BMW AUX Li-Ion 12V Battery Repair Service

Description Modern BMW vehicles equipped with 48V Mild Hybrid systems use small Li-Ion AUX batteries responsible for system stabilization, wake-up logic, start/stop support and communication backup functions. A very common failure scenario is: Battery shows 0V on output terminals Vehicle reports random AUX battery DTC faults Vehicle enters warning or limited operation mode AUX battery appears “dead” even though cells are still recoverable In many cases the issue is not physically damaged cells, but BMS protection lock caused by deep discharge or internal shutdown logic. EV Clinic offers professional diagnostics, recovery and repair service for BMW AUX Li-Ion batteries. Our process includes: Safe battery opening procedure Cell voltage analysis Controlled manual cell recovery BMS hard reset and wake-up procedure Functional output testing Internal inspection for overheating or corrosion Final validation under load conditions IMPORTANT: In many cases processor programming or BMS replacement is NOT required. Supported issues: 0V output “Aged auxiliary battery” Unknown DTC faults Wake-up failure Sleep/protection lock Intermittent AUX battery operation Common supported part numbers: 61215B3F325 61215A8D7E0 61215A4AF23 61215A46EA1 61215A38DE7 612154078B0 61219857516 61219442935 61219857095 61219857160 Vehicle compatibility includes selected: BMW G-Series platforms BMW Mild Hybrid (MHEV) vehicles BMW 48V systems using AUX Li-Ion support battery architecture Service includes: Diagnostic report Functional testing Recovery attempt Repair consultation EVC engineering evaluation NOTE: Not all batteries are recoverable. Batteries with physically damaged cells, water ingress, thermal damage or severe corrosion may require module replacement. For shipment instructions or availability contact: ← BackThank you for your response. ✨ Name(required) Email(required) Website Message Submit Δ Like this:Like Loading…