5℃.

10C discharge capacity≥95%

4.5 Cycle Life

(25℃±5℃)

The cell was fully charged to 3.65V with 1C (cc/cv), after that stayed for 30min; Subsequently, the cell was discharged to cut-off voltage 2.0V with constant current 1C, and stayed 30 minites; prior to next charge-discharge cycle. Record all the

cycles until the retention capacity＜80%.

≥2500cycles

No

.

Item

Test Method

Criteria

6.1

Temperature shock test

A cell is charged in accordance with 3.2, and then repeat the following procedures for 5 cycles, then check the cell's appearance.

No leakage, no fire, no explosion, no vent

6.2

Low-pressure Test

The cell is charged in accordance with 3.2, then stored for 6h at a vacuum of -90KPa, after that put the cell in room temperature for 6h, then check the cell's appearance.

No leakage, no fire, no explosion, no vent

6.3

Vibration Test

The cell is charged in accordance with 3.2, and then installed onto the vibration machine. Equipment parameters of frequency and amplitude are set as bellow (the frequency is to be varied at the rate of 1oct/min between 10 and 55 Hz, and repeat vibration for 30 min. The cell is tested in three mutually perpendicular directions, i.e. X,Y,Z):

1. frequency:10Hz~30Hz, amplitude: 0.38mm;
2. frequency:30Hz~55Hz amplitude: 0.19mm

No scratch, no fire, no explosion, no vent;

The voltage is

not less than 3.2V.

6.4

Shock Test

The cell is tested in accordance with 3.2, and then secured to the testing machine by means of rigid mount which supports all mounting surfaces of the cell. Each cell shall be subjected to a total of three shocks of equal magnitude. The shocks are to be applied in each of three mutually perpendicular directions. The acceleration and impulse time are as follows: acceleration of impulse peak value: 100m/s2, shock frequency:40~80 times/min, impulse lasting time:16 min, shock times:1000±10

No scratch, no leakage, no fire, no explosion, no vent;

the voltage is not less than 3.2V.

7.1

Short- circuit Test

No fire, no explosion

7.2

Overcharge Test

The cell was tested in accordance with 3.2, then 1C constant current charged till the voltage reaches 1.5 times of the specified end-off charge voltage, or the charge time reaches 1h, then stop charge, and observe for 1h.

No fire,no explosion

7.3

Over discharge test

The cell was tested in accordance with 3.2, then 1C discharge for 90min, then observe for 1h.

No fire, no explosion, no leakage

7.4

Crush Test

No fire, no explosion

7.5

Impact Test

No fire, no explosion

7.6

Stick Test

1. The cell was tested in accordance with 3.2
2. use φ5mm～φ8mm high temperature

resistance steel needle, with speed of

25±5mm/s, to go through the cell from vertical

direction of pole plate, the penetrate position

should be close to the geometric center of plate

surface, the steel needle remains in the cell;

No fire, no explosion

7.7

Heating Test(130℃)

The cell was tested in accordance with 3.2, and then heated in a circulating air oven. The temperature of the oven is raised at a rate of

5℃ per minute to 130℃±3℃ and remain for 30

min.

No fire, no explosion