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Thin, large-capacity, long service life, these are the outstanding characteristics of lithium batteries. For this reason, lithium-ion laptop battery was quickly replaced by nickel-metal hydride and nickel cadmium batteries role as notebook computers, portable products, the preferred range of equipment. Near Period, discovered in a row of notebook battery explosion, the notebook battery time and again to the air waves, lingering fear that end users, lithium batteries in the end is the source of power or time bomb?

The study found the battery on fire mystery

In general, the current notebook lithium battery pack itself with better protection.

It not only by the series / parallel multiple batteries, also contains its own circuit substrates two modules: the protection of Circuit substrate (Protection PCB) module and the Smart Battery Gauge Board module, a set of batteries to protect its design, including the first-class Protection of the IC (to prevent the battery charge-off, let-off, short-circuit), the second-level protection IC (for the second time to prevent over-voltage), fuses, LED direction, temperature regulation, and other components.

In the multi-level protection, even in the power charger, notebook unusual, notebook battery can only be changed automatically to protect the state if the situation is not serious, often re-plug in after normal work can not Will be an explosion. Notebook battery exploded in the face of serious facts, ask the reporter of Xinhua professionals as well as a well-known manufacturers of design engineers.

According to the analysis of lithium batteries from Wu Waihu explosion or short circuit had caused sufficient, the biggest is the possibility of a lithium powerbook battery at the time of manufacture, because the manufacturing process itself flawed, because the product can occur at any time there is a potential safety problems, such as should be The insulation between the metal poles of dust or copper foil and aluminum foil pierced the burr diaphragm, causing a short circuit, such as micro. The former is the most serious, as a direct result of a large number of short-circuit and heat production, resulting in vaporization of some of the electrolyte, the battery case Stretch.

In addition, there is a rather exceptional power charger or laptop computers due to special reasons, lithium batteries to provide instant high-voltage / current strong lead over the serious charge, such as the charging voltage 12.6V by the sudden rise to 12.9V Or more, this time there will be a charge of high-flow generation, the internal battery circuit moves to cut off the charge current, but some of the lithium battery over-voltage and over-current protection design is very weak, which may result in damage to the IC to protect the battery, So that the notebook battery to make the protection and the damage after a charge-off around the needle-chip lithium metal crystallization of the piercing point resulted in a number of micro-short-circuit, causing the battery temperature gradually increased until the final battery explosion, the fire occurred, This is a lot of notebook battery “hot” the main reason.

Add a layer of protective cover

At present, the mechanisms for the protection of the A1078  from the point of view, rechargeable battery pack in front of some of the traditional chip makers are mostly provided by the program play a precise control of charge voltage and charge current role in the over-voltage and over-current control does not provide corresponding Solutions. In this way, for the protection of the battery pack is entirely dependent on the battery itself, such as the charge-off protection, over-discharge protection, charge-off protection, have put current protection, over-temperature protection and so forth.

Protection in place as a result of the need to prevent first-class IC protection MOSFET failure or short-circuit caused by over-voltage fault, so the second-level protection IC generally is considered to be the protection of the battery pack is the last line of defense. In this connection, e-convex (O2 Micro) Hong Shi Zhen-product manager expressed different views, he believes that the protection of the battery can be moved forward, through the charger attached to the control functions to achieve the detection and control of battery charging action, which will no doubt further enhance the level of protection, The use of lithium batteries on the protection of security.

To this end, O2 Micro in power management for portable devices developed by Cool Charge solutions, the integration of a project called Cool Battery Technology A1148  protection technology, which is the main feature of a traditional charger generally do not have the OVP (over Voltage Protection) and OCP (Over Current Protection) function to protect the two batteries, the technology has been Cool Charge IC chip embedded in them.

Cool Charge IC chip used, the power charger to a large extent will assume the responsibility to protect the battery. Cool Charge IC subject to the control of the charger in comparison with the traditional design (see Figure 1), needed to significantly reduce the external device And eliminate the need for Q3 and Q4 part of the design, reducing the failure rate. Retained in the Q1 and Q2 (to improve the original design of components) between, Cool Charge IC set up a detection point, the factory settings, the Detection of point voltage and current settings are slightly smaller than the battery manufacturers to set safety requirements. In this way, in charge voltage or current Cool Charge IC beyond the security settings of voltage or current value, IC control Q2 off, the first battery Protective effect before the cut off charge; from the frequency of detection, protection, detection of battery time for the millisecond level, and through the chip to detect, you can easily achieve the level of seconds per million, can be very high The frequency of detection in a row, thus realizing the first step in the protection of the PowerBook G3 battery  pack.