I was jumping my friend's car today in a place with no cell phone reception.
He argued that the jumper cables should be attached after starting the donor car's engine. He said that it would decrease the risk of inadvertently depleting the donor car's battery. I thought this argument made sense.
We did so, and jumping the car was ultimately a success.
I came home tonight, and read that the jumper cables should have been attached first, before starting the donor car.
I am wondering: is there any risk of a donor car's battery being drained before starting the engine?