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Samsung Galaxy Note 9 battery review: Huge, but enough?
June 12, 2025
In most metrics, theSamsung Galaxy Note 9is an impressive flagship phone. It’s got agreat camera, it’s very powerful, and it’s one of the best Android phones on the market. Perhaps most importantly, it’s got one of the best batteries in the Android ecosystem.
Samsung Galaxy Note 9 specifications
Before we launch into how well the Samsung Galaxy Note 9 charges, remember this battery is powering one heck of a phone. A high-powered processor, integrated GPU, lots of RAM, and a bright screen all combine for some serious power draw. As far as components go, the Samsung Galaxy Note 9 —like the rest of the Note series before it— offers the most comprehensive constellation of parts out there.
It’s not surprising the battery inside needs to store a lot of juice. By providing charge to so many power-hungry components, the Galaxy Note 9 needs a lot more to stay competitive. At 4,000mAh, it’s a beast of a power cell. However, it’s not the only phone with that cell. TheHUAWEI P20 Proand theRazer Phoneboth have enormous batteries
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Even if it was a design necessity, Samsung packed a lot of power into that chassis. Though a couple competitors match the raw size of the battery, the Note 9 has a little bit of an edge — a little weird, given how packed to the gills it is with hardware.
So what does all that mean for daily use?
Samsung Galaxy Note 9 battery charging tests
A high capacity battery usually means charging your phone fast enough to be used for a decent amount of time is a challenge. You might be thrown a bit to see that the Note 9 is merely compatible with Quick Charge 2.0 when competing phones are already on Quick Charge 3 or 4. But in actuality, the unit uses Samsung’s proprietary management called Adaptive Charge — which can exceed USB’s power specifications if you use Samsung’s proprietary chargers. Consequently, the Note 9 can suck down juice and store it very quickly. In our tests, the Note 9 outpaced all other phones except the HUAWEI P20 Pro.
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That fast charging doesn’t help the Samsung Galaxy Note 9 charge to full faster than other phones, though. It still takes quite a while — though for some reason thePixel 2 XLstruggles more, possibly due to thecharge speed.
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It’s tough to knock the Note 9 for its charging, especially considering it’s much quicker than you’d expect. That extra waiting time translates into better battery life overall, especially with common tasks.
We were unable to test how fast thewireless charging unitperforms, but given the difference in charging rates, use it at work or charging overnight.
Rundown tests
The Samsung Galaxy Note 9 has more than enough to handle heavy daily use. Its battery rundown scores are excellent. The phone predictably handled tasks like video watching and Wi-Fi browsing quite well.
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The gigantic battery handled mixed tasks well too, and users can expect a great deal of screen-on time. If you fly a lot, the Note 9 seems like a logical choice to bring with you — especially if you need your phone to be both your in-flight entertainment and primary conduit to the world once you land.
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All our battery tests were performed with default settings, and at the same brightness level of 200cm/m2. If you adjust the brightness higher or lower, your results will obviously vary. Additionally, changing the default resolution from the FHD setting to the WQHD+ setting results in a fairly predictable around ~5 percent drop in battery life. While the added capacity of the battery can easily absorb that kind of hit, it defeats the purpose a little bit, right?
We recommend only switching to that mode if you really need to watch a movie with your eyes closer than 16 inches to the screen. Unless you have better than 20/20 vision, you’reunlikely to noticethe difference.
Among the Samsung lineup, the smaller S-series phones like theSamsung Galaxy S9 and S9 Pluswon’t keep a charge with high screen-on times as well, but they’re not bad. The Note 9 is just something special.
Conclusions
The Samsung Galaxy Note 9 has a stellar battery, and makes the most of its charge capacity. Because the phone has such a huge battery, it unsurprisingly has a similarly huge advantage in battery life over its closest peers too. Its main weakness — charge time — is head and shoulders above even some of the more popular mid-range phones out there.
There’s really no downside to the Note 9 as far as the battery is concerned.
Next:Samsung Galaxy Note 9 camera review
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