Moixa Energy has detailed plans to extend its USB-chargeable power cells to include battery packs for phone handsets and other portable equipment.

The UK-based firm already sells USBCell, an AA-size battery that can be recharged by plugging into the USB port of a computer, removing the need for users to buy disposable batteries.

Later this year Moixa will ship its first packs designed to power a phone handset. Like the USBCell, these will feature a built-in USB connector to recharge from a PC.

Allowing mobile workers to recharge their phone from their laptop will avoid the need to carry separate chargers for both devices, the company said.

"No one should need to carry a bunch of cables with them for every mobile device they use," said Moixa director Simon Daniel. The handset can still be charged the normal way when at home or the office.

Battery life could become an issue once again as new handset models gain power-draining features such as Wi-Fi, GPS and HSDPA support, plus always-on email that requires the device to keep a live connection to the wireless network, Daniel said.

Phone batteries are typically unique to a specific brand or handset range, so Moixa is working with leading vendors to produce packs for new models. The first packs will ship September or October when the handsets are set to launch, Daniel said, but he declined to identify specific vendors.

Some handsets will ship with a Moixa battery as the main power pack, while other vendors plan to offer them as an optional accessory.