Reply #34: yes

[bongbong]

You posted one of the reasons that you make the negative connection away from the battery. But the main one is that the current has to be delivered from the alternator, not the battery. Otherwise there is a small chance you can harm cables or overload the good battery.

The hydrogen gas thing is rare. Unless you are in a closed space, the absolute worst case would be a small flame for a fraction of a second. And an improbability you'd have to add to that is an even smaller chance of it somehow igniting gasoline vapors. Vapors that are very rare with a closed combustion system like fuel injection. If the car is ancient or beat up it might have a leaky carburetor and/or leaky fuel line and/or old oil on the engine (which is usually almost impossible to set on fire anyway).

But you have to give instructions on anything more technical than "To Turn On The TV, Press The On Button" in a very detailed fashion these days.