[Cruzer4326]

In the case that youb drain your car's battery and use a jump pack, you are leaving the alternator to charge a dead battery. This is a bad idea! Alternators are battery maintainers and you wil run the risk of overheating, and thus 'burning up' the alternator. I'm with the Use Another Energy Source group.

 

[Blasirl]

Just for grins - don't forget to calculate voltage drop across any extension cord you use if you go that route.

Shorter cord and thicker copper - i.e lower gauge, is better. !2v DC is better than inverted AC voltage also.

 

[Barry Allen]

In the case that youb drain your car's battery and use a jump pack, you are leaving the alternator to charge a dead battery. This is a bad idea! Alternators are battery maintainers and you wil run the risk of overheating, and thus 'burning up' the alternator.

As long as you are actually driving somewhere at speed and not just idling the engine to charge the battery, it's fine. The airflow through the engine compartment and through the alternator cools it sufficiently.