The water loss of the Colin pulse is one-third of that of the ordinary charger. If the water loss is small, the voltage difference of the battery pack will be small. Conversely, if the water loss is large, the voltage difference of the battery pack is large. As the amount of water loss increases, the vulcanization will also increase, and the ordinary charger does not remove the vulcanization function, so the battery pack is seriously out of balance. When the Colin pulse is charged, the amount of water loss is small, and the voltage difference of the battery pack is also small. When the battery is vulcanized, it can be removed by pulse, so that the whole battery tends to be balanced. Colin pulse constant current stage of the current is large, the role is: 1, fast charging, saving charging time; 2, activate the battery plate, eliminate battery passivation, restore battery capacity, so that the entire battery capacity tends to balance. In the drip filling phase, the effect of the current bifurcation can be eliminated, and the undercharged battery is dripped, and automatically turned off after being fully charged, reducing water decomposition and maintaining the balance of the battery pack.