Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Have you been waiting for PV panels prices to drop?

smokeyj · 12-20-2009, 02:05 PM

The FET will most likely be controlled to act not as a switch ie ON or OFF but as a variable resistor.

Its job is to absorb the excess power put out by the panel. So if the battery for its charging needs requires only 5W of power and the panel is putting out 14W the extra W will be absorbed by this FET and dissipated as heat.

This 60V panel is really intended to charge a 48V battery. In this case the panel and the load are well matched. This panel will only be able to put about 1.2A into a 12V battery which is about 14W of charge power.

If you read the panel spec it claims an short circuit current of 1.2A. No way no how will it put out 5A.

12-20-2009, 02:05 PM	#46 (permalink)
smokeyj EcoModding Lurker Join Date: Dec 2009 Location: san fran Posts: 48 Thanks: 0 Thanked 2 Times in 2 Posts	The FET will most likely be controlled to act not as a switch ie ON or OFF but as a variable resistor. Its job is to absorb the excess power put out by the panel. So if the battery for its charging needs requires only 5W of power and the panel is putting out 14W the extra W will be absorbed by this FET and dissipated as heat. This 60V panel is really intended to charge a 48V battery. In this case the panel and the load are well matched. This panel will only be able to put about 1.2A into a 12V battery which is about 14W of charge power. If you read the panel spec it claims an short circuit current of 1.2A. No way no how will it put out 5A.