No hidden fees. The total amount on the FOB/CIF invoice is the final amount. We rely on professional supply chain operations to earn a reasonable margin and do not allow any sales personnel to privately request kickbacks or service fees from you.

Obtaining precise internal resistance at different SOC levels requires disassembling the battery pack and connecting it to a professional charge-discharge cabinet for several days of cycling tests. This is beyond the scope of non-destructive used car inspections; we only provide real-time estimated internal resistance data based on OBD port readings.

We use two steps: 1. Insert a medical-grade endoscope through the spark plug hole to visually inspect cylinder wall scratches and carbon buildup on the piston top; 2. Extract an engine oil sample to check for large metal debris or emulsification (caused by coolant leakage).