> Anyone know of a pre-packaged system using solar sells that can power a modest PIC based system, while also recharging =A0batteries so the unit can work during the night. /> Joshua - please use only one tag (see FAQ). I'd have used [EE] but as Joe chose [PIC] I'll use that. You need to specifiy minimum required voltage, maximum expected average load current over a day and give some idea of how you will be locating the panel - out in the sun or under an eave makes a lot of difference. Also an indication of required lifetime of panel would help. Most epoxy covered PV pathlight panels will last a year or two if lucky. The more recent PET encapsulated ones should last longer depending on other factors. Output depends on active PV material area, type of PV material and more. Best is crystalline silicon - the ones witjh visibly separate cells which are soldered together with a metallic strip. You can use cells from say 3 x pathlight units that use one cell each to charge 3 cells. The inverters in such units are usually very inefficient and better avoided except for occasional use. Measuring actual active PV material area you can expect the following resul= ts. Note that many panels have dead space-or much dead space between cells. This is not always visually obvious at a glance. Full sun panel at optimum orientation to sun. 5 to 10 mW per cm^2 30 to 60 mW per inch ^2 Maybe 15/90 mW for the very very best material and construction - which you are unlikely to get. A bright but less than sunny day may give you 10% of the above. Inside / artificial lighting output will be close to zero. Expect an average of 4 to 5 hours per day average full sun equivalent. See www.gaisma.com for various areas. SO in bright sun the average power you can support continually is about 15% of full power or say 0.75 to 1.5 mW/cm^2 or 5 to 10 mW per in^2 of 24 hour operating power IF the panel is optimally oriented to the sun during daylight hours on a sunny day. Wet / overcast / cloudy / worse - expect less to much less to none. Encouraged ? :-) =A0=A0 =A0 =A0 =A0 Russell --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .