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You can’t tell how long a phone will last from its 8,340 mAh rating alone. To find out whether it lasts longer than another phone—or than it did before a change—compare elapsed use under the same workload, settings, and conditions. The capacity figure does not identify a specific handset, so an exact-device verdict requires the model and comparison phone.
What “lasts longer” should mean in your comparison
Choose the comparison before you start: two phones against each other, or one phone before and after a change. Record the exact model and regional variant for each handset. Then decide what counts as the endpoint, such as reaching 20% battery or shutting down. A comparison is meaningful only when both sides start and stop on the same basis.
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Capacity, measured in milliamp-hours (mAh), is not a runtime measurement. Actual results depend on the phone and its conditions of use, including display brightness and refresh rate, network and signal, background activity, battery age and health, temperature, and workload. Published testing methods control some of these variables precisely because they can change the result: PhoneArena’s battery test methodology and GSMArena’s methodology both describe factors that influence comparisons.
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For an everyday-use comparison, include the activities that account for your phone use—perhaps calls, browsing, streaming video, gaming, or navigation. Use the same apps, content, duration, and order on both devices. If you mainly want to know how long a phone can stream video, test video by itself and label the result as a video-use comparison rather than an all-day estimate.
#1 Best Overall
- Up to 3.5 Phone Charges On the Go: Compact and easy to carry, this 15,000mAh power bank keeps you powered for travel, commuting, and emergencies. Charges iPhone 17 up to 3.5 times, Samsung S26+ up to 2.5 times, and AirPods Pro up to 20 times.
- 40% Smaller, 45% Lighter: Designed for power without the extra bulk, this compact power bank is 40% smaller and 45% lighter than conventional models, making it easy to carry for travel and daily use. Built-in USB-A, Type-C, iOS, and Micro cables keep your devices ready to charge—no extra cables needed.
- Airline-Safe Power, Trusted Worldwide: Safe charging you can trust. Join over 50 million users worldwide who rely on our safety-focused design for worry-free charging and carry-on travel.
- 50% Power in 30 Minutes: Get fast, convenient charging when you need it most. This 22.5W portable charger powers your phone up to 50% in just 30 minutes, ideal for busy days and travel.
- Charge 6 Devices at Once: With 6 outputs and a bi-directional Type-C port, this portable charger powers multiple devices at the same time. Compact enough for your pocket or bag.
GSMArena’s Battery Life Test 2.0 uses calls, web browsing, YouTube video streaming, and a looping 3D game, then combines them into an estimated Active Use Score. Its announcement describes a balanced mix that gives slightly more weight to web and video, and says readers can adjust the assumed use mix. See GSMArena’s Test 2.0 announcement.
Run a repeatable phone-to-phone comparison
- Set the starting conditions. Charge both phones fully and let them settle before the test. Keep temperature and background activity as similar as practical, and avoid installing updates or changing settings between paired runs.
- Match the display and connection. Fix brightness at the same level, use the same refresh-rate policy, and connect both phones to the same Wi-Fi network or cellular service in the same location. Record any unavoidable differences, such as a weak signal.
- Run the same schedule. Follow your chosen sequence of calls, browsing, video, and other relevant tasks with the same duration and content on each phone. For a single-activity test, keep that activity consistent throughout.
- Log the result. Start at the same charge level. At fixed intervals, note elapsed time, remaining battery percentage, and screen-on time. Stop both runs at the same defined point, such as 20% remaining.
- Repeat the comparison. Run the schedule more than once under comparable conditions. Report the range or median rather than relying on a single run, which can be affected by changing signal, temperature, or background activity.
A 20%-remaining endpoint compares partial discharge; it does not establish total runtime from full charge to empty. State the endpoint alongside the result. These steps are a practical way to control variables, not a claim that there is one universal testing standard.
Rank #2
- Ultra-Slim & Light weight Design: At just 0.63 inches thick and 8.11oz, this is the slim and light 10000mAh power bank. Perfect for travel, it easily fits in your pocket or bag without adding bulk.
- 22.5W USB-C Fast Charging: Equipped with USB-C input and output, this power bank supports PD3.0 and QC4+ fast charging, delivering up to 22.5W of power. Charge your iPhone to 65% in just 30 minutes or power up multiple devices quickly.
