I just got 1 a week ago. Battery was at 79%, the next day it was at 100%. I maxed out my settings it would drop a little at night but back to 100 by mid morning. I wanted to see how it would do on my heavily shaded side of house before I buy another and right now, with very very limited sun exposure, its increasing by 1% each day. So I'm getting another and extension cords to get better access to direct sunlight. My experience is only a little over 1 week but I'm sold.