I got my first FitBit device, a FitBit Ultra, I believe, way back on March 9, 2012. I had that device clipped to my belt for about year before it went missing. Shortly thereafter, in May 2013, I got a FitBit Flex, and I used that device for well over three years, until a few weeks ago, when I finally replaced it with a FitBit Charge 2. Over the course of 4-1/2 years, I’ve logged more than 16,600,000 steps on my FitBit devices, and have found the data that comes out of them to be very useful. Here are my initial thoughts on the FitBit Charge 2.
1. The wrist band is a big improvement.
If there was one thing that bugged me about the FitBit Flex, it was the flimsiness of the wristband. Over the course of 3-1/2 years, I think I had to replace that band four times because of cracks and wear. That was annoying, especially early on when bands were backordered.
The wristband to the FitBit Charge 2 is, compared to the Flex, a vast improvement. It is wider, more comfortable, and a buckle-band, much like a watch band.

2. The heart rate data is fascinating and terrifying.
The FitBit Charge 2 constantly monitors your heart rate, which is a piece of data that I didn’t have with the FitBit Flex. For someone who is trying to get back into good shape, this is a valuable piece of information. It is also a little terrifying. When I get stressed I can see it reflected in an increased heart rate. I can see that my resting heart rate (currently 70 BPM) is somewhat higher than what I’d like it to be. Still, it provides me with a target to aim for, and a way of tracking changes to the measurement over time.
3. The automatic exercise recognition works pretty well.
One of the features of the device is that it can automatically recognize when you are doing some form of exercise. If you are doing the activity for more than 15 minutes, by default, it attempts to figure out what you are doing, and adds it to your exercise log.
I take 30 minute walks a couple of times a day, and the Charge 2 never fails to recognize these as walks and records them in my exercise log. I have also started using the elliptical machine several times a week, and much to my delight, my Charge not only recorded these exercise sessions on my exercise log, but correctly identified them as “Elliptical.”
It is not perfect, however. One way that I calm down our two-month old when she is upset it by sitting on an exercise ball and gently bouncing her in my lap. She loves this and calms down almost at once. Recently, however, I noticed that with each gentle bounce I take on the ball, a step is added to my step count. And if I happen to bounce on the ball for more than 15 minutes, it is added as a “Walk” to my exercise log. This isn’t terrible—after all, I certainly get a good abs workout—but it also isn’t accurate.
4. The automatic sleep logging isn’t quite as good as the Flex.
With my FitBit Flex, my sleep was automatically logged each night, and I can’t think of a time when I had reason to disagree with that the log said. With the Charge 2, there have been some minor problems. Generally speaking, the sleeping logging is good. But occasionally, I’ll find that the device failed to log my sleep for the night, or started or stopped logging at times that seem strange for me. For instance, I go to sleep at 9:30 pm, and fall right asleep, but according to the log, I didn’t go to sleep until 11:55 pm.
5. Battery life is good.
So far, the battery has lasted about 5 days per charge. It charges much more readily than my Flex ever did. I always had to fight with the Flex to get it to start charging. But the Charge 2 doesn’t have that problem. It goes from empty to a full charge in about 2 hours.
6. The alerts and alarms are helpful.
My FitBit Flex could use silent alarms to wake me up in the morning. My Charge 2 has the same capability. It adds, however, silent reminders to get up and move during the day. It also talks, via BlueTooth, to my iPhone. The caller names on incoming calls, and text messages will appear on the screen of my Charge. One nice feature is that the screen will turn on automatically when you turn your wrist to look at the screen. No pushing buttons or tapping of the screen necessary.
7. The device is water-resistant but not water proof.
One thing I really liked about the Flex is that it was waterproof1. You could take it into the shower, swim with it, etc. The Charge 2 is not waterproof, although it is water-resistant. Sweat doesn’t harm it, and getting it splashed apparently doesn’t harm it either, but showering and swimming with the device is not recommended.
8. Floor tracking!
When I went from the FitBit Ultra to the Flex I lost the ability of the device to count the number of floors I climbed each day. With the Charge 2, that ability was restored. It is not a huge deal, but it’s another nice data point to have.
9. I no longer need a watch.
Last Christmas, I got a simple watch because I felt like I was pulling out my phone to check the time, and then getting distracted by notifications. The default screen on the Charge 2 shows the time, date, and step count for the day, so I no longer really need the watch. I wore it with the Charge 2 for about the first week I had it, then gave it up.
Overall, I am happy with my FitBit Charge 2 so far. I think it is an improvement over the Flex, especially the band, and some of the bells and whistles that have been added to it are nice to have as well. Some of those bells and whistles aren’t really necessary for someone who just cares about step counts. But it was a worthwhile upgrade for someone like me, who dives into the data, and has been using that data in various ways for the last 4-1/2 years.
- Scott Edelman points out that the device was not, in fact, waterproof, but water-resistant. I’d swear that when it first came out, it was listed as waterproof. I’ve swam with my Flex and never had problem. Apparently, the Flex 2 is the first officially waterproof device. ↩