The invention discloses a serial-parallel conversion and intelligent charging 
system for a lead-acid storage 
battery pack. An intelligent segmental pulse charging technology is provided, the reverse instantaneous 
discharge function of a storage battery is added, the 
vulcanization phenomenon of a battery is reduced, the receiving rate of the battery is increased, the charging speed is increased, and the service life of the battery is prolonged. The 
system consists of a power supply main circuit, a 
control circuit, a simple keyboard and display circuit, an 
energy feedback circuit, a 
battery pack serial-parallel conversion circuit and a temperature measuring circuit, wherein the power supply main circuit consists of a full-bridge 
inverter circuit consisting of a full-bridge rectifying circuit and an IGBT (Insulated Gate Bipolar Translator), and a full-wave rectifying circuit; a C8051F020 singlechip is taken as the core of the 
control circuit; the simple keyboard and display circuit can be used for selectively charging on a peak valley; a 
transformer is taken as the feedback channel of the 
energy feedback circuit; 
discharge energy is stored in a 
filter capacitor. The 
battery pack serial-parallel conversion circuit consists of a three-pole double-throw switch and a 
diode, and a series battery pack adapter is used for charging a parallel battery, thereby solving the problem that all batteries cannot be charged due to damage to a single battery in the battery pack. The 
system is suitable for intelligent charging of electric bicycles in industrial production and civil use.