Smart #5 100 kWh RWD Mk1

The Smart #5 runs the smartOS system shared with the #1 and #3, which has a documented history of software issues. Owners report the infotainment screen occasionally freezing and rebooting, the Hello Smart app losing connection or showing incorrect data, and settings (such as driver assistance preferences) reverting after updates. On the #1 and #3, OTA update 1.3 caused notable regressions including broken scheduled charging and online services disconnects. Smart has been addressing these with incremental OTA updates (version 2.2.0 was rolled out for the #5 in March 2026), but the system remains less polished than established competitors. The cost is typically zero (covered by warranty or OTA fix), though repeated dealer visits for software resets can become inconvenient.

A known issue on the Smart #1 and #3 (same SEA platform family) that may carry over to the #5. The electrically operated flush door handles can fail to retract properly, staying partially extended when parked. This triggers a dashboard warning. On the #1, this was described as affecting all cars up to a certain batch number, and Smart implemented retrospective fixes at ports. The handle mechanism needs complete replacement, as it is not field-serviceable. Under warranty, replacement is free. Out of warranty, expect €200-600 per handle including parts and labor.

A common concern across many EVs, including vehicles on the Geely SEA platform and the broader smart EV family. The always-on telematics modules, connectivity features, and background processes draw power from the 12V battery via the DC-DC converter. If the car sits for 2-3 weeks without being connected to a charger, the 12V battery can go flat, preventing the car from starting. The high-voltage battery remains charged but the car cannot access it without 12V power. Replacement of the 12V battery costs €150-250, with labor around €50-100. Using a trickle charger during extended parking periods prevents this issue.

Multiple owners of Smart #1 and #5 models report that key fob batteries drain much faster than expected. Rather than lasting the typical 1-2 years, some fobs need new batteries every 3-6 months. This appears related to the proximity unlock system continuously polling. The fix is simply replacing the CR2032 battery more frequently. Smart has not acknowledged this as a defect. While inexpensive per occurrence, it is an annoyance.

The #5 uses a heat pump system for cabin heating and battery thermal management. On similarly configured EVs (Hyundai Ioniq 5, BMW iX3, VW ID.4), heat pump failures have been documented, typically appearing between 40,000-80,000 km. Symptoms include loss of heating or cooling, strange noises from the HVAC system, and significantly reduced range in cold weather. The high-voltage compressor is the most expensive component, with replacement costs of €1,500-3,500 including labor. Given the #5's newness, frequency data is not yet available, but this is a known risk area for EVs in this segment.

The DC-DC converter bridges the high-voltage battery system and the 12V auxiliary system. If it fails, the 12V battery cannot be charged from the main pack, eventually stranding the car. On the related Hyundai/Kia E-GMP platform, the ICCU (Integrated Charging Control Unit, which incorporates the DC-DC converter) was the subject of recalls affecting thousands of vehicles. While the SEA platform uses a different architecture, the function is the same and failures have been reported across various EV platforms. The component is covered under Smart's 8-year / 200,000 km high-voltage component warranty for the first owner.

Early owner reports indicate that the Smart #5's advanced driver assistance systems can be overly sensitive. Specific complaints include adaptive cruise control applying unexpected braking during overtaking maneuvers on highways, traffic sign recognition incorrectly reading signs from preceding vehicles or adjacent lanes, and forward collision warnings triggering without visible cause. These are typically addressable via OTA software updates and calibration, which Smart has been rolling out. Sensor recalibration at a dealer costs €100-300 if required outside of warranty.