Does Bluetooth drain battery? How the NHS test and trace app could affect your phone - and if it’s secure

With the launch of the new NHS test and trace app in England and Wales today (24 September), the hope is that enough people will download and use it to make keeping the virus under control much easier

The NHS Track and Trace app launches in England and Wales today (Photo by Dan Kitwood/Getty Images)
The NHS Track and Trace app launches in England and Wales today (Photo by Dan Kitwood/Getty Images)

Speaking to Sky’s Kay Burley, Health Secretary Matt Hancock said, “Every single person who downloads the app is helping to improve how it can keep us safe.”

Once installed on a user’s phone, the app will remain running constantly in the background, utilising Bluetooth technology to communicate with other devices which also have the app installed. Using this information, the app will alert people if they have been in close proximity to another user who has already or later tests positive for coronavirus.

This comes after the launch of a similar test and trace app in Northern Ireland in August and then in Scotland earlier this month.

When the original version of the app now being rolled out in England and Wales was tested in the Isle of Wight and Newham, in London, it ran into several issues. These included people receiving false alerts, incompatibility issues with some older phones, and major issues with battery life.

Will the app drain your battery life?

Prior to its release, the impact on battery life was considered to be one of the potential limitations of the test and trace app. A survey by YouGov back in May found that 27 per cent of UK residents would be unlikely to use the app if it put even a small drain on their battery, rising to 46 per cent if its impact is moderate, and 67 per cent if it drains a large amount.

The app uses Bluetooth Low Energy (BLE) to monitor your proximity to others. The use of BLE should mean that the impact of using the app on your phone battery will be fairly minimal.

If you think your battery is draining faster than usual once you start using the app, most phones allow you to check the amount of battery being used by individual applications on your phone, within the settings.

According to NHS guidance, if the app is using more than five per cent of your battery life, you should report a technical problem, detailing the percentage of battery being used, the make and model of your phone and the operating system.

What about privacy issues?

Another concern that some have raised over the app relates to security and privacy. However, the app will collect hardly any personal information from users, as you don’t need to create an account to use it, meaning you won’t have to supply an email, telephone or home address, though it will ask users for a postcode when they first open the app.

According to a document put out by the NHS relating to privacy, ”The app has been designed to use as little personal data and information as possible.

“All the data that could directly identify you is held on your phone and not shared anywhere else.”

How to download the app

To download the app for use in England and Wales go to the relevant app store for your device, either the App store for Apple users or Google Play for Android users, and search for ‘NHS Covid-19 app’.

The apps for use in Scotland and Northern Ireland can be found in the same app stores, by searching for ‘Protect Scotland’ and ‘StopCOVID NI’ respectively.