Author ：Iflowpower – Portable Power Station Supplier
You can use different charging methods to charge. When selecting the most suitable charging method, use frequency, discharge ratio, use. The chart below will discuss different charging methods in detail.
Constant current charging When constant current charging, the battery has high charging efficiency. It can be convenient to determine whether the charging is aborted according to charging time, or change the number of batteries. The voltage of external power supplies will usually fluctuate, and a constant current supply is required when charging.
However, due to the price of DC constant current power supply, the quasi-flow charging is often used during charging. Quasi-constant current charging In this method, the internal blocking of the new circuit occurs in this method. The resistance value is adjusted according to the current at the end of the charging, so that the current does not exceed the specified value.
Due to the simple circuit, the cost is low, this method is widely used in charging. At the same time, the equipment with AC and DC circuits do not have additional chargers, and the DC circuit above it can be used to charge the battery. Constant voltage charging When charging the battery, the voltage across the battery determines the charging current.
In this charging mode, the current current is high, and the final current will become low. As the voltage fluctuates, the charging current should be set to the maximum output value when the power supply voltage is highest. In addition, in such a charging method, the charging voltage will fall after reaching the peak, and the charging current is changed, which will cause the battery temperature rise.
Further, as the battery temperature increases, the voltage drops, causing a so-called thermal out-of control, impairing the performance of the battery. Therefore, Huanyu is not recommended to use constant voltage charging method. Trickle mode In the floating method, the battery is charged at a very small current between C / 30 to C / 20, and keeps full-charged statement.
Floating method for fire alarm and emergency light. Figure 6 is an example of a floating manner charging. After the floating method of the ring, the battery is connected in parallel, connected to the charging circuit.
Under normal circumstances, the current is passed through the load, and only the battery is discharged only when the load becomes large or after the power is stopped. In this way, charging current is determined by the mode of use. It is usually used where emergency power, spare power or electronic watch, etc.
Figure 7 is a simple schematic illustration of this manner. The resistance variable in the figure. In the stage charging in the stage, the initial charging current is higher.
When the battery voltage reaches the control point, the current is turbulent, for example, from 0.2C to 0.02C.
This is the most ideal charging method, but the disadvantage is that the complicated circuit is expensive. In addition, the monitoring of the voltage of the control point is also a problem. Figure 8 is a simple schematic of this manner.
Charging circuitry with solar cell charging this charging circuit is the easiest. Use a one-way diode to achieve high charging efficiency. The outdoor temperature changes great, it is recommended to use an improved solar charging circuit, so that the temperature change does not exceed the initial set value.
The influence of the output current of solar cells. Figure 10 illustrates the relationship between the output current of the solar cell and the daily different time. When the weather is overcast, charging is not sufficient.
However, solar cells need to consider the maximum output current from sunny at sunny days does not exceed the specified current. Fast charging When charging the battery with a large current, an additional control circuitry needs to be used. It detects battery voltage and battery temperature at the end of charging, and stop charging.
(1) Battery voltage detection passes through the auxiliary circuit, detecting the battery voltage and converts current to small current charging at the end of the high current charging. Since the preset adjacent voltage must be lower than the charging peak voltage, in order to ensure the charging capacity, the auxiliary charging of small currents must be considered. (2) -ΔV control system In this system, charging current is controlled by voltage drop in the final stage of charging.
Fig. 13 illustrates a brief situation of the -ΔV control system uses a voltage detection system. However, when the peak is determined, the ambient temperature compensation circuit can not consider.
When the voltage drop reaches a predetermined value, the charging current is cut off. (3) Battery temperature detection In the final stage of charging, the negative electrode has an oxygen compound reaction, so that the battery temperature increases. To control the charging current, the temperature sensor or thermocouple detection battery temperature can be placed outside the battery steel shell.
At this point, the battery is already in the pre-charge state, which requires a battery with a certain amount of energy. Figure 14 is a schematic. This circuit is simple and cost-effective.
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