The lithium battery protection board also has a equilibrium protection function, which has two modes of energy consumption and energy conversion. Energy dissipation equilibrium refers to consume excess power of the battery pack or the single cell with high voltage through the use of internal resistance. Energy consumption balancing is divided into balancing during charging, fixed-point voltage balancing, and static automatic balancing.

In this passage if you are going to learn more about PCB protected battery, please check and read the content for more professional information.

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What Are the Working Principles of PCB Protected Battery?

When the protection board is normal, Vdd is high level, Vss, VM is low level, DO and CO are high level. When any parameter of Vdd, Vss, VM is changed, the level of DO or CO will be change has occurred.

Overcharge detection voltage

In the normal state, Vdd gradually rises to the voltage between VDD and VSS when the CO terminal changes from a high level to a low level.

Overcharge release voltage

In the state of charge, Vdd gradually decreases to the voltage between VDD and VSS when the CO terminal changes from low level to high level.

Over discharge detection voltage

In the normal state, Vdd gradually decreases to the voltage between VDD and VSS when the DO terminal changes from a high level to a low level.

Over discharge release voltage

In the overdischarge state, Vdd gradually rises to the voltage between VDD and VSS when the DO terminal changes from low level to high level.

Over current 1 detection voltage

In the normal state, the VM gradually rises to the voltage between VM and VSS when DO changes from high level to low level.

Over current 2 detection voltage

In the normal state, the VM rises from OV at a speed of 1 ms or more and 4 ms or less to the voltage between VM and VSS when the DO terminal changes from a high level to a low level.

Load short-circuit detection voltage

In the normal state, the VM rises at a speed of 1 μS or more and 50 μS or less from OV to the voltage between VM and VSS when the DO terminal changes from a high level to a low level.

What is the working process of PCB protected battery?

When the cell voltage is between 2.5V and 4.3V, the first pin and the third pin of DW01 both output high level (equal to the supply voltage), and the second pin voltage is 0V. At this time, the voltage of pin 1 and pin 3 of DW01 will be applied to pins 5 and 4 of 8205A respectively. The two electronic switches in 8205A are in the conducting state because their G poles are connected to the voltage from DW01, that is Both electronic switches are in the open state. At this time, the negative pole of the battery is directly connected to the P- terminal of the protection board, and the protection board has a voltage output.

PCM or PCB ( protection circuit module or board ) is the "heart" of Lithium battery pack.  It will protect Lithium battery pack from overcharging, over-discharging and over-drain, therefore it is the must to have to avoid Lithium battery pack from explosion, fire and damage.

For low voltage lithium battery packs (<20 cells), you shall choose PCM with equilibrium function to keep each cell in balance and good service life. For high voltage Lithium battery pack (>20 cells), you shall consider advanced BMS ( battery manage system) to monitor each cell's performance to ensure battery's safer operation.

A battery management system (BMS) is any electronic system that manages a rechargeable battery (cell or battery pack), such as by monitoring its state, calculating secondary data, reporting that data, protecting the battery, controlling its environment, and / or balancing it. A BMS may monitor the state of the battery as represented by various items, such as:

·  Voltage: total voltage, or voltages of individual cells

·  Temperature: average temperature, or temperatures of individual cells

·  State of charge (SOC) or depth of discharge (DOD): to indicate the charge level of the battery

·  State of health (SOH), a variously-defined measurement of the overall condition of the battery

·  Current: current in or out of the battery

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