The huge variety of mobile devices on the market today are united by a single dependency: the battery. Every device depends on a battery to function; and it must be small enough to fit inside ever-tinier builds and efficient enough to last for hours. But this combination of size and efficiency can prove elusive. So perhaps it is no surprise that rather than hitch its wagon to a third party manufacturer, Google is trying to build a battery of its own.

According to a report in the Wall street Journal, the famed Google X research lab has been exploring battery technologies that Google might develop itself since 2012. Led by former Apple Inc. battery expert Dr. Ramesh Bhardwaj, the small research group reportedly includes just four people.

Although small in number, the group’s research could have an enormous impact on Google’s fortunes. The search engine giant has teams working on at least at least 20 battery-dependent projects, the Journal reports, from self-driving cars, to Google Glass, to an effort to use nanoparticles to diagnose diseases.

While battery technology has failed to make the same leaps in efficiency as superconductors in the past decade, new discoveries look promising. Researchers are hoping that new “solid-state” batteries will prove thinner, bendable, wearable. and even implantable in the human body. Thin-film, solid-state batteries transmit current across a solid, instead of a liquid, as in current batteries, which makes them smaller and safer.

The hope is that these batteries can be manufactured in thin, flexible layers ideal for smartphones and other mobile devices. But at this point they still cannot be produced cheaply enough for use in the consumer devices.

But if anyone can figure out how to get solid state batteries to consumers, it’s Google.