On my recent trip to Europe, I forgot to bring the charger for my OnePlus Watch 2. I had planned to put the watch through its paces during the trip, but this oversight meant I would have to rely on the watch’s battery life to last the entire journey. The watch was set to last from Friday through Thursday, well beyond the promised 100-hour battery life. This was the perfect opportunity to test how long the battery could actually last.
The torture test began on Friday, February 23, at 8 am ET, with a long travel day ahead of me. The OnePlus Watch 2 was tasked with tracking my steps and heart rate while delivering numerous notifications during a 7-hour layover before my flight. It was during this layover that I realized I had forgotten the charger back at home. The pressure was on for the battery to last.
By boarding time for my flight to Barcelona, the battery had reached 88%. Not bad, but there was still a long way to go. I was using OnePlus’ default “Smart Mode” with the always-on display turned off. Throughout the flight, the OnePlus Watch 2 was never connected to Wi-Fi. I only checked my heart rate a couple of times during the 6-hour flight. Surprisingly, I got off the flight with just over 50% battery left, which was not a great sign.
On Saturday, February 24, the Watch 2 continued to deliver notifications and had more energy than I did by the end of the day. By Sunday morning, it was at roughly 25% and had not tracked my sleep the night before. By mid-day, the battery had hit 20% and the watch prompted me to turn on Power Saver mode. This still promised two days of use and opened up an entirely different way to use the watch.
The Power Saver mode on the OnePlus Watch 2 turns off Wear OS and operates entirely on RTOS. This mode still allows the watch to track health data, deliver notifications, and show a color watch face, all while conserving power. However, there are downsides, such as losing all Wear OS apps and the inability to reply to notifications. The experience is remarkably similar to Wear OS, but the details are different.
The last 20% of battery life lasted through the rest of Sunday and the day on Monday, all without any real battery anxiety. I would miss features like Wallet or Maps directions, but the fact that I could squeeze so much functionality out of that last 20% was impressive. On Monday night, I borrowed a charger from someone at a tech trade show to top off the battery. The watch had 13% battery left after roughly 24 hours on Power Saver mode. This means I could have made it through another full day, if not close to two, on RTOS.
Ultimately, the OnePlus Watch 2 lasted about 83 hours before I finally charged it up, with a little less than half of that time in the limited RTOS mode. The watch’s endurance is impressive, but it is also not immune to Wear OS issues as evidenced by the unexpected 30% drop on my flight. However, I’m not sure this situation could have worked at all with any other capable smartwatch.
The dual-OS strategy of the OnePlus Watch 2 meant that I had a fully functional Wear OS watch for a couple of days and a still-useful smartwatch for quite a while longer. The OnePlus Watch 2 is launching for $299. Stay tuned for our full review, coming soon.
