Very basic question about jump starting 2008 V70

[Discombobulated]

The link you posted says this:

‘If you are using a computer right now, you are using a piece of equipment that is sensitive to voltage spikes and surges. These voltage spikes and surges can even destroy your computer. What is a voltage spike? What's the difference between a spike and a surge? A voltage spike is a sudden increase in voltage that lasts for less than 3 nanoseconds. A sudden increase in voltage that lasts for 3 nanoseconds or more is called a voltage surge.’

I accept I have incorrectly called a voltage surge a voltage spike but nevertheless this is the reason for not having the engine running on the donor car when connecting jump leads to the casualty vehicle and the reason why having the headlights switched on helps, it softens the surge caused by the sudden difference in voltage.

[Dippydog]

I was always taught that the donor vehicles engine should be off when connecting the jump leads,then connect -ve last/disconnect first,so I've always done it this way and never yet turned lights/anything else on during the process and had no problems doing so.On many new cars you can't even get to the -ve battery terminal without dismantling the scuttle panel or other such bits and they have a dedicated earthing point on the bodywork to attach a jump lead to.

[apersson850]

There's no need to mess with the lights or anything. The impedance in the jump start cables and clamps is enough. As stated above, if the car's battery is below the level where the CEM will start (usually around 7 V), then you can't even start the lights.

The proper connection scheme is like this:

1. Red cable to dead car's battery plus.
2. Red cable to donor car's batttery plus.
3. Black cable to donor car's battery minus.
4. Black cable to dead car's engine block.

Remove in opposite order.
This avoids any sparks near any battery, and that's by far the greatest risk involved here.