- 3 Output & Dual Input: Features 3 outputs (2 USB-A + 1 USB-C) and 1 inputs (USB-C ), allowing you to charge up to three devices simultaneously. Ideal for smartphones, tablets, earbuds, and more.
- Wide Compatibility: Works seamlessly with a wide range of devices,Compatible with iPhone 17/16/15/14/13/12, Samsung Galaxy, Google Pixel, iPads, AirPods, Android tablets, and other USB-C devices.
- Advanced Safety & LED Display: Built with an 8-Layer Protection System to prevent overcharging, overheating, and short circuits. The LED digital display shows the remaining battery percentage, so you’re never caught off guard by a low battery.
Keep a useful real-life battery log
If you want to assess your own routine rather than run a controlled comparison, keep a short log over several ordinary days. Record start and end charge, screen-on time, your broad activity mix, whether you used Wi-Fi or cellular data, and unusual conditions such as weak signal or extensive navigation. Compare similar days where possible: a navigation-heavy day and a mostly idle day are not equivalent tests. Treat this as a record of your use, not a laboratory result.
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Review the test method before comparing published figures. Brightness, network conditions, workload, and scoring methods differ, so results from separate outlets—or separate versions of one outlet’s test—may not be directly comparable.
Rank #3
- Universal 5V Battery Pack for Heated Clothing: Compatible with 5V heated jackets, vests, and trousers. This upgraded battery pack offers steady, reliable warmth, keeping you comfortable through any cold-weather activity.
- Pocket-Sized Portability: At only 5.5" x 2.6" x 0.5" and just 0.5 lbs, this slim, lightweight battery is built to go anywhere. Its compact design fits easily in your pocket, so you can stay powered and comfortable wherever the day takes you.
- High 10,000mAh Capacity: Reliably charge most smartphones 2-3 times or a tablet once, providing ample power for a full day out or during travel.
- Triple-Port Fast Charging: Two USB-A ports and one USB-C port allow you to charge up to three devices at the same time. Whether you're powering a phone, tablet, earbuds, or other small devices, you get fast, convenient charging without waiting for an available outlet.
- Comprehensive Safety System: Features advanced protection against over-charging, over-discharging, over-current, over-voltage, and short circuits for safe charging of all your connected devices.
| Publisher or tool | What the method measures | What to check before comparing |
|---|---|---|
| GSMArena Battery Life Test 2.0 | Calls over 4G/VoLTE, interactive web browsing, YouTube streaming, and a looping 3D game; combined into an adjustable Active Use Score estimate. | Use the Test 2.0 label and workload mix. GSMArena says it discontinued its former Endurance rating, so do not treat an older Endurance figure as the same score. Method announcement |
| GSMArena legacy battery tool | An Endurance estimate based on one hour each of calls, video, and web browsing per day, plus standby; sliders allow the modeled components to be changed. | This explains the older Endurance figure; it is not the newer Test 2.0 score. Legacy tool |
| PhoneArena | Separate scripted browsing, streamed-video, and gaming tests. | The methodology lists 200-nit brightness, Wi-Fi, 100% battery health, latest firmware at test time, and new devices in controlled labs. Compare specific use-case results where possible, and account for its warnings about signal, temperature, and aging. Results and methodology |
| Tom’s Guide | A scripted web-browsing test using the default browser at 150 nits; the guide says it tests default refresh settings and may also test alternate refresh rates. | Its 2026 guide says newer reviewed models were tested using an updated version. Check the specific phone’s test version before comparing. Methodology and 2026 guide |
These results are controlled comparisons, not personal guarantees. GSMArena and PhoneArena both warn that real-world results can differ with conditions. When weighing two published results, line up the exact model and regional variant, battery age or health, test version, workload, brightness and refresh rate, network conditions, and the runtime endpoint.
Put Tom’s Guide’s runtime figures in context
Tom’s Guide’s 2026 guide calls nearly 11 hours the average smartphone runtime in its web-browsing battery test. It says phones generally need to approach 16 hours on that test to make its longest-lasting-phones list. Those numbers describe that publication’s test and list threshold; they are not universal daily-use averages or predictions for an unidentified 8,340 mAh phone. Tom’s Guide’s guide and methodology provide the relevant context.
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