Solar Cells with 3 Red LED's Here's a great start for a solar cell project. These assemblies for sun-powered garden lights consist of two glass photovoltaic cells mounted on a plastic bracket with a charging circuit, two rechargeable AA cells, and three red LEDs. Between the solar cells is a photoresistor to sense light and dark conditions. In daylight the solar cells charge the battery. When it gets dark, the LEDs light. Solar cell surface area is 3.78" x 1.98". Cells provide 2.6 Vdc @ 25mA in bright sunlight. The batteries that originally came with this unit did not work, so we include a 2 -AA battery holder with 2 AA 800mA NiMh batteries.