What Does Shallow Charging and Discharging Mean?
2 Answers
Shallow charging and discharging refers to not fully charging or discharging the battery to its maximum capacity, meaning the battery is neither fully charged nor completely drained. Example: For a battery with a total capacity of 50Ah, using only 20Ah-30Ah of power each time and charging promptly is called shallow charging and discharging; if charging to 50Ah and discharging to 50Ah, it is called full charging and discharging. Battery Charging Notes: When a lithium battery cell is overcharged to a voltage higher than 4.2V, adverse effects begin to occur. The higher the overcharge voltage, the greater the risk. Once the lithium cell voltage exceeds 4.2V, less than half of the lithium atoms remain in the positive electrode material, often causing the storage lattice to collapse, resulting in permanent capacity loss. If charging continues, since the storage lattice of the negative electrode is already filled with lithium atoms.
Shallow charging and discharging means we should avoid always charging the battery to 100% or draining it to 0% when using it. I pay special attention to this when driving an electric vehicle because fully charging or discharging increases the stress on lithium ions, accelerating aging. In practice, I usually set the charging limit to 80% and the discharge limit to 20%, keeping the battery in a comfortable range without excessive strain. Modern electric vehicle systems typically have a BMS (Battery Management System) that automatically regulates the charge to ensure smooth operation. The biggest benefit is extending the battery's lifespan—potentially adding two to three more years of use with ease. It also saves energy, reduces the need for frequent charging, and is environmentally friendly. This practice applies to all lithium-ion battery devices like smartphones and laptops. Don’t underestimate daily maintenance—it adds up to significant savings and eco-friendliness over time.
