How to activate protection board of lithium battery?

How to activate protection board of lithium battery?

What is the protection board of lithium battery?

Protection board of lithium battery 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, undervoltage, overcurrent, short circuit, and overtemperature conditions of each single cell in the battery pack, protecting and extending the battery life; undervoltage 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 wound or laminated, packaged, and poured into the electrolyte. After the package made into a battery core, the role of the protection board of lithium battery not known to many people. The protection board of lithium battery, as the name implies, used to protect the lithium battery. The role of the protection board of lithium battery is to protect the battery but not charge it. Stream, there is output short circuit protection.

Why do some protection board of lithium batteries need to activate? How to activate the protection board of lithium battery?

Protection board of lithium battery technical parameters

Equilibrium current: 80mA (when VCELL=4.20V)

Equilibrium control point: 4.18±0.03V overcharge threshold: 4.25±0.05V (4.30±0.05V optional)

Over-discharge threshold: 2.90±0.08V (2.40±0.05V optional)

Over discharge delay: 5mS

Over discharge release: disconnect the load, and each cell voltage is higher than the over-discharge threshold;

Overcurrent release: disconnect load release

Over temperature protection: There is an interface, and a recoverable temperature protection switch is required;

Working current: 15A (according to customer choice)

Static power consumption: "0.5mA

Short-circuit protection function: It can protect and disconnect the load and recover itself.

Main functions: overcharge protection function, over discharge protection function, short circuit protection function, over current protection function, over temperature protection function, balanced protection function.

Interface definition: The charging port and the discharging port of the board are independent of each other, the two are common to the positive pole, B- is the negative pole connecting the battery, C- is the negative pole of the charging port. P- is the negative pole of the discharging port; B-, P-, C - The pads are all via type, and the pad holes are all 3 mm in diameter; each charge detection interface of the battery is output in the form of a DC pin holder.

Parameter description: Configuration of maximum working current and overcurrent protection current value, unit: A (5/8, 8/15, 10/20, 12/25, 15/30, 20/40, 25/35, 30/50 , 35/60, 50/80, 80/100), special overcurrent values can be customized according to customer requirements.

Why do some protection board of lithium batteries need to activate? How to activate the protection board of lithium battery?

Detailed analysis of the principle of protection board of lithium battery

As we all know, lithium batteries are new energy batteries that used in various fields at present, but lithium batteries need protection from protection boards. Many people do not know that protection boards play a vital role in battery use. Let us understand the structure of the protection board and its protection principle.

The protection board has two core components: a protection IC that reliably protected by a precision comparator. The other is that the MOSFET string acts as a high-speed switch in the main discharge loop, performing a protection action, and the IC controls the MOS tube by monitoring the battery voltage difference. There are resistors, capacitors, and auxiliary FUSE, PTC, NTC, ID, and storage on the common protection board. B+ and B- on the protection board respectively connected to the positive and negative electrodes of the battery. P+ and P- are the positive and negative electrodes of the protection board output, respectively. The figure is a schematic diagram of a protection board:

Why do some protection board of lithium batteries need to activated? How to activate the protection board of lithium battery?

The protection board overcharges, over discharges, shorts, and overcurrent's, and protects the battery.

Lithium battery requires constant current and constant voltage during charging. In the initial stage of charging, it charged with constant current. With the charging process, the voltage rises to a certain value and converted to constant voltage charging until the current becomes smaller and smaller. When the battery charged, if the charging circuit loses control, the voltage will exceed a certain value and the constant current charging will continue, and the battery voltage will continue to rise, which will cause battery damage or safety problems. When there is a protection board in the battery, the overcharge protection function of the protection board will activated, the MOS tube will cut off, the battery pack prohibited from being charged, and the safety of the battery protected.

As with all other protections, the protection board constantly monitors the various conditions of the battery and takes protective measures.

Why do some protection board of lithium batteries need to be activated?

Now not all protection board of lithium batteries need to activated, but some protection ICs need to activated, and this is the old IC solution. The old IC solution needs to do this in order to make the protection board not work to reduce static electricity. Discharge energy, so that the lithium battery is stored for a little longer. Therefore, the design requires charging activation.

The field effect transistor used in the protection board of lithium battery used as a protection element. The circuit specially designed to ensure that the battery not reconnected to the circuit when it is abnormal. The method is that the power supply of the control part of the protection circuit powered after the protection of field effect transistor, and the circuit only works after the protection tube normally turned on. Therefore, after the first use or after the protection has generated, the protection circuit cannot work because the power of the subsequent circuit is disconnected and the circuit has no power. There is no output from the battery. At this time, only the battery connected to the charger, the charger used to supply power to the control circuit of the protection circuit, the control part powered, and the battery can used normally.

How to activate the protection board of lithium battery

If the protection board activated after the current limit protection, it may need to activate by charging or after the load is completely disconnected, it is relatively troublesome, but you can also short-circuit B- (battery negative) and P- (discharge negative). The protection will released. Remember to avoid carrying a large load when you touch it shortly (for example, turn it all the time), otherwise, it may cause many sparks. The root cause is the large differential pressure across the MOS after protection. The short touch is to reset the DS level of the discharge MOS to 0V and the protection released at this moment.

Note: It should be almost same for most of boards, even if some do not work, this will not cause damage to board.

The page contains the contents of the machine translation.