Over the years I've always read and been told that you want the booster car running for maximum boost. Made sense in the carburator/pre-computer era.

But does it make sense now? Seems to me the most important thing is avoiding any voltage spike that can damage either car's computer.

To avoid this, wouldn't the better approach be NOT to have the booster car running? If it has a strong battery, and is warmed up, it can sacrifice enough precious electrical essence to boost the other car, and still restart itself afterwards.

And with the donor car ignition OFF, there is no chance of a power surge in its system when the boosted car starts. Meanwhile, the boosted car sees only an additional 12v battery in parallel--connecting the final booster cable would be no different than reconnecting the native battery in the boosted car.

So it's better for both cars this way, yes?

Thanks for any help you can provide.

Doug Harvey