Not a strong battery life
I first want to mention that this device is very small.  It can fit in your hand.  It's not necessarily a bad thing because it packed a good punch for being so small.  In fact, the sounds seemed to be very good quality and the melodies that played were very soothing and calming.  All of my kids really enjoyed them.  Here are the problems with this device:<br />1. You have to charge the unit to 100% once it dies and CANNOT use it while it is plugged in.  So you use it until it dies and then it needs to charge to 100%.  It doesn't take too long to charge.  Maybe 3 hours or so.  I tried unplugging it before it had charged to 100% and it didn't want to work.<br /><br />2. There is no indicator of the battery life on the device.  You don't really know when it is dying or almost done charging.  So you can either choose to charge it every day before you use it or take a chance and use it until it dies.  At first it lasted us almost 5 full nights (around 50 hours of use in total).  We use it as a sound machine at night for our kids.  After a month of use, it started holding less and less of a charge.  We finally returned it after about 5 weeks because it wouldn't even last 2 full nights (or 20 hours).<br /><br />3. The "night light" isn't really a night light.  So the light on the device can either be set to "on" (which is VERY bright), "off", or "blinking" which is just simply distracting.<br /><br />If all of these things were resolved I would purchase several more because this machine was really convenient and the sounds were of good quality and not annoying or scratchy.<br /><br />*** A few things to note, we never used the night light so that was not the reason for our battery usage.  Also, I did notice that the melodies used up more battery life than the simple sounds did so if you are wanting to use it for a business with the melodies you will not be able to use it for more than 8 hours or so before needing to charge it again.
Rating: 2 stars