Good laptop for coding

Hi all! I'm a developer and I'm using a PC specialist assembled gaming laptop for coding. Performance perfectly fits my needs, the only problem is that the battery is not so good.

I'm thinking to take a second laptop to use when I need to use it on battery for long time. Most of the time I develop mobile applications, so I often need to launch smartphones emulators, emulate servers locally and many other things that, all together, drain battery fast. I want to use this second laptop for "quiet" sessions, with code editor and not many other things, leaving the heavy load for my gaming laptop.

So, the question is: in your opinion, at today, which is a good laptop with very good battery duration and good performance on medium load?

Thanks!