due to the influence of natural climate, wind power generation and photovoltaic power generation systems fluctuate at random. in order to meet the requirements of stable and reliable operation of the system and improve the stability of the system, it is an important way to ensure the normal operation of wind power generation system and photovoltaic power generation system be equipped with a certain capacity of energy storage equipment. Battery is an ideal energy storage device, which is the most widely used energy storage device in power system at present. however, given the cost and technological maturity of batteries and wind power systems, lead-acid batteries are currently commonly used for energy storage [1]. Because of the large proportion of battery cost in the cost of wind power system, the service life of battery has become a bottleneck restricting the wide application of wind power system. charge and discharge current and battery overcharge phenomenon are two main factors affecting battery life [2]. How to charge the battery efficiently, quickly and losslessly has always been a great concern in the battery industry, and it is also a very important content in battery use and maintenance. Most batteries don't run out; they' re "dead ". The performance of charging equipment plays an important role in the life of the battery. Therefore, how to improve charging technology and charging device has been an important topic in the field of battery.