The hidden 20Wh rule behind smartphone batteries: why iPhone and Galaxy still play it safe as China goes bigger
Chinese smartphone makers are increasing battery capacities beyond 5,000mAh, while Apple and Samsung remain near that mark, partly due to shipping rules for lithium batteries. U.S. regulations set a 20Wh limit per cell for streamlined transport, with stricter handling above that. Some Android brands use silicon-carbon anodes and 100W+ charging. Larger batteries can add weight and reduce space for other components.