Overview
- Connect in this order: red clamp to donor positive, red to recipient positive, black to donor negative, and black to a solid metal mass point on the recipient rather than its battery, as GTÜ warns that sparks at the battery can ignite explosive gases.
- Secure both vehicles before any cables are attached by parking on level ground, selecting Park or neutral, setting the parking brake, and keeping people clear of the gap between cars to prevent rollaway injuries.
- Start the donor first and the recipient a few minutes later, let both engines run for about three minutes, then remove the clamps in reverse order, with a high‑draw consumer such as the blower switched on to reduce voltage spikes; ADAC notes some cables include protection circuitry.
- Check the owner’s manuals before using a donor car because many manufacturers prohibit using electric or hybrid vehicles to supply power, and stop after several unsuccessful attempts to avoid damaging control units, TÜV Süd advises.
- Battery issues account for roughly 42% of breakdowns, and cold weather sharply cuts performance to about 65% at −10°C and 50% at −20°C, so experts recommend keeping the battery well charged, tested, and properly maintained.