Is it possible for your laptop to use more electricity...?

Question

What uses more electricity:

When I charge and go on at the same time

Or

I put the laptop to sleep and charge it?

If it uses the same electricty, should I always charge and use at the same time then?

Answer 1

The battery is less than 100% efficient, so it saves energy to charge while using.  

But expect the charging to take longer, since the power adapter is charging the battery *and* operating the computer.  This may also mean more heat, which can shorten battery life.  

Answer 2

You have to be obsessed with energy usage to even ask that question (and if you can afford a laptop the difference is insignificant), I hope you don't go around unplugging everything from the wall to stop the standby power usage.

But either way, there's not likely to be much difference (though the battery will change faster if the computer isn't being used) unless not using it while it charges means you use it less.