Talking about power lithium battery protection projects
Mar 31, 2023
Current protection: It should be manifested in the operating current and overcurrent to disopen the switch MOS, and then protect the battery pack or load. If the damage of the MOS tube rises in temperature, its heating is also the size of the current and its own internal resistance to choose, of course, small current, has no effect on MOS, but large current, this should be done well, in the rated current, small current below 10A, we can directly use voltage to drive MOS tube.
Large current is to add drive and give MOS a large driving current. The following MOS tube driver talks about the working current, in the planning, the MOS tube can not exist 0.3W power. Accounting formula: I2*R/N. R is the internal resistance of MOS, and N is the number of MOS. Assuming high power, MOS will have a temperature rise of more than 25 degrees, and because they are all sealed, even if there is a heat sink, the temperature will still rise when working for a long time, because it is not dissipating heat. Of course, the MOS tube is no problem, the problem is that his heat will affect the battery, and the protection board is placed with the battery.
Voltage protection overcharge, overdischarge, which is changed according to the data of the battery, which seems to be brief, but in terms of details, there is still academic knowledge. Overcharge protection, in our previous single-cell battery protection voltage will be 50~150mV higher than the battery charge. However, the power battery is different, assuming that if you want to extend the battery life, your protection voltage will choose the charging voltage of the battery, resulting in a lower voltage than this voltage.
