Introduction of several wiring methods for lithium battery protection board

Some lithium-ion batteries are the third temperature protection line, and some are battery information check lines (such as changing the non-original battery to alert).

Lithium-ion batteries are battery plus protection panels. The 3- wire will only appear on the protection panel, and the battery will always have only 2 wires.

There are two kinds of lithium ion batteries, and the obvious 3.7V is non-phosphorous aluminum and aluminum, which can be directly changed.

The replacement is very simple (note the positive and negative):

1: Remove the original battery pack, and then solder the iron to separate the protection board from the battery.

2: Also remove the protective plate of your new battery and connect the battery to the old protection board.

Introduction to lithium battery protection board

Lithium battery protection board is the charge and discharge protection for the series lithium battery pack; when fully charged, it can ensure that the voltage difference between each unit battery is less than the set value (generally ±20mV), and realize the equalization of each unit of the battery pack. , effectively improving the charging effect in the series charging mode; simultaneously detecting the overvoltage, under voltage, over current, short circuit, and over temperature conditions of each single cell in the battery pack, protecting and extending the battery life; under voltage protection enables each A single battery prevents damage to the battery due to over discharge during discharge.

The finished lithium battery consists mainly of two major parts, a lithium battery core and a protective plate. The lithium battery core is mainly composed of a positive electrode plate, a separator, a negative electrode plate and an electrolyte; the positive electrode plate, the separator and the negative electrode plate are wound or laminated, packaged, and poured into the electrolyte. After the package is made into a battery core, the role of the lithium battery protection board is not known to many people. The lithium battery protection board, as the name implies, is used to protect the lithium battery. The role of the lithium battery protection board is to protect the battery but not charge it. Stream, there is output short circuit protection.

Lithium battery protection board connection

There are two ways to design the lithium battery protection board, which are the positive and negative plates. The principle and purpose are the same, but the device does not support the software to modify the settings of the positive and negative protection boards, so it can only be physically correct. Connect to determine the protection mode, and the software used is different. The following describes the connection methods and operation methods of the two protection boards.

Introduction to several wiring methods for lithium battery protection board

The connection method of the battery protection board is generally the same as the negative protection board, the negative pole board, and the positive board. The other methods are not described one by one. The details are as follows:

Schematic diagram of wiring

1. Protection board connection battery wiring sequence: ☆ Special attention: The wiring of different manufacturers is not common. Please make sure to use the matching cable: 1 Ensure that the cable is not inserted into the protection board before connecting the cable; 2 Protect the board B-line (blue The thick color line is soldered to the total negative pole of the battery; the 3rd line is connected from the thin black line to B-, the second line (thin red line) is connected to the positive pole of the first string of batteries, and the positive pole of each string of batteries is connected in turn, until the last one String B+; After the 4th cable is connected, do not insert the plug directly into the protection board, measure the voltage between each two adjacent metal terminals on the back of the plug. If the voltage of the ternary polymer battery should be between 2.8~4.2V, the iron-lithium battery It should be between 2.5~3.65V, lithium titanate battery should be between 1.6~2.8V; after the 5-wire wiring sequence and voltage are confirmed, insert the protection board socket again.

2. After wiring is completed: measure whether the battery B+, B- voltage and P+, P- voltage are equal, it means that the protection plate works normally and can be used normally. If not, please recheck according to the above wiring sequence. PS: the method of connecting this line with the port and the tap port is the same, the difference is that they discharge connection (load, motor) and charging method is not the same. The negative electrodes of charge and discharge in the same port are connected on the p-line. The charging line is connected to the c-line and the discharge line is connected to the p-line.

Demonstration of the actual case diagram (take 7-string battery as an example)

1 Make sure that the cable is not inserted into the protection board before connecting the cable;

2 Solder the protection board B-line (blue thick line) to the battery negative

3 The cable is connected from the thin black line to B-, the second line (thin red line) is connected to the positive pole of the first string of batteries, and the positive pole of each string of batteries is connected in turn, until the last string B+;

4 

1. Press the B-line terminal and the multimeter red test lead B1 line terminal with the black pen of the multimeter to obtain the first series battery voltage is 3.584V.

2. By pressing the B1 line terminal with the multimeter black test pen and the red table pen pressure letter B2 line terminal of the multimeter, the second series battery voltage is 3.584V.

3. Measuring by this method, it is concluded that:

The first string battery voltage: 3.584V

The second string battery voltage: 3.584V

The third string battery voltage: 3.585V

The fourth string battery voltage: 3.585V

The fifth string battery voltage: 3.583V

The sixth string battery voltage: 3.583V

The seventh string battery voltage: 3.584V

The 7-string voltage is 3.58V, the wiring is correct, and the battery voltage difference is less than 0.002V, and the battery consistency is good.

5 After the wiring sequence and voltage confirmation are correct, insert the protection board socket again;

6 By connecting the B-line, measure the voltage of B- and the total positive electrode of the battery and the voltage of P- and the total positive electrode of the battery.

The voltage is the same, indicating that the protection board is normal (the protection board is equivalent to the switch, the switch is already open, and the current can pass safely)

Example test:

B-to the battery total positive voltage is 25.11V

P-to the battery total positive voltage is 25.11V

The two voltages are consistent to indicate that the protection board is normal. If P- discharges through a large current, there will be a slight pressure drop, and the protection plate will heat up (about 50 degrees), which is a normal phenomenon.

Same port protection board wiring application example

1 After the battery protection board is connected, we have to connect the charging and discharging line behind.

2 The red line in the charging line is connected to the red line in the discharge line (with load) above the total positive electrode of the battery.

3 The black wire in the charging wire is connected to the black wire in the discharge line (with load) on the P-line of the lithium battery protection board.

Split port protection board wiring application example

The red line in the charging line is connected to the red line in the discharge line (with load) above the total positive electrode of the battery.

The black wire in the charging wire is connected to the black wire in the C-line discharge wire (with load) on the lithium battery protection board.

Precautions

The connection cable must be correct. If the wrong line is connected, the protection board will be burned out. Therefore, the voltage of each string is confirmed by the voltage to ensure that the line is not connected incorrectly.

If it is an old battery, the voltage difference between each string of the battery is greater than 0.1V. The battery string with large difference is likely to have virtual power, and the capacity and resistance change, which will form a short board effect of the barrel, resulting in overcharge and overcharge protection. It can be simply understand that the battery life is short, and the application of the electric vehicle and other application scenarios using time is short.

The protection board protects each string of batteries, and any string of overcharge or over discharge will cause protection.

The page contains the contents of the machine translation.