In addition, the lithium battery of the phone or charger in the battery will automatically stop after charging, there is no nickel electric charger called 10 hours of the so-called "trickle" charge. In other words, if your lithium battery is full, on the charger is also white charge. And none of us can guarantee that the battery charge and discharge protection circuit features never change and the quality of foolproof, so your battery will be long on the edge of danger wandering. This is another reason we oppose the long charge.
Also on some phones, after charging for more than a certain period of time, if you do not remove the charger, then the system not only does not stop charging, will begin discharge - charging cycle. Perhaps the vendor of this practice has its own purpose, but it is obviously unfavorable for the life of the battery and the phone / charger. At the same time, long charging takes a long time, often need to be carried out at night, and the situation in China's power grid, many places at night the voltage is relatively high, and volatile. As already mentioned, lithium battery is very delicate, it is more than nickel in the charge and discharge resistance to fluctuations in the ability of much worse, so this brings additional risk.
In addition, the other can not be ignored is the lithium battery is also not suitable for over-discharge, over discharge on the lithium battery is also very unfavorable. This leads to the following questions.