USB Phone World Posting Page
Thursday, December 29, 2011
Most users’ familiarity with a large inclusion by the Li-ion battery series, of many laptop batteries of high energy density and wonderful performance doesn’t really seem to eliminate their difficulty in guaranteeing the safety of these batteries. An overcharge of these batteries can lead to a rise of their temperature and a surplus of energy, which will thus have the decomposition of electrolyte turned into the production of gas and arouse the liability of a rise of this battery’s internal pressure to the danger of spontaneous combustion or crack. The decomposition of batteries’ electrolytes, on the contrary, can lead, under circumstances of their overcharge, to such deterioration of their properties and durability as will lend a profound reduction to their being rechargeable.
Most laptop batteries’ protection circuits which, in the event of deterioration of their properties, are designed to ensure the safety of the condition of their overcharge and release of electricity, are made up of the protection IC and two power MOSFETs, the former being employed in the monitoring of their voltages, in case of the translation of the condition of their overcharge and overdischarge into the dangled power MOSFET applied to batteries’ protection. The functions of the protection IC range over overcharge protection, overdischarge protection and overcurrent and short circuit protection.
The majority of the laptop users are complaining about the frequent impossibility of a full charging of batteries that from time to time are even showing signs of damage, the reason for which is due largely to their long use of batteries whose chargeability and excellent performance depend frequently upon their newness or upon their not having been used for very long. And therefore most laptop users are quite concerned about how to maintain and recover the proper functioning of batteries. Activation and radioactivation, both of which can be well suggestive of the process of batteries’ movements from death to life, are perhaps the best names for the condition of batteries’ maintenance.
Some of the laptop batteries’ erroneous actions issuing from the noise produced during their charge and discharge will, moreover, have to be paid close attention to by users, for fear of their misjudgment of these wrong actions to be overcharge protection. And therefore a protraction of time demands to be made shorter than the duration time of the noise. The decomposition of the electrolyte, in the case of batteries’ overdischarge, can make for such deterioration of the properties of the battery as will reduce the times of their charge. An adoption, herewith, of overcharge protection serves to defy the emergence of the phenomenon of batteries’ overdischarge, in order for users’ realization of the real value of their protection functions.
A long use of many of the high quality batteries can often generate their tendency to get old by virtue of exhibition of a strong internal resistance which, at the moment of their charge, causes a rapid rise of the voltage of the two ends. This phenomenon is dangerous which leads often to an erroneous judgment by the charge control circuit that the battery has been fully charged and that its capacity has naturally gone down. It is highly necessary for a bad role of this issue in the sustainability of batteries’ service life to awaken users to keeping tabs on its occurrence.
by: USB Phone World