How notebook battery explosion-proof
Thin, large-capacity, long service life, these are the outstanding characteristics of lithium batteries. For this reason, lithium-ion FRU 92P1121
was quickly replaced by nickel-metal hydride and nickel cadmium 40Y6799 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 FRU 92P1139 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 40Y6793 , FRU 92P1125 from Wu Waihu explosion or short circuit had caused sufficient, the biggest is the possibility of a lithium FRU 92P1141 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 glitch is a lack of short circuits caused by 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, in-house circuit the battery charge current should be cut off action, but some of the lithium FRU 92P1137 over-voltage, over-current protection design is very weak, which may result in damage to the ThinkPad Z61t protection IC, 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 battery from the point of view, rechargeable 02K6651 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 on.
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 will generally be considered is the protection of the 02K6928 , 02K6620 , 02K7039 pack in the last line of defense. In this connection, e-convex (O2 Micro) Hong Shi Zhen product manager, said the different views, in his view, for the protection of the battery pack can be moved forward through additional controls on the charger to realize 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 battery protection technology, which is the main feature of a traditional general Chargers do not have 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, take on 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. Preserved 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 ThinkPad X60 , FRU 92P1167 manufacturers to set safety requirements. In this way, in charge voltage or current beyond the Cool Charge IC set up security after the 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 ThinkPad Z60t 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 battery pack.