Frequently Asked Questions	Description of the problem
Engine does not restart after red light	After the vehicle stops, the engine does not start automatically when the brake is released or the accelerator is pressed.
Start-stop system disabled	The dashboard displays “Start-Stop System Unavailable,” and buttons are unresponsive.
Frequent low battery warnings	Frequent low battery warnings, or even failure to start the vehicle.
Premature battery failure	Severe battery depletion occurs in less than a year.

Root cause analysis

Natural capacity degradation / charging system malfunction / incompatible Battery Management System (BMS).

Start-stop vehicles can experience 3-10 times more charge-discharge cycles in the same amount of time than conventional batteries.

Engine shutdowns and restarts consume significant amounts of electricity, and the battery-powered air conditioning, audio system, and other components place a significantly higher load on the vehicle than conventional ones.

Installing the wrong battery type in a start-stop vehicle can lead to premature battery failure and may trigger fault codes in the Battery Management System (BMS).

Solution

Battery Type	Applicable Scenarios	Key Advantages
EFB (Enhanced Flooded Battery)	Entry-level start-stop vehicles (without regenerative braking)	Cycle life is more than twice that of traditional batteries; excellent thermal stability, suitable for the high-temperature environment of engine compartments.
AGM (Adsorption-Modulated Glass Fiber Separator)	Advanced start-stop vehicles, energy recovery systems	Cycle life is more than three times that of traditional batteries; higher cold start current (CCA); sealed and maintenance-free.

In new vehicles equipped with start-stop technology, AGM batteries account for approximately 70%. AGM batteries have a cycle life of approximately 3000 cycles, while EFB batteries have approximately 2000 cycles.Key point: After replacement, the new battery must be registered in the BMS to recalibrate the charging system. Furthermore, AGM batteries must be replaced with AGM batteries, and EFB batteries must be replaced with EFB batteries; they cannot be mixed.

Technical Principles and Data Support Cyclic Load: It is estimated that vehicles equipped with automatic start-stop function will start three to five times more often than vehicles without this function, and the cycle demand of the battery is 5 to 10 times that of conventional vehicles.

BMS Matching: Most start-stop vehicles require battery registration after battery replacement to allow the computer to re-recognize the new battery’s parameters; otherwise, charging strategies and start-stop functions may be affected.

Replacement Recommendation: Only batteries of identical technology types (AGM→AGM, EFB→EFB) can operate reliably in the start-stop system; mixing different technologies can lead to fault codes, abnormal charging, and even safety risks.