Charging limit voltage 4.2V is the current use of most lithium-ion batteries are in use of the charging limit voltage, or safe charging voltage, theoretically can be unlimited charge, charging to 4.2V lithium is safe, voltage exceeds 4.2V, lithium safety begins to decrease with the increase in voltage, the higher the voltage, the more dangerous the battery, easy to fire and explosion.
A good lithium battery can withstand a voltage of 4.8-5.0V without fire or explosion. It is almost possible to explode at 4.5V, but 4.2V is basically safe.
Therefore, the conventional charging limit voltage of lithium batteries is 4.2V, and some high-capacity batteries also have a charging limit voltage of 4.35V.
At present, a battery with a charging voltage of 5.0V has been developed through material modification.
The battery standard voltage is also the discharge platform voltage, in the discharge process, the beginning and the end is the voltage drop is relatively fast, and the middle section of the discharge voltage change is relatively gentle, the voltage change is relatively gentle part of the battery discharge platform voltage, generally different materials of lithium battery discharge platform voltage and standard voltage is different, lithium cobalt acid system standard voltage is 3.7V, The standard voltage of lithium ferrous phosphate system is 3.2V, and the standard discharge voltage of ternary system is 3.6V. The charger voltage is what the buddy on the first floor above said: because the wires and circuit boards have resistance, and the diodes have a voltage drop of 0.7 volts, so it adds up to about 5 volts
The charging standard of rechargeable batteries is to charge according to the voltage and current on the charger label.
1. The charging standard is set according to the voltage and current of the charger, following the principles of standard charging and safety, stability and efficiency. 2. The voltage and current of the charger need to match the rated voltage and current of the charging battery to make full use of the energy of the charger and ensure the safety and sufficient energy of the battery.
3. When charging the battery, pay attention to the change of temperature to avoid overcharging, undercharging or overheating, so as to extend the service life of the battery.
In accordance with IEC standards and national standards, nickel-cadmium and nickel-metal hydride batteries under the condition of 20±50C, at 0.1C charging for 16 hours after discharging at 0.2C to 1.0V, the power released is the rated capacity of the battery, expressed in C; Lithium-ion battery at room temperature, constant current (1C), constant voltage (4.2V) after charging for 3 hours, and then discharged at 0.2C to 2.75V, the power released is the rated capacity of the battery. The unit of battery capacity is mah and Ah (1Ah=1000mAh).
1, the working principle of the charger: First of all, AC220 voltage through the fuse, NTC and EMI filter rectifier filter conversion to about 300V DC voltage, through the start resistor to provide 3842(7 pin) initial working voltage, driving the MOS tube switch action, the switch transformer in the MOS tube switch action, will continue to store - - gt; Release, and make the output winding induced by the electric energy through the rectifier filter output DC voltage, by sampling to 431 or opamp control optocoupler signal feedback to 3842 pin 1 or pin 2, control 3842 output (pin 6) duty ratio, in order to achieve a stable output voltage value.
2, there are many types of chargers, such as lead-acid battery charger, valve-controlled sealed lead-acid battery testing and monitoring, nickel-cadmium battery charger, nickel-metal hydride battery charger, lithium-ion battery charger, portable electronic device lithium-ion battery charger, lithium-ion battery protection circuit charger, electric vehicle battery charger, car charger, etc.
1. Charging standards for rechargeable batteries exist. 2. Charging standard refers to the set value that needs to be reached when the battery is charged, usually referring to the battery charging voltage, current and time and other parameters. 3. Different types of batteries, their charging standards are not the same, such as lithium-ion batteries, nickel-metal hydride batteries, etc., so you need to understand the charging standards of the battery before charging, otherwise it may cause damage to the battery, thereby affecting the life and performance of the battery.
The standard charge is 1\/10 of the battery's capacity. The 550MAH is charged with 55MA of current. The voltage limit is 3V stop. Otherwise it will overcharge. It should be 2 nickel-metal hydride batteries in series 1.2V×2. The charging time can be known by monitoring the voltage with a voltmeter. The above is my answer content hope the above answer can help you