It’s been a common ‘knowledge’ that charging a smartphone battery up to only 80% could improve the battery lifecycle dramatically — this has something to do with the nature of a lithium-ion battery. But only a few of us managed to unplug the charger at the exact moment before it’s fully charged. This practice is also extremely improbable if you, let say, left your phone charging before fell asleep. Meet Chargie, a simple gadget that could extend your phone battery lifespan. It’s basically will cut off the power automatically once the ‘maximum limit’ has reached, so the phone won’t be…