Fossibot F102 Review - excellent battery life, good performance, fast display

Battery Tests

Fossibot F102 packs a 16500 mAh Li-Pol battery with 33W fast charging support. All battery tests we run on the devices we review are developed by us and performed with the screen of the device being calibrated to 200 cd/m². Battery-saving features are disabled. The battery of our review unit was charged in full for 3 hours and 52 minutes with the provided USB cable and charger. The charging process develops steadily for the first 2 hours and 20 minutes after which the battery regains 80% of its charge. After that, charging slows down and the last 10% needs 1 hour and 32 minutes to charge. The battery temperature starts at 35°C and after 1 hour and 45 minutes reaches 45°C. It remains at this level for 20 minutes and after that gradually decreases to reach 30°C in the end. During our intensive browsing test, the battery of our review unit lasted for 43 hours and 42 minutes. This is an impressive result for this smartphone - the fourth best among all smartphones we've tested and it's in the company with devices with larger batteries or smaller displays and weaker chipsets. The discharging process develops steadily with a slightly slow start (first 2%) and a slightly quicker end (last 3%). The battery temperature starts at 28°C, reaches 35°C in 7 hours and a half, drops to 32°C in 15 hours, goes up to 35°C after 11 hours and drops again to measure 33°C in the end. With the display's refresh rate set at 120Hz, the battery of our review unit lasted for 33 hours and 28 minutes. The discharging process draws the same curve as the one drawn during the test at 60Hz. The battery temperature starts at 30°C, reaches 36°C in 40 minutes, and fluctuates around this level until the end going up or down a degree. The video test for battery life uses a 1080p video at 30 fps with a ~20Mbps rate. Our review unit's score is 47 hours and 21 minutes. That's the fourth-best result after the ones of the Oukitel WP15 with a 15600 mAh battery - 63:04 h, Oukitel WP19 with a 21000 mAh battery - 61:18 h, and Unihertz Tank with a 22000 mAh battery - 55:42 h. Having in mind that the Fossibot F102 has a larger display with an FHD+ resolution we can assume that it could easily be in the top place if it had a smaller HD+ display, like the Oukitel WP15, or a larger battery, like the Oukitel WP19. The discharging process is slow for the first two minutes. Then it maintains a faster and steady discharging speed. Five minutes before the end, the process slows down again. The battery temperature is stable from the start until the end fluctuating 6-9 hours between 30°C and 32°C. The 4K video battery life test uses a 2160p video at 30 fps with a ~55 Mbps rate. In this test, the battery of Fossibot F102 lasted for 38 hours and 42 minutes - the third-best result among all devices we've tested. The discharging process follows the one of the previous tests. The battery temperature curve is very similar to the one from the browsing test. It starts at the 30°C, goes up to 35°C in 6 hours, drops to 33°C in 12 hours, and goes up again to 36°C after 12 hours, remaining at this level until the end. For the 3D Graphics/Gaming test, the YEBIS OpenGL ES 3.0 3D Tech Demo is used. The result from this test is 24 hours and 39 minutes. Yet another impressive battery life result. The F102 takes the fourth place. The discharging process is relatively steady from the start until the end with a slightly slower start and a slightly quicker end - like the other tests. The battery temperature starts at 30°C, reaches 40°C in 2 hours and remains at this level fluctuating a degree up or down until the end. The above photos of the Fossibot F102 are taken with a FLIR thermal camera. They clearly show the smartphone is not very hot. The left photo shows the device's temperature during charging. The hottest part is the connector of the charging cable with a temperature of 39.6°C. On the device, the hottest part is slightly to the right of the center of the upper half of the body with a temperature of 38.3°C. The second photo depicts the device's temperature during our 3D battery life test. In this case, the hottest part is the center of the chin with a temperature of 42.1°C. The second hottest area is the same point that's to the right of the upper half's center with a temperature of 41°C.

Battery Settings

The Battery menu is very simplified. Fossibot has stripped off the battery manager and the battery usage data leaving the battery percentage toggle and the battery saver one. The toggle for the battery saver appears only if the smartphone is not plugged in. You can set a schedule for the toggle to turn on automatically at a certain battery percentage level. There's also a toggle for this feature to turn off automatically once the battery reaches 90%.