2026-07-22 · 5 min read
Mercedes-Benz S-Class — 发电机
S-Class Dual Battery and Alternator System
W222 S-Class uses a dual battery system — main AGM battery under the boot floor and an auxiliary battery in the engine bay. The smart alternator charges both via a battery control module (BCM). W223 M256 uses a 48V ISG instead of a conventional alternator for the main charging. Fault diagnosis requires XENTRY live data on both battery voltages and the ISG current output.
Cost
- W222 alternator + labour + dual IBS reset
- W223 ISG 48V unit+ (specialist)