Can a polymer lithium battery of the same model be connected in parallel with only one protective plate?

Often huge, are guarded by unremarkable things, like a car, brake and clutch combined are not much.

Today's mobile power, even all batteries are like this, especially batteries using polymer batteries, in this regard is even more urgent.

Nowadays, whether it is a mobile phone or a mobile power source, there are very few detachable batteries, but friends who have noticed the detachable mobile phone battery have known that the battery is divided into two parts, one is a battery core, and the other is a small one. The circuit board, through a small circuit board, we can charge and discharge.

And that small board is the protective board for polymer batteries.

After so many years of development, the current protection board has many models, and the performance of the version of the shield plate produced by different manufacturers is different, but the basic functions are still the same.

1) Overcharge protection function:

Overcharge protection means that it is prohibited to continue charging by the charger when the rated charging voltage is reached or exceeded. That is, the MOS tube that controls the overcharge is brought into an off state, and charging is stopped.

2) Over-discharge protection function:

The over-discharge protection function stops discharging the load when the battery voltage becomes low. The MOS tube that controls the over-discharge is put into the off state, and is prohibited from discharging. The product will therefore automatically shut down, creating an over-discharge protection that happens to be the opposite of the over-charge detection.

3) Over-current protection function:

The over-current protection function stops the discharge of the load when a large current is consumed. The purpose of this function is to protect the battery and the MOS tube to ensure the safety of the battery under working conditions. When the battery is discharged, the protection board has a maximum limit. The current is different for different products. When the discharge exceeds this current protection board, it will automatically turn off. After the over current detection, the battery will return to the normal state after being separated from the load and can be recharged or discharged.

4) Short circuit protection function:

When the battery is inadvertently short-circuited, the protection board will automatically turn off within a few milliseconds, and will not be energized. At this time, the positive and negative poles will touch one piece and it will be fine. A short-circuit protection will not cause a fire accident.

The safety and stability protection of the protection board for the charge and discharge of the battery is useless and even more uncuttable. Now whether it is a polymer or 18650battery, the circuit of the protection board is basically added to the circuit to ensure battery safety.

The most classic case must be Samsung note7. In order to increase the battery capacity, the size of the protection board is reduced. As a result, the circuit board is squeezed when the battery is released from heat, causing a short circuit between the positive and negative contacts, becoming a "bomb".

When the batteries are connected in parallel, the voltage is theoretically required to be exactly equal. If they are not equal, it will cause the high-voltage battery to charge to a low voltage, causing the battery to "guilty" or even be damaged. Conditionally, the voltage can be measured, and the difference is less than one hundredth of a volt.

Several polymer lithium batteries of the same type can be connected in parallel with only one protective plate, but the internal resistance voltage must also be the same. Otherwise it will affect the effect of use.

The page contains the contents of the machine translation.