1khpumx¶

1 excerpts.

Reddit thread: Another Smart brought back to life.¶

reddit.com/r/SmartCar/comments/1khpumx · p. 1 · Applies to: 453

Source: r/SmartCar (score 127, 53 comments) Topic: Battery charging, BMS lockout, fuse failure Models discussed: 453 Solution status: yes

Problem: 2015 Smart ED battery had gone dead for at least a year, causing the battery's current sensor to be damaged and the BMS to lock out. Also discusses a 2017 Smart ED that stopped charging, with Mercedes diagnosing a need for full harness and charger replacement at $8k+.

Solution: For the 2015: slowly charge the battery with a power supply over several days, perform a load test, then reset the BMS (cost $900). For the 2017: discovered two hidden fuses in the charger's wiring harness, one had blown; replacing the fuse (approximately $8 in parts) resolved the charging issue in 3 hours.

Key facts: - Dead Smart ED batteries can sometimes be recovered through slow charging with a power supply over several days - When EV batteries go dead, the current sensor gets damaged and BMS locks out, requiring BMS reset ($900 in this case) - Hidden fuses in the charger wiring harness are a common failure point in Smart ED charging systems - Mercedes may over-diagnose and recommend full battery replacement when only a simple fuse replacement is needed - Both vehicles discussed were purchased cheaply specifically because they were non-functional, demonstrating viable DIY repair opportunity