\"Slow charge\" refers to low current charging, usually using a micro USB plug to input a small current of 5V into the battery to slow down the battery's power consumption, in this case, it can save time. Slow charge is generally used to charge electric vehicles, mobile phones, tablets and other electronic products. It can reduce the charging time, but also to ensure that the battery will not be excessive power consumption, to avoid battery damage.
The charge is relatively slow, but the advantage is that the battery is better protected