Can the battery be charged directly by the switching power supply?
I can responsibly tell you that you cannot charge directly!
If two lithium batteries are connected in series to form 7.2V, the maximum charging capacity is 3.6 * 1.16=8.3V
If it is a lead-acid battery, it can be charged to a maximum of 7.2 * 1.2=8.6v
Although the original charger output 12V voltage, which may be no-load floating voltage, it will come down as soon as the battery is connected. Your battery is 2000mah, and the charging current is generally between 2000/10-4=200-500ma, which is safe. Although the original charger has a nominal output of 800ma, 12.8V, the power of switch power supplies on the market today is all virtual, and a discount should be made. In fact, the safest current is 1/10=200ma, which is the most fully charged and the battery life is also the longest, It's just that the charging time is longer. So, the output voltage of 12V on your switching power supply is too high. Without constant current and voltage reduction, it's impossible to directly charge, and it can really explode
Another possibility is that this appliance comes with a built-in charging circuit, so installing the battery in the appliance can use this 12V switching power supply. There is no need to consider this 0.8V voltage difference, as the current is not related to high. If it is small, it will cause the switching power supply to heat up (just try the temperature of the shell by hand) and burn it out
How to quickly charge the phone battery when repairing the power supply
Adjust the voltage to 4.2 and limit the current below 1C. If the current drops to 1/10 of the preset current, it will be fully charged. If you want to fully charge, you can wait until 1/20
Of course, you can also play with manual pulses. After the constant voltage light is on, manually adjust the voltage to 4.3. After two seconds, lower it back and wait for five seconds to adjust it to 4.3. If it's not a CNC power supply, don't play with it. The maintenance power supply for ordinary multi turn potentiometer voltage regulation is prone to overvoltage, triggering protection board protection~~
In fact, manual pulse, roughly equivalent to the charging method of 1879, can effectively reduce charging time, but it may damage the battery. After all, during the charging process, the voltage exceeds 4.2, and batteries with high internal resistance may generate heat using this method~~
This is not activation. Lithium battery activation only requires a few normal cycles, just pulse charging. Many models of NOKIA phones use the MAX1879 single lithium charging chip in this way, but the control is more complex, including pre charging, maximum time limit, PWM modulation, and so on
