i TOTALLY AGREE. In fact we have designed a circuit that boost solar panel voltage using a boost circuit converting 10.5V to 15.5 volts and further using 317. automatic switching through 9015 and IRF . The use of ZD ensures the voltage to the battery is never above 13.5v. Further the use of a coil the battery output to the LED light it lights up a chain of 5 led’s in a series upto 10 . So 50 led giving 250 Lumens and consuming less than 2W.