Why a small circuit board is used in mobile phone battery?

Why a small circuit board is used in mobile phone battery?

The lithium-ion battery used everywhere like mobile phones, laptops, and even electric cars etc. You have probably noticed that a small board is used in mobile phone batteries. So there is a question arise why a small board is used in mobile phone battery.

Let’s know why a small circuit board is used in mobile phone battery,

                        Lithium-ion batteries are now the most efficient type of batteries they are compact has high energy intensity lack of parasitic memory effect but have one significant drawback the fact is that they are operating and the process of charging should be carefully monitored.


                        If the battery discharges below a certain limit there is a high probability that it will fail. The same is in the case of overcharging. The voltage of a fully charged lithium-ion battery is 4.2 volts. In this condition, recharging can cause blistering and even the explosion of the battery. The same will happen in the case of overload and short circuits.

The board which you noticed in the mobile phone batteries, that’s a protection board. The board protects from a deep discharge from overcharging and from short circuits or over current. On the board, you can clearly see a couple of chips resistors, and capacitors. The circuit is made by Field Effect Transistors.
The board also protects from overheating and provides uniform charge by balancing the voltage. So the common functions of this protection board are,

1. Overcurrent/Short Circuit Protection
2. Overcharge Protection
3. Over-discharge Protection
4. Temperature Monitoring and Protection
5. Voltage and Current Sensing

The protection board acts as a safeguard for the battery from excessive current flow due to a short circuit. It detects abnormal currents and quickly interrupts the circuit to prevent damage to the battery or the connected device. The protection board prevents the battery from being overcharged by monitoring the battery voltage during charging. It disconnects the charging current when the battery reaches its maximum safe voltage, preventing overcharging and potential damage to the battery. Similarly, the protection board prevents the battery from being discharged below a safe voltage level. It monitors the battery voltage during discharge and disconnects the load when the voltage drops to a predefined threshold. 

Read also:

• Why mobile battery has more than two terminals?
• How a Mobile Charger works?

Thank you for visiting the website. keep visiting for more updates.