This is continuing the design of the previous stereo with some major design changes. The differences between this model and the last are that this one has a larger (3.4W) solar panel that is on a hinge to better capture the sunlight. Due to size constraints, I decided to take out the phone charger for this model. Using the 6600mA lithium ion battery, you will maximize your music playing times. This stereo LOVES to jam out in the sun but is also happy just chillin on your desk. Enjoy!!!