1. We see the manufacturers is formal or not. Normal product, there must be a Chinese trademark and manufacturers details, and factory address and telephone number are printed on the packaging. If don't have, the quality without assurance.
2. We can see the technical parameters. The following five technical parameters are the key to measure the quality of a car inverter
A.The maximum error of output voltage when the load rating is AC220V±1%. Voltage error value is smaller, the quality of car inverter is better.
B.When the load is unstable, the output voltage instantaneous maximum error is AC220V plus or minus 4%. When the load is unstable, the output voltage instantaneous maximum error is more bigger, the quality is more lower.
C. The Operating frequency is 50Hz±0.05Hz. The working frequency error of the product more smaller, the quality is better.
D. Output waveform: Sine wave, modified sine wave. When the output waveform closer sine wave, the products quality is better.
E. Inductive load continuous power is 300 w. The greater of the inductive load means the products quality is better.