There are 2 open questions here.
1. Is it a good practice to run a laptop directly from a 12 volt outlet? A secondary question - Are all laptops designed to regulate a 12 to 14V input to their desired voltage?
I for one, would't want to risk it without having a backup.
2. Is it a good practice to remove the battery while the power supply is plugged in?
I just tried it with my $150 ST5111. No problems, But I don't want to experiment
with my more expensive Dell. One benefit I noticed was there was heat escaping from the battery compartment, meaning the fan will come on less often, saving energy. On the other hand I think it's a little less water
It should be noted that, with a good battery in place, the higher current
draw will lessen as the battery becomes charged. A bad battery might require higher current
continuously. I'm guessing that it takes 100-200ma to trickle charge a laptop battery. Anybody know for sure?