I forget the number, but there is some upper limit on the wattage for the empower plugs. My old Gateway, you had to take the battery out, wouldn't charge and run the laptop. Since my newer Dell had an even bigger brick, didn't even think about trying it.

After some digging, seems like 75 watts is the limit?? I know the 319 outlets would kick off if I left my battery in.

So, do your homework before buying - if you have a big laptop, it may be too much for the empower to deal with