Modern cars with start-stop systems have more sensitive electronics and often AGM or EFB batteries. Therefore, correct procedure is especially important.
Preparation
- Both vehicles must have the same onboard voltage (12V)
- Ignition off, key removed
- Turn off all consumers (lights, climate control, radio)
- Vehicles must not touch each other
- If available: Follow manufacturer instructions (manual!)
Correct connection sequence
- Red cable to jump-start terminal or positive (+) terminal of the dead battery
- Other end to jump-start terminal or positive (+) terminal of the donor battery
- Black cable to jump-start terminal or negative (-) terminal of the donor battery
- Other end to:
- designated grounding point in the engine bay (very important!)
- not to the negative terminal of the battery
Many modern vehicles have dedicated jump-start points – be sure to use them!
Starting
- Start the donor vehicle
- Let it run briefly (1–2 minutes)
- Start the vehicle with the dead battery
Disconnecting (reverse order)
- Remove ground cable from the vehicle with the dead battery
- Remove ground cable from the donor vehicle
- Remove positive cable from the donor vehicle
- Remove positive cable from the vehicle with the dead battery
Important special considerations for start-stop systems
- Pay attention to battery type (AGM/EFB)
- Avoid voltage spikes (follow correct connection sequence!)
- Control units can react sensitively
- After starting, the following may occur:
- Error messages may appear
- Start-stop may be temporarily deactivated
After starting
- Drive for at least 20–30 minutes
- Alternatively: charge the battery externally (better for AGM!)
Tip
In modern vehicles, it is often the case that:
- The battery is worn out (typical for start-stop systems)
- Battery management system is active
In many cases, a new battery must be programmed / registered