Batterie 12 V (EFB, AGM) et alternateur : test de tension au repos, démarrage à froid et charge
Tension au repos vs état de charge (SoC), chute de tension minimale au démarrage, charge pilotée et règles de remplacement EFB/AGM.
| 100% Resting Voltage (12h rest) | 12.65–12.70 V (Flooded) · 12.80–12.90 V (AGM) |
|---|---|
| Discharged Threshold (< 50%) | ≤ 12.20 V resting (sulfation risk begins) |
| Minimum Cranking Voltage | ≥ 9.6 V at battery posts during starter engagement |
| Alternator Charging Range | 13.8–14.7 V (Smart BMS: 12.8–14.9 V) |
1. Never Downgrade an Start-Stop AGM or EFB Battery
Vehicles equipped with automatic Start-Stop and regenerative braking deceleration use Absorbent Glass Mat (AGM) or Enhanced Flooded Battery (EFB) chemistry. Replacing an AGM battery with a conventional flooded battery leads to rapid plate shedding within 6–12 months. Always register the new battery in the BMS if equipped.
2. Parasitic Draw Limit After Module Sleep
After locking the vehicle and waiting 20–40 minutes for CAN-bus modules to enter sleep mode, steady-state parasitic current draw should not exceed 20–50 mA (0.02–0.05 A). Draws above 80 mA will drain a 60 Ah battery over a long weekend.