The protection function of lithium battery is usually completed by the cooperation of the protection circuit board and PTC or TCO and other current devices. The protection board is composed of electronic circuits. It can accurately monitor the voltage of the cell and the current of the charging and discharging circuit at the time of -40℃ to +85℃, and control the on-off of the current circuit immediately. PTC or TCO protects the battery from severe damage at high temperatures.
Protection board usually includes control IC, MOS switch, precision resistance and auxiliary devices NTC, ID memory,PCB and so on. The control IC, in the case of everything normal control MOS switch conduction, so that the cell and external circuit communication, and when the cell voltage or loop current exceeds the specified value, it immediately (tens of milliseconds) control MOS switch off, protect the safety of the cell.
The NTC stands for Negative temperature coefficient. When the ambient temperature rises, the resistance of the NTC decreases. The NTC uses electrical or charging equipment to respond in time and control internal interruptions to stop charging and discharging.
ID memory is usually a single line interface memory, ID is the abbreviation of Identification that means Identification, storage battery type, production date and other information. Can play a product traceability and application restrictions.
PTC stands for Positive Temperature Coefficient. Professional inside usually positive temperature coefficient device referred to as PTC, PTC in battery products can prevent battery high temperature discharge and unsafe large current, according to the battery voltage, current density characteristics and application environment, there are special requirements for PTC.
PTC is a very important component in the battery component products. It plays an important role in the safety of the battery. Its performance and quality are also an important factor in the performance and quality of the battery.
Threatening the single cell protection, protect board design is relatively simple, high technical, such as the need to pay attention to the voltage of power battery protection board design platform, power battery in use is often requires a great platform for voltage, so as far as possible when design protection board make protection board does not affect batteries discharge voltage, so to control IC, The requirements of precision resistors and other components will be very high, generally domestic IC can meet the requirements of most products, especially imported products can be used, the current sampling resistance needs to use JEPSUN Fast ratio letter resistance, to meet the requirements of high precision, low temperature coefficient, no induction and so on. For the design of multi-cell protection board, there are higher technical requirements, according to different needs, the design of the complex degree of different products.
Main technical functions:
1, over charge protection 2, over discharge protection 3, over current, short circuit protection
Solution after mobile phone battery startup protection (from the network) :
1, with the original direct charging on the phone, the protection circuit of the battery protection board will be automatically opened.
2. The positive and negative electrodes of the battery are short-circuited instantly, and the spark on the electrode sheet is on the line. Try several times, and then use direct charging.
3, find a 5V dc, with positive and negative electrode touch the positive and negative electrode of the battery, try several times, and then use the original charger charge.