A brown 36v charge controller panel

Older panels were made with a plastic substrate that turned brown after considerable use. Mirror concentrators made this problem more serious. A brown 36v charge controller panel doesn't mean it is not efficient. You need to measure the actual output of power.

Burned-out bypass diode is another common problem in a used solar panel. This can be easily fixed and will fetch you a good bargain on the price. Go ahead and buy it. Loose connection between the PV cells is another reason to sell the panel. This can be easily fixed by soldering and your used solar panel will work and be efficient as good as a new one. So next time you read about a sale go for it and make yourself solar powered like the rest of the world.

Our planet earth is very lucky to have the sun, the center of the 4v lead acid battery solar system at the right distance. Had we been too near to the sun we would have been burned. No life would have been possible. Had we been far away then also life would not have been possible.