How many watts should a car phone charger be?

When selecting the power rating of a car phone charger, comprehensive consideration should be given to device compatibility, charging efficiency, and safety. Modern smartphones typically support 15W to 20W fast-charging protocols (such as USB PD or QC3.0), while some high-end models can accommodate power above 30W. Note that the charger should incorporate safety features including overvoltage protection and temperature control, with priority given to SIRIM-certified products to ensure compliance with local 240V voltage standards. Additionally, an 18W dual-USB charger can simultaneously meet charging demands for both phones and tablets, while avoiding battery degradation or electrical faults caused by substandard products.