Is there any current difference in different USB charging cable?
First, the commercially available USB charger, whether it is 250mA, 400mA, 500mA or 1000mA, only represents the current output capability of the charger, and has nothing to do with the large and small charging of mp4. As for the "lights turn from red to green", the output current tends to zero.
Second, Inside the mp4 player, there is a charging control circuit. The charging current of its battery is controlled by this circuit. When the charging is completed, the current is reduced to the "turbulent" state, and the indicator light on the charger will naturally turn green. As for "the higher the current, the shorter the charging time. But the damage to the battery is greater" is wrong.
Third, the commercially available USB chargers generally output 5V voltage. The mp4 rechargeable battery is also mostly 3.6V. So the USB charging cable current is controlled by the charger. This has been reliably demonstrated from the side.