Please check the battery capacity before connecting the AC adapter. If the battery capacity is higher than 90%, the system won’t start charging the battery. This is to avoid the loss of battery life span from constantly charged and uncharged, it’s a normal battery charging behavior. *The value of setting capacity (%) to start charging battery is usually located between 90 – 95% and the actual number may differ by models. 

This information applies to the EVO 15-S and NT-15S