Battery life is generally the slowest thing to test on a gadget, and it's almost always the toughest to get right. There's just no way to rush it, and there are just so many variables regarding how people use a particular gadget that it's always one of those "your mileage may vary" type of situations. Last week, some very early reviews of the Moto 360 smartwatch lambasted its weak battery performance. It's possible they may have jumped the gun.


Generally we feel that when reviewing a smartphone (or a smartwatch, in this case) a week is pretty much the minimum amount of time we should spend testing the battery. That is to say that this is not a review, nor is it a final, conclusive statement on the matter. A lot of our readers have been asking how the battery has been, and so here is my experience thus far.


Friday

My first full day with the Moto 360 started at 7:30AM. I had ambient mode switched to off—which is the default mode—so the screen would only wake up when I made the "look at my watch" gesture or tapped the screen. I got a ton of notifications that day, did some navigation, played with voice controls, and was frequently checking my heart rate (something the watch does constantly in the background anyhow). I went to sleep early that night at 10pm, but I still had 27 percent battery left when I did.

Saturday

Saturday wasn't much of a stress test. After pulling the watch off the charger at 10:30AM, I spent a good chunk of the day on an airplane from Chicago to San Francisco. My phone was off, so the watch wasn't getting notifications, but it was still humming away. As soon as I landed, I continued playing with it like crazy (new toy syndrome) as I had the day before. I had a very, very late night and ended up sleeping with it still attached to my wrist. When I woke up in the morning, there was still plenty of juice left. I didn't make it to the charger until 9am on Sunday morning (that's 22.5 hours if you're counting) but I still had 19 percent left in the tank.


Sunday

The Moto 360 charges fast: at 10AM, one hour later, the watch was fully juiced and ready for action. This time, I turned on ambient mode to check out the difference. In ambient mode, the screen dims but never completely turns off, making it easier to steal a glance at the time from any angle. It's worth noting that ambient mode is the default of the Samsung Gear Live and the LG G Watch, and both make it through a whole day in that mode and then some, usually. Battery life definitely takes a hit here with the Moto 360, which is a shame because I really prefer the ambient mode. When midnight rolled around I was down to 15 percent. Not terrific.


Conclusion

No conclusions yet. It's still too early. We will say that so far it's looking like the battery will go 24 hours plus if you leave ambient mode off, depending on how much you use features like voice commands. If you want to keep ambient mode on, well, it should still last you until the sun goes down. We think. This may also be affected by how bright it is where you are, since this is the first Android Wear watch with an ambient light sensor. The Moto 360 also appears to have the brighest screen of all the Android Wear watches so far, which might account for some of the difference.


I do think we can already say that no, battery life definitely isn't as good as it is on the other two Android Wear watches currently on the market. That said, this is the only Android Wear watch that's constantly monitoring your heart rate, giving you a much more insightful health metric than the others can deliver. Up to you if it's worth the tradeoff, because you can't turn off that heart rate sensor. The bare minimum we expect from a smartwatch is to last from dawn till bedtime—and it seems the 360 can do that—but what we really want is a watch that has zero chance of punishing you even if you use it heavily and occasionally forget to charge it.

We'll be doing plenty more testing leading up to our full review in the days to come and we hope to have a more solid answer for you then. So far these are the facts as we have observed them.