Nokia has announced global rollout of a firmware update to its Lumia 800 smartphone to improve battery life.

The latest software for the smartphone is version 1600.2487.8107.12070 and is the third update in the space of four months. Nokia said it was originally scheduled for 18 April but had been brought forward.

However, Nokia warned: "The update will not span the globe all at once. It will be queued up over 4 weeks, beginning today (28 March) for the first batch. Subsequent phased updates will be on 4, 11 and 18 April"

Users can check whether the update is available on Nokia's website. At the time of writing O2, Orange and T-Mobile are 'waiting for approval'.
Without detailing exactly how, Nokia said the update with improve battery life and power management. Another part of the upgrade improves bass for better music and voice quality.

A big disappointment for Lumia 800 owners is that Wi-Fi tethering is still yet to be introduced due to prioritising the battery issue. Nokia said that the feature 'on its way' but can't specify when.

Last week, Nokia said that Windows Phone handsets have outsold those with Symbian in the UK this year.