A newly launched mobile phone runs off a single AA battery and can last for 15 years without being recharged.
The handset is known as the SpareOne and is designed for emergency use and as a spare handset only. Its designers also suggest it could be used for overseas travel with a local pre-paid SIM rather than pay expensive roaming charges. However, the handset is limited to particular frequencies depending on where it is bought, so for example European buyers won't be able to use the phone in North America.
The 15 year claim is a little misleading. Once in use, the phone will only work for around 10 hours of talk time before the battery needs replacing. The 15 years refers to the time that the average battery lasts when not in use.
The handset works with any SIM (though will allow calls to emergency services without a SIM), but is extremely low-tech. Besides voice calls, it's only function is a very limited text message system. There's no screen (other than a batter power display) but users can send a message reading "please call me" to any of the 12 numbers stored in the quick dial memory. If anyone attempts to send a text to the handset, they'll get an automated reply saying it can't receive texts.
The phone will launch first in the US, costing the equivalent of around £30.
