66w car charger will not charge the mobile phone, charging the mobile phone is mainly to see the stability of 5V charging voltage, requiring 5V to always remain stable, unrelated to the power of the target, the new mobile phone has a fast charging function, the charging current required is relatively large, the corresponding power is also large, the charging current provided by the car charger wattage is larger, the voltage is also 5V, As long as a mobile phone is charged, there is generally no problem, but if two mobile phones are charged, the charger may be hot, and the voltage conversion module inside will pose a threat to the mobile phone if the breakdown and short circuit are caused by high temperature.