This budget DC-DC boost converter cranks up input voltage from as low as 2V to an output as high as 28VDC
A benefit to mobile electronics is the spill-over we get in the form of really cool modules to build our designs. In this case, we're talking about DC-DC Step-up boosters using the AeroSemi MT3608 IC. Attach it to your input voltage, and twiddle the trimpot until you get the output voltage you need (but it has to greater than the input). There's also step-down (with display), full-range (step up and down) DC-DC converters with different prices and size factors, but by limiting to one function, you save space and cost.
Dropping voltage is a relatively easy process, but creating a higher voltage out of a lower voltage almost seems like alchemy. The MT3608 uses a clever boost circuit with an inductor to turn a low input voltage into a usable higher output voltage. But as any good alchemist (or engineer) knows, there's always a cost involved: You may get more voltage, but the trade-off is a little-less than proportional output current. That means if you start with an input that has low voltage and a set current ability, you get high voltage and even lower current on the output. Keep this in mind, and you'll be fine!
To summarize, the positives are:
The negatives are: