Here's a circuit that turns 12V into 20V. If it does that, it would probably almost double your 6V output as well. When a 6V charging system is working right, the battery terminal voltage is actually about 7.5 volts.

http://electroschematics.com/648/555-voltage-doubler/

Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
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