Best answer: Battery life on the Core i5 model is substantially better than the last Surface Pro while also running cooler.
Microsoft: Surface Pro 6 (from $899)
Significant improvement on the previous model
During the course of our Surface Pro 6 review battery life was one of the key metrics we benchmarked. Using the PC Mark 8 Home Battery test, the Surface Pro 6 came away with a score of 5 hours and 25 minutes.
The Core i5 2017 model Surface Pro, by comparison, scored only 4 hours and 30 minutes. Not only is the Surface Pro 6 better, it's significantly better, with more than 20 percent longer life.
Don't be alarmed by the benchmark
It's easy to look at the figures above and be a little alarmed. But you shouldn't be. The PC Mark test is designed to leverage both the CPU and GPU, and so it will always come out lower than you'd expect to see in day to day life.
Indeed, more regular computing, such as web browsing, media consumption and work inside apps like Microsoft Office will yield a much stronger battery life. What can be taken away, though, is that you can expect at least one hour more from the Surface Pro 6 over the older model.
The Surface Pro 6 also runs cooler
It's not just longer battery life you get from the Surface Pro 6, either. Like its predecessor, the Core i5 Surface Pro 6 is fanless, but it's also packing two more cores with four more threads.
Despite being a quad-core processor, the Surface Pro 6 runs a little cooler than the older, dual-core Surface Pro. In our testing, the Surface Pro 6 was consistently 4 degrees Fahrenheit cooler than the previous model. It doesn't sound like much, but cooler is cooler. Especially when you're also getting more power.
Good battery life
More powerful and longer lasting.
Even though the Surface Pro 6 has a quad-core processor, the battery life is significantly better than the older model while also running cooler.