Many of us have switched to wireless headphones in recent years. They do away with tangle-prone wires, and can make things much simpler if your smartphone lacks a headphone jack. But, as with any cordless device, the rechargeable batteries don’t last forever, and they can be surprisingly hard to replace. Deteriorating battery life was a top reported fault in our latest headphone reliability survey. No one wants to be forced to upgrade their headphones just because the battery wears out, especially with many wireless headphones costing £100 or more. It’s not great for the environment either. And if you opt for a truly wireless earbud-style set, such as the Apple AirPods, you’ll typically only get around five hours or so of playback before needing a top-up from the charging case even when the headphones are brand new, so even a modest deterioration in battery life over time can be annoying.