OnePlus has gifted us an amazing phone, but I was not convinced that the 4000 mAh battery could last the entire day on straight use. I wanted to see how long the device will hold up to constant use and how long can the screen remain on before the battery shuts off. It has been proven you never want to run your phone dry this will effectively cause the lithium ion battery to degrade faster and hold less of a charge.
Just a little background if you did not know Lithium-Ion (Li-ion) batteries are not like their predecessor the Nickel-Metal-Hydride. These old-style battery's developed memory over time. Meaning charge it half way, use it, then charge it again. It will not be able to fully charge again. Luckily the Li-ion never have this issue, but they are still battery's and there is a right and wrong way to keep them optimally charged and happy.
Per https://batteryuniversity.com state that there is a "sweet zone" to keep the longevity of battery going. Small partial charges are better than a full drain and charge on a battery wear and tear. But trickle charges used too often can cause more harm to the battery's and should not be used all the time. Keeping the battery charged between 60 and 75 percent is optimal but its okay to run between 25 and 75 percent. Try not to keep your phone plugged in while at 100 percent as it may try to continue to discharge/charge constantly which in turn will degrade the battery's performance over time.
NEVER charge your phone while using intensive applications liking watching movies or playing graphic intensive games as this will cause mini-cycles/parasitic load to occur. "A parasitic load confuses the charger by depressing the battery voltage and preventing the current in the saturation stage to drop low enough by drawing a leakage current. A battery may be fully charged, but the prevailing conditions will prompt a continued charge, causing stress." Extreme cold and high heat can also reduce optimal charging. Best way to charge your phone is when the phone is turned off. This way the charger can regulate the voltage necessary to charge your device properly.
Now on to the good stuff how did my phone handle the day. To test this, I did not just want to have the screen on and nothing happening that will not work. I need to have something that is using screen time. I decided to watch TV the whole day from my phone and I do not mean messing with channels or changing streams. I mean turn on the phone and leave the channel playing for as long as the phone can handle it. What I used is HDHomeRun to stream live over-the-air TV to my phone. My current settings were as followed: no battery saver, brightness was set to 65%, WiFi, Data, GPS, Bluetooth, NFC are all on.
I used AccuBattery application to help track my battery's usage over the course of 7 days before beginning this test. I wanted to see what the application states through its algorithms how long it believed my battery would last. Per its assumptions it states that my phone would be able to last 8 hours and 51 minutes with the screen on and 43 hours and 55 minutes with the screen off. I began the test, starting at 07:00AM and phone died at 03:24PM. The screen on time was recorded at 7 hours and 48 minutes with a discharge occurring around 12.4%/hr.
Though my phone states it will last over 8 hours with screen on time I was only able to get closer to seven hours and thirty minutes. Still its close enough for my needs. With the combination of screen on and off I have been happily getting a good full days worth of use. Remember to not over charge and try to hit the sweet spot charge of about 60-75 percent and your battery will surpass the odds of failure and last longer.
Enjoy and remember never use your phone or tablet while driving, be safe and healthy.
Check out some of my other blogs on the OnePlus 7 Pro:
Disclaimer: The Product Ambassadors are Sprint employees from many different parts of the company that love technology. They volunteer to test out all sorts of Sprint devices and offer opinions freely to the Community. Each Product Ambassador shares their own opinions of these devices, therefore the information in this post does not necessarily reflect the opinions of Sprint. The PA's do not represent the company in an official way, and should not be expected to respond to Community members in an official capacity. #sprintemployee