The charge times posted on our site are all real charging times. This means they are based on actual tests, but they are under ideal conditions (sunny, no cloud coverage, angled towards the sun).
However, if you are experience a cloudy or hazy day - this will decrease your solar potential and increase your charge rate. Similarly, any shading or dirt on the panel will do the same.
For best performance, be sure to:
Place the panels outside - you will get half the power and often some shading when charging through a window (not recommended)
Point panels directly at sun - once the panels get past about 45 degrees, power production drops steeply
Minimize shading and make sure nothing is covering any part of any cell
If it is cloudy, extremely hot or you have obstacles shading the panel, expect charge times to increase, sometimes quite dramatically. You can decrease charge times by increasing the size of your panel or adding a second panel.
Contact Voltaic Tech Support