I recently purchased a Schumacher SJ6 portable emergency charger. All of the instructions indicate that this thing is for jump starting the vehicle when the battery is dead. Is it possible to fully charge a battery with this thing? If so can I leave it plugged in while I do it? I hate the thought of straining the alternator.

Thanks

And if someone could explain to me why I shouldn't do this, if I shouldn't, that would be great

 

Don't sweat the small stuff.
......

 

No. it is designed to provide enough power to get the engine started so you can get someplace to charge your battery. The alternator is a maintenance device and wont completely charge your battery.

 

The alternator isn't like an A/C pump in that it doesn't have a clutch. If the pulley is turning, the internals are spinning. The coils become energised on demand, but that doesn't "wear anything out" in a mechanical sense. You're not straining anything.

 

Thanks for the replies, everyone.

I went out and got myself a small charger.