SPP battery

1. Test method for short circuit protection

A. Connect the protection board to the cell and voltmeter as shown below and activate it. The no-load output voltage of P+P- should be equal to the cell voltage of B+B-.

B. Short-circuit P+P- with a wire for more than 1s, the voltmeter should read 0V, remove the wire and activate (automatic recovery), the voltage of P+P- should still be equal to the voltage of B+B-.

C. Short-circuit more than 10 times in the same way.

If there is no abnormality in the protection board every time it is short-circuiting (such as smoke, fire, buzzing, burnt smell, etc.), and the no-load output voltage after activation is equal to the battery cell voltage, the protection board short-circuits protection function could judge to qualify.

Remarks:

The battery cell voltage 3.6V-3.8V is half-charge short-circuit protection, 4.0V-4.2V is full charge short circuit protection.

Short circuit protection test connection diagram

Precautions:

The internal resistance of the short-circuit wire should be ≤20.0mΏ, the wire diameter ≥φ1.00mm

2. Test method for short circuit protection delay

A. Weld a 2512/10mΩ/±1% resistor at P-, and use the probe of the oscilloscope to collect the voltage across the resistor, as shown in Figure 1.

B. Short-circuit P+ P- at this time, and a waveform are obtained on the oscilloscope, as shown in Figure 2.

The short-circuit delay could obtain from the schematic diagram of the oscilloscope.

Figure 1:

Connection diagram for short circuit delay test

Figure 2:

Schematic diagram of oscilloscope short circuit delay

3.  Test method of overcurrent protection

The protection board is connecting to the electronic load (as shown in the figure). After activation, increase the current of the electronic load until protection.

The instantaneous current value before the load current jumps to 0 A is the overcurrent value. The process of adjusting current should complete within 3-5s.

During this process, the protection board should have no abnormal phenomena (such as smoke, fire, burnt smell, buzzing, etc.), and the no-load output voltage after the test should still be equal to B+ B-terminal voltage.

Precautions:

Ensure the voltage of the cell, and when the voltage is insufficient, connect the cell in parallel to help charge a constant current source, and adjust the voltage of the constant current source to be consistent with the cell to prevent the over-discharge protection state.

Overcurrent protection current test connection diagram

4. Test method of overcurrent protection delay

A. As shown in Figure 1, weld a 2512/10mΩ/±1% resistor at P-, use the probe of the oscilloscope to collect the voltage across the resistor, and connect an electronic load between P+ and the resistor.

B. The electronic load current is set to the upper limit of the overcurrent, the protection board enters the overcurrent protection state, and a waveform is obtained on the oscilloscope, as shown in Figure 2.

The delay could obtain from the schematic diagram of the oscilloscope.

Precautions:

Ensure the voltage of the cell, and when the voltage is insufficient, connect the cell in parallel to help charge a constant current source, and adjust the voltage of the constant current source to be consistent with the cell to prevent the over-discharge protection state.

Figure 1:

Connection diagram of overcurrent protection delay detection

Figure 2:

Schematic diagram of oscilloscope overcurrent delay

5.  Test method for discharge conduction

Connect the protection board according to the schematic diagram and activate it, set the load current to 1.00A, and then use a millivoltmeter to detect the voltages from P+ to B+ and P- to B-.

The sum of the two voltage values is the normal operation of the protection board Turn on the internal resistance.

Key points and precautions:

When testing, the millivoltmeter should connect to the corresponding pad of the protection board,  not on its connecting wire;

Schematic diagram of the internal resistance detection method during discharge

6.  Overcharge protection voltage detection method one

A. The protection board, electronic load, voltmeter, and programmable power supply are connected as shown in Figure

1:

The programmable power supply is used to simulate the cell voltage, and an electronic load is connected to the simulated cell.

The charger can be used (programmable power supply instead) to adjust the open-circuit voltage.

To n*4.5V (n means several cells are connected in series);

then start to gradually increase the analog cell voltage such as B+B4, until the charging current should be suddenly cut off to 0.00A, the reading of the voltmeter is the overcharge protection voltage value.

B. Use the same method as above to detect the overcharge protection voltage of other battery-saving cores.

Precautions:

The voltmeter should be tested to the B+,…, B- pads of the protection board.

Figure 1:

Connection diagram of B+B4 terminal overcharge protection voltage detection method

Figure 2:

Connection diagram of B4B3 terminal overcharge protection voltage detection method

7.  Test method of overcharge protection delay

As shown in Figure 1,

use the programmable power supply to simulate the cell voltage, set the probe of the oscilloscope to detect the charging terminal C+/C-, set one section of the programmable power supply to 4.5V, and the oscilloscope will have a waveform, as shown in Figure 2.

