New ‘Wi-fi battery’ never needs replacing

A new battery that charges wirelessly could revolutionise how devices are powered. The technology allows devices such as TV remote controls and smoke detectors to be recharged without you having to replace their batteries.

US company Ossia says its Cota Forever Battery, available in AA and AAA sizes, works in a similar way to how Wi-fi delivers data. First, a receiver in the device that needs charging sends a beacon signal to find the Cota transmitter, which is disguised as a tile in the ceiling. The transmitter then sends power back over the 2.4GHZ wavelength to the source of the beacon.

Ossia says this exchange happens about 100 times every second. The system knows which devices need power most urgently, and can prioritise accordingly.

Signals can bend around people and go through walls and objects, just like Wi-fi. They can be picked up from 10 feet away. This contrasts with current wireless-charging mats, which need to be in contact with devices.

The battery, which was unveiled at the CES 2018 technology show in January, could have benefits for the environment. Every year in the UK alone 600 million disposable batteries are thrown away. Only a third are recycled. Substances in batteries leak into the soil and groundwater in landfills, releasing pollutants and toxins into the air.

However, the battery will probably be tested in shops and companies before being sold to the public.