Galaxy S9 battery life isn’t as good as we had hoped
I had high hopes for the Galaxy S9’s and Galaxy S9 Plus’ battery life when Samsung announced the two phones in late February.
Despite the fact that the Galaxy S9 and S9 Plus have the same battery capacities as last year’s Galaxy S8 and S8 Plus — that’s 3,000mAh and 3,500mAh respectively — I expected them to exceed 2017’s phones in battery life. Or at least unquestionably meet the same standard.
The main reason for that expectation is the Qualcomm Snapdragon 845 processor that lives inside the Galaxy S9 and S9 Plus phones in the US and other countries. Samsung equips the Galaxy phones in some regions with its house-made Exynos chip, but it’s the Snapdragon 845 we tested most.
Qualcomm promised that its Snapdragon 845 chipset would deliver 30 percent greater power efficiency than 2017’s Snapdragon 835 chipset, which drove the Galaxy S8 and S8 Plus. Those stated battery savings imply that the Galaxy S9 and larger S9 Plus would run longer on a single charge than those two S8 phones, which use the Snapdragon 835 chip.
Instead, the Galaxy S9’s battery cut out sooner than the Galaxy S8 phones in our looping video battery drain test. The Galaxy S9 Plus fared better, outlasting the Galaxy S8 Plus in our battery tests, but only by a 4 percent margin. And even that gain is far smaller than the optimal battery savings suggested by the Snapdragon 845 chip. (See details below.)
Granted, ouris a very specific indicator of performance; it doesn’t paint the full picture of phone use, like loading up websites and downloading images, streaming videos and navigating in Google Maps. And it doesn’t guard against phone makers that “optimize” their software for precisely this kind of assessment. But our test does provide a baseline that’s useful for comparison, one that goes beyond casual observation.
On the other hand, pure observation showed that both Galaxy S9 and S9 Plus phones drained much slower than the Galaxy S8 and Galaxy S8 Plus when I wasn’t actively using them (that’s good). Again, I break all of this down below, so stick with me.
I’ve kept an eye on battery drain since I began using the Galaxy S9 Plus almost exclusively this March. And while the phone will last me from morning to night on a single charge, I’m disappointed that either the Galaxy S9 Plus isn’t taking advantage of the Snapdragon 845’s promised battery boost, or the chip is perhaps only theoretically more efficient.
The party to “blame” is hard to parse out since software and hardware work together to manage the phone’s battery resources.
Now, read on for lab test results, idle drain comparisons and what you can do to manage a Galaxy S9 phone’s battery life.
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