1. Voltage protection of the phone battery protection board
: overcharge and over discharge, which should be changed according to different battery materials. This seems simple, but in terms of details, it is still experienced and learned.
For overcharge protection, in our past, the protection voltage of a single battery will be 50 ~ 150mV higher than the full battery voltage. But the power battery is different. If you want to prolong the battery life, your protection voltage should choose the full voltage of the battery, or even lower than this voltage. For example, manganese lithium battery, you can choose 4.18v ~ 4.2V. Because it is multi string, the lifetime capacity of the whole battery pack is mainly based on the battery with the lowest capacity. Those with small capacity always work at high current and high voltage, so the attenuation is accelerated. The large capacity is filled and placed gently every time, and the natural attenuation is much slower. In order to make the battery with small capacity charge and discharge with care, the overcharge protection voltage point should not be too high. This protection delay can achieve 1s to prevent the influence of pulse, so as to protect.
(phone battery protection board)
Over discharge protection is also related to the material of the battery. For example, manganese lithium battery is generally selected at 2.8V ~ 3.0V. Try to be slightly higher than the over discharge voltage of its single battery. Because the discharge characteristics of domestic batteries are completely different when the battery voltage is lower than 3.3V, so the battery is protected in advance, which is a good protection for the service life of the battery.
The general point is to try to make every battery work in light charge and light down, which must be a help to the service life of the battery.
The delay time of over discharge protection should be changed according to different loads. For example, for electric tools, the starting current is generally above 10C, so the battery voltage will be pulled to the over discharge voltage point in a short time to protect. The battery cannot be operated at this time. This is noteworthy.(phone battery protection board)