No light! because of a low voltage battery. How do you increase the voltage up? You can do many ways. And, I recommend a simple step-up converter circuit using TDA2822.
Simple DC to DC converter using 555 timer IC. You can build easily it.
This is simple the 12V to 24V step up converter circuit, can convert DCV from 12V to 24V at 1A max. Using TDA2004. Why is amplifier IC? It easy&inexpensive.