Better Re is a startup that has already exceed its $50,000 Kickstarter goal for a project that’s on the greener side of things.

Better Re plans to repurpose the removable battery from your old smartphone into an external power source for your phone, tablet and even your laptop.

They say that at the average rate we typically replace our smartphones every two years and their batteries still are about 80 percent efficient.

That’s quite a bit of wasted and unharnessed power that could serve a purpose instead of us mining for more lithium as demand increases. So, for $39 you can tap into that energy and use it to get extra time out of your gadgets.

The base tier includes the shell that turns your lithium-ion battery into an external power source and a USB cable, while $55 nets you the “full” package. That gets you the case, a USB cable, a used battery and engraved panels for the case.

Via EnGadget