There are 1 stored owner reports matching the powertrain & transmission leading-label group for the 2021 Mercedes-Benz S-Class in our NHTSA-sourced dataset. These are unverified consumer reports and may not reflect confirmed defects.
This group counts stored reports whose component label starts with one of this site's matching prefixes, ignoring case. Each matching report counts once within the group. Components mentioned later in the label or only in the narrative are not searched. How component counts work
Loaded 1 of 1 matching reports.
Open the full vehicle complaint log (all categories)Issue: STARTER BATTERY Repetitive online and dashboard screen message notices stating, "BATTERY CHARGE Status Critical," at all hours of day and night requesting immediate 30-60-min. of driving or car will not start. Have had to wake up from nightime sleep to drive car in middle of night so it would start the next morning to drive to work. Also, multiple electrical problems related to this issue ensue. Unreliable vehicle start up; too great a demand on electrical system. Vehicle taken in to dealer for service five times in six months since new purchase. Dealership Service Department found battery has malfunction. System restricted. Code stated, ". . . battery voltage may drop significantly under or at 45% due to listed operations on document. Most operations are for using vehicle ignition on (on ignition) and screen operation. Battery can be (can) drop due to using these functions." (See attached documentation.) BATTERY MAINTAINER (CHARGER) should be basic part of vehicle included in purchase price given battery drain on excessive electrical component demand not additional cost for Battery Maintainer (Charger) part and installation.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
NHTSA source checks for this vehicle year
Checks are recorded separately for each dataset, not for the whole page. Dates use UTC. A missing check date does not mean no records exist.
Vehicle import recorded: Aug 31, 2026. This is the stored import date, not confirmation that every source was successfully refreshed.