These days, just about every Apple product is defined by a non-removable battery. It’s with no small hint of irony, then, that Apple just received a US patent for a universal removable battery system. As proposed, the technique would let Apple cut batteries from lithium-polymer or similar materials into commonly sized packs that could then be swapped between devices, providing all the benefits of removable, rechargeable batteries with a longer lifespan than an old set of AAs. Read the full story at Engadget.