Security researchers claim in a new study that the battery of a smartphone or laptop could be used to compromise a user's privacy. They have revealed that a lesser known feature of the HTML5 specification allows websites to find how much battery power a visitor has left on their laptop or smartphone, which can be used to track browsers online, according to The Guardian.

The feature, called the Battery Status API, is currently supported in the Firefox, Opera and Chrome browsers and was introduced by the World Wide Web Consortium (W3C) in 2012 with the goal of helping websites conserve user's energy.

It allows websites to collect information about your battery's charge level, voltage and discharging time. In fact, the data is so precise that a website can essentially create a unique fingerprint for each device to track your surfing activity, according to Business Insider.

By combining all of this information, it even becomes possible for websites to determine if a specific user is surfing in privacy mode.

Websites use the battery data to switch between energy-saving or high-performing modes and all of this is done without the user's knowledge or consent.

"The API does not require user permission to read the battery information, any website or third-party scripts included on them, can use the API. The API also does not require browsers to notify users when the battery information is accessed. That allows website and third-party scripts to access the battery information transparently - without users' awareness," the paper states.

While alarming, this practice is still relatively harmless. However, as IndiaToday reports, hackers can make use the same software to identify a user and track them around the Internet.

While using VPN (virtual private network) or going incognito may seem like safer options to maintain privacy, the study notes that there's simply no way to get around the security problems in the battery software.