I use this device to limit voltage into a fan whose hub gets too hot at battery charging voltages. The output voltage stays the same no matter the input voltage.
http://www.amazon.com/DROK-Adjustable-Regulator-Experimental-Converter/dp/B00BYTEHQO/ref=sr_1_1?ie=UTF8&qid=1407222286&sr=8-1&keywords=DC-DC+Voltage+RegulatorI just found one of my T10 LED bulbs starts flickering at voltages under 11.5. I'm not taking my batteries that low, but this same distribution point feeds my laptop, which can take 90 watts and pulls down the voltage on the circuit, so it would be nice to have an adjustable boost converter too.
