How to estimate a laptop's battery life before purchase?

Solution 1:

Yes embedded graphics save power, especially if they are integrated on your processor! Compare processors and see how much power they consume. And i recommend buying SSD not standard HDD, resulting in 30+ minute battery boost!

Solution 2:

You can try to find reviews for your particular notebook model.

Usually you can find battery lifetime in technical specifications on official website of company who made this laptop.

If it says, for example, that battery longs for 4 hours, then it usually means, that under full load (gaming, compiling) it will last 70-80% of that time.