I use Unreal Engine a fair bit on a laptop and those times were a plug isn’t available… ouch. The default setup of UE4 assumes you are running on a desktop and runs as fast as possible. This isn’t exactly wonderful for battery life. By tweaking these settings I was able to get about 3x more battery life. Of course this is all at the cost of performance, but quite often you simply don’t need performance.
So if you like me work on a laptop and want to improve battery life, hopefully this will be useful to you.