As shown in FIG lithium battery is a constant current charging control board, the figure Q1, R1, W1, TL431 composition precision adjustable voltage regulator circuit. Q2, W2, R
2 constitute an adjustable constant current circuit. Q3, R3, R4, R5, LED charging indicator circuit. With a rechargeable lithium battery voltage is gradually increased, the charging current will gradually decrease, decreasing the voltage drop on R4 After the battery is fully charged, and ultimately ended Q3, LED goes out, the battery can in order to ensure adequate, please extinguish lights after 1 to 2 hours to continue to charge, the need Q2, Q3 appropriately sized heat sink mounted when used.