The specific delay could obtain from the oscilloscope graph. Use the same method as above to detect the overcharge voltage protection delay of other battery-saving cores.

Figure 1

Figure 2

8.  Test method for overcharge and sleep

Connect the protection board to the analog power supply, battery cell, and voltmeter as shown in the figure below and activate it, add the charger to C+ C- to charge the battery cell through the protection board, adjust the analog power supply to 4.3V, and the charger stops charging.

The voltage meter between VCC and B- within 1s shows 0V, and it could judge as overcharge dormancy.

9. Unplug the charger to sleep

The protection board and the battery cell are connected as shown in Figure 1 (the cell voltage should be 3.8±2);

under normal charging work (without overcharge protection) disconnect the charger as shown in Figure 2, and pay attention to the VCC of the protection board.

The voltmeter between B- and B- (the voltmeter should display 3.5V under normal operation) is about 30 seconds, and the voltmeter between VCC and B- displays 0V, and it can be judged as unplugging the charger and sleeping.

Figure 1

Figure 2

10.  Test method of over-discharge protection voltage

Adjust the open-circuit voltage of the programmable power supply to 3.8±0.2V and the short-circuit current to the maximum;

then connect it to the protective board with qualified overcharge protection voltage, programmable power supply, voltmeter, and electronic load as shown in Figure 1, and Activate, the constant current source ammeter should display a certain discharge current value;

then gradually reduce the voltage of the programmable power supply,

when the voltage reading of the multimeter drops to a certain value within the standard over-discharge protection voltage range (that is, the over-discharge at the B+ B1 terminal) Protection voltage),

the reading of the electronic load and the programmable power ammeter should suddenly turn off to 0A, that is, if there is no abnormal phenomenon in the detection of the over-discharge protection, (such as the reading of the voltmeter is unstable, the discharge current is only reduced.

When the shutdown is 0A, etc.), it could determine that the over-discharge protection voltage at the B+B1 terminal is qualified (that is, the over-discharge protection function is also qualified, record the voltage value).

Use the same method as above to detect the over-discharge protection voltage of other battery-saving cores (such as Figure 2);

if the test result is the same as the above and there is no abnormal phenomenon during the detection process,

it could determine that the over-discharge protection voltage of each section of the protection board is qualified.

Most important, If one or several of the above-mentioned abnormal phenomena occur during the detection or the over-discharge protection voltage is not within its standard value, or there is no discharge, I

t could judge that the over-discharge protection voltage of the protection board is unqualified or has no over-discharge protection function.

Figure 1:

Connection diagram of B+B1 terminal over-discharge protection voltage detection method

Figure 2:

Connection diagram of B1 and B2 terminal over-discharge protection voltage detection method 

Key points and precautions:

• The voltmeter should be as close as possible to the pads of the protection board B+, BM, and B-.

Each section has requirements for both function and data.

However, Only when the over-discharge protection function and data of all sections are normal, the over-discharge protection voltage of the protection board is qualified.

11.  Test method for delay of over-discharge protection

What's more. Use the programmable DC power supply to simulate the cell voltage, set the probe of the oscilloscope to detect the output terminals P+/P-,

as shown in Figure 1, set the programmable DC power supply B+/B4 terminal from 4V to 2V, then the oscilloscope.

The waveform appears, as shown in Figure 2, and the specific delay could obtain from the oscilloscope graph.

Use the same method as above to detect the over-discharge voltage protection delay of other battery-saving cores.

Figure 1

Figure 2

12.  Test method for over-discharge sleep

Connect the protection board to the analog power supply, battery cell, and voltmeter as shown in the figure below and activate them. Work with load at the output terminal and adjust the analog power supply voltage to 2.4V; the load stops discharging, and the voltmeter is between VCC and B- within 1mm If the display is 0V, it could judge as over-discharge sleep.

Figure 1

13.  Discharge sleep

The protection board is connecting to the battery (as shown in Figure 1) (the battery voltage should be 3.8±2); after loading, the voltmeter between the protection board VCC and B- under normal discharge work shows 3.5V; disconnect the load, Stop discharging, as shown in Figure 2. Pay attention to the voltage of the voltmeter. Within 5 minutes, the voltmeter between VCC and B- shows 0V, and it could judge as a discharging sleep.

Figure 1

Figure 2

14.  Self-consumption test method

Connect the protection board to the battery cell and the microammeter as shown in the figure, and activate it. After 60s, the reading of the microammeter after it stabilizes is the self-consumption current value of the protection board.