after using Instructables quite a while I finally decided to create my own first Instructables. I bet you also have 20 different solar system on 1.5V, 4V and co. All those have their own solar panels and you would like to control all of them via one. That was exactly my problem after 4 small panels got destroyed. This project is not very hard to make and doesn't require any special engineering skills.
1x Solar Panel 12V
1x 12V Lead battery (I used this: bit.ly/BatterySolar)
Step 1: Connect the Solar Panel and Battery
Find a good place for your solar panel (Sunny place) and place your panel there. If possible build a construction so the panel is not laying on the ground. Find a cold place for the battery and a good place for the controller. When connecting start by connecting the battery first and then the solar panel. The controller's standard values are set for 12v lead batteries so you don't have to change anything.
Step 2: Connect Your Small Lamps
Using the step-down and step-up converters connect the lamps (you have to cut the cable) to the solar system. First, check the output voltage using a multimeter to not destroy your lamps. You can set a timeframe in the controller (0h = only when there is no sun, 1-23h = so many hours after there is no sun, 24h = always). Also when the voltage is too low you cannot extend the low-voltage cable with normal cables as the in-cable-resistance is too high. In the next days, I will post a 3d-printed case for the converters.