Your not going to get a very good battery life with just about any laptop especially ones for gaming.
The ones with good batteries are usually overpriced to begin with and computer with sub par hardware.
The best thing you could do if battery life is a must is to buy a laptop then purchase a separate battery that is much better but you have to make sure the battery is compatible with your laptop.
Acer is crappy all around. So you want to be a DJ? I guess the program you're using is FL studio XXL producer edition? A laptop with 3gig ram is enough for that one, so just get one with 4gig.
Here is what you'll need to search for in a laptop;
Ati mobility HD 5650 (or greater).
4gigs of ram.
interl i5 (or greater).
If it's mainly for online gaming a Toshiba Tecra S11-11F will be enough.
FL is everything in one to be honest. Search the laptop I posted. It's definitely enough to run those software, even a normal laptop with the price of 400dollar would be enough. I mostly based on the gaming part.