Smart #3 Brabus Mk1

The smartOS infotainment system based on Qualcomm Snapdragon has been a persistent source of frustration. Owners report screen freezes, navigation losing turn-by-turn directions, and the Hello Smart companion app being unreliable with delayed data or spontaneous logouts. OTA updates have been problematic: version 1.5.0 was suspended entirely and required dealer visits to install. Some owners waited weeks for dealers to resolve update failures. While most software issues are resolved under warranty at no cost, out-of-warranty dealer diagnostic visits typically cost around €150-500 depending on the issue. Smart has been releasing incremental updates, but the software remains less polished than established competitors.

This is a design decision rather than a defect, but it affects nearly every owner. Lane-keep assist, speed limit warnings, and other ADAS features automatically reactivate every time the car is started or shifted out of Park. Owners must navigate through touchscreen menus to disable unwanted alerts each drive. A partial workaround exists: the favourites menu allows saving a preferred ADAS configuration and applying it with one tap, but it still requires manual action every time. This is a widely reported frustration across all Smart #1 and #3 models and has not been permanently resolved through software updates as of early 2026.

Like many modern EVs, the Smart #3 Brabus can drain its 12V auxiliary battery if left unplugged for extended periods. The high-voltage battery does not automatically top up the 12V system when the car is off. If the 12V battery dies, the car cannot be unlocked or started normally. Replacement 12V batteries cost €150-400 depending on whether OEM or aftermarket. A quality trickle charger (CTEK recommended) or keeping the car plugged in prevents this issue. The problem is more pronounced with earlier software versions; updates have improved 12V management somewhat.

Smart identified a batch of early Smart #1 vehicles (technical bulletin TBA24005) with high-voltage battery cells showing voltage drops between cells. Smart proactively contacted affected owners through vehicle telemetry monitoring and arranged HV battery replacements under the 8-year battery warranty. The majority of affected cars were in Europe. While the issue primarily targeted 2022-2023 Smart #1 builds, the #3 Brabus shares the same CATL-supplied 66 kWh battery architecture. Under warranty, replacement is free but can take up to 2 months due to parts availability. Post-warranty battery replacement would be extremely expensive (€8,000-15,000), but the 8-year / 200,000 km warranty makes this unlikely for most used buyers. Later production batches do not appear to be affected.

Forum reports document rattles emerging from various interior locations, particularly the tailgate area (starting around 15,000 km), B-pillar trim, centre steering wheel/airbag area (temperature-dependent), and sunvisor. Dealers have addressed these with tailgate spring replacements, foam dampening material, and suspension component swaps with mixed success. The issue appears more common on early production cars and may be related to the new manufacturing facility in China still refining build tolerances. Under warranty, dealer fixes are free. Out of warranty, diagnosis and repair typically costs €100-500 depending on the source.

When the battery is cold (typical in European winter conditions), DC fast charging can start as low as 35 kW instead of the rated 150 kW peak, with very slow ramp-up. One owner reported charging from 30% to 55% took 35 minutes in winter conditions. The car has a heat pump and battery preconditioning, but preconditioning must be activated before arriving at the charger for best results. Routing to a fast charger through the navigation system automatically triggers preconditioning on newer software versions. This is a characteristic of all EVs to some degree, but the Smart #3 appears more sensitive than some competitors. There is no repair cost as this is inherent battery chemistry behaviour, but it significantly impacts usability in cold climates.