My SmartDiesel 450 starts in the first seconds of idle with only 500 revolutions and runs restless. After a few seconds one hears a switching noise, and the speed goes to normal. The problem occurs regardless of the temperature. Interestingly, the problem can be solved almost always when I activate the booster function of the charger. This increases the battery voltage to 15–17 volts, and the motor starts up 9 of 10 times normal without the switching noise. It feels as if the engine is slowed down by the starter, air compressor or the alternator – then the additional load dissolves and the engine runs lighter. The higher voltage seems to significantly improve the start and is repeated effectively. If it does not immediately go to idle speed, it does so after 1–2 seconds, instead of otherwise after 4 seconds of pulse. I exclude classic faults like cooling candles, because the problem occurs independently of the temperature. The engine has power => is healthy: It needs 1–2 seconds longer from 0–100 km/h than indicated and reaches GPS-measured about 134–135 km/h.