An engineer has built a giant rechargeable battery for his home using cells stripped from discarded vapes. Chris Doel, 26, recovered 500 lithium batteries and combined them into a 2.5 kWh pack that ...

A man has built a rechargeable battery pack big enough to power his whole home - using the batteries from discarded vapes. Electronics engineer Chris Doel, 26, stripped the lithium batteries from 500 ...

When it comes to hard problems, computer scientists seem to be stuck. Consider, for example, the notorious problem of finding the shortest round-trip route that passes through every city on a map ...