cannot
buds2 supports fast charging. The Samsung Buds2 has a charging case with a standard input charging voltage of 5 volts and a maximum input current of 0.3 amps. Therefore, it is completely safe and feasible to charge them with an 18W fast charger.
You can't. The Samsung Galaxy Buds2 charging case will be equipped with a 500mAh battery, each headset will be equipped with a 60mAh battery, the charging case will support 2.5W charging, and the headset will be charged at 0.6W.