This is the second damn time this has happened to me. Last week I jump started my girlfriend's car (battery went bad). It took about 20 minutes to get her car finally started. Sure enough today halfway to work my battery light is on under 4000 rpms. Same damn thing happened in January when I jump started someone and I had to get a new alternator.

Is there something I'm doing wrong when jumping these people's car? Pos to Pos, Neg to Neg. Some say to put one of the negatives on the block, but I've never had success with that; it's usually not enough juice to start the car.

Any idea why this is happening? It always seems like I get screwed in the long run when trying to help people. I hope this damn alternator is still under warranty; I don't feel like shelling out $150 again .