原 文Title：RAPID CHARGE SYSTEM FOR LEAD-ACID BATTERY OF SOLAR ENERGY STREET LIGHT BASED ON SINGLE-CHIP MICROCOMPUTER1. IntroductionOur country is very rich in solar energy resources and the utilization of solar energy heat is one of the technologies that are of the highest commercial degree and the most universal application in new and renewable energy resources. Under the initiative of building saving society, the solar energy electro-optic illumination is our countrys realistic choice under the existing national condition and it reduces the expenditures of municipal administration on street lamp to a certain extent. Especially in the newly-built urban road section and remote border district that has difficulty in using electricity, it is of the strongest promotion and is taken seriously by Finance department; it is honored as the 21st centurys green project.2. The basic theory of battery chargingIn the mid-1960s, American scientist Mas has done the massive experimental study to the charging-up process of ringent accumulator cell, and proposed acceptable charging curve taken by the accumulator by the lowest gas efficiency for premise, the curve function is i = I 0 e . The experiment indicated that if the charging current changes according to this curve,it may reduce the duration of charging greatly, and has not affect on batterys capacity and its life, thus it had established research direction to the method of the fast charging. is called the curve the best charge pattern in principle.It May see that the initial charging current is very big from the Mas curve, but weakens very quickly. The primary cause is that it comes into being the phenomenon of polarization during the process of charging. The phenomenon of polarization is refers to that the interior the sealed accumulator has produced the oxygen and the hydrogen during its process of charging, when the oxygen cannot be absorbed promptly, then it piles up on the positive plate, enlarge the pressure of the interior of battery, the batterys temperature rises, reduces positive plates area simultaneously, performance by the increase of interior resistance. The polarization can affect the speed and the quality of charging, and even reduce the life of accumulator. Therefore, its important to develop fast charge system of battery whose performance is fine and movement is reliable. By Not affecting the service life of accumulator as far as possible for premise, it hoped that it can fill the battery capacity sufficiently adopting the biggest charging current in a short time,and the battery neither produces too much gases nor causes the interior hyperpyrexia during the process.3. Solar street light systemIn the solar streetlight system, accumulators charging source is from the solar cell, the change of climate and the users excessive using electricity are very easy to cause the accumulator over-discharge, and therefore the normal works guarantee rate of the solar streetlight is lower than the situation of alternating current by far. If the Lead-acid battery is in the state of over-discharge during use process, then the accumulators life will reduce greatly. Otherwise, if the accumulator cell has been in the use process floats the charge or the shallow discharge condition, then accumulator cells service life will lengthen greatly, even lengthen one more time. Therefore, the function of the charging and discharging control system is obvious in the streetlight system merely relies on the solar cell for the battery charging, its performance has decided accumulators performance, systems reliability and systems cost directly.3.1 pulse charging methodThe theoretical base of pulse fast charge method is by superimposing certain frequency, width and high negative pulse or midway stops for a short time during the charge, makes the lead ion participates in the response produce Pb by dissolving PbS04 and PbO2 with enough time and enhances its density, also makes the procreant H+ and HS04- ion put aside with enough time from the surface of electrode. Its synthetical effect is to reduce the polarization of the accumulators concentration, permit to enlarge the charging current, reduce the charging time.Because the phenomenon of polarization is often not obvious during the initial period of charging ,it may adopt big electric current 0.81 time of rated capacity to carry on the constant-current charge, makes the accumulator charging attain to the 50%60% rated capacity in a short time. Stop to charge when the single standard voltage of accumulator rises to 2.4V, the water starts to decompose and micro air emits (about is 25 milliseconds). In order to eliminate the electric charge accumulation of the electrochemistry polarization and the gas which forms in the pore of pole plate, after stopping sufficiently, Making the accumulator through one big current pulse whose direction is opposite to charge by discharging after stopping charging, the