True on the convertors. The item that may have been lost...but Richard addressed it somewhat...is that the solar panels will be charging the battery during the day, then at night...the battery bank will be switched over to the load to run it, the panels will NOT be running the load at all, just the charger for gel-cell type batteries. The main question is...given the panels can provide only 480mA MAX at full sunlight....whats the calculation to figure out ,how long it would take to recharge a battery. I know thats rather ambigious, because the question is how low are the cells? That will depend on the battery of course, the bigger the capacity the less they are discharged, but lets go back to saying we have a 15 A/hr battery....its drained to lets say a capacity of 12 A/hr after a period of time....given the 480mA current from the cells, can you assume that for a perfect world, it would take about 2 hours to recharge 1A/hr capacity BACK to the battery? "Alan B. Pearce" wrote: >Another thing to consider is that a boost converter >has a negative resistance input (pretty much). As you >decrease the input voltage, the current increases >as it works to output the same power. Not just a boost converter, but every switchmode converter/regulator. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --------------------------------- Get your own web address for just $1.99/1st yr. We'll help. Yahoo! Small Business. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist