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Software defined smart battery arrays extend laptop life

Mon 5 Oct 2015

Battery charging

Microsoft engineers are working on a new approach to extending the battery life of laptops, tablets and wearable devices, by monitoring user habits.

A new research paper, titled ‘Software Defined Batteries’ (SDB), outlines a study into a radical charging alternative which uses a smart battery system to keep consumer-grade gadgets going for much longer than the current norm.

Lead researcher Ranveer Chandra explains that waiting for the ‘perfect’ battery to be released would be nonsensical, suggesting that ‘no single battery type can deliver the ever-growing list of requirements of modern devices’ and demand for high capacity, fast charging, low cost, less volume, lighter weight, less heating, better longevity and high peak discharging rates.

Rather than perfecting single battery chemistry and relying on hardware – limiting factors in current mobile system design – the engineers decided to make use of existing technologies and placed multiple battery control under the duties of the operating system to create a software-defined approach. The proposed system combines groups of different batteries optimised for various scenarios, offering features such as ‘fast charge’ or ‘heavy-duty charge’, enhancing collective performance when compared with traditional battery packs.

Screen Shot 2015-10-05 at 16.59.34Detecting user activities, such as word processing, email or video streaming for example, the smart system can judge which is the most efficient battery to apply. The technology also employs machine learning techniques to learn an individual’s usage profile, so it can work out how best to extend battery life based on personal habits.

‘We are tying personal assistants like Siri, Cortana, and Google Now with SDB. These assistants understand user behavior and the user’s schedule and by using this information, an OS can perform better parameter selection,’ the paper reads.

The study goes on to quote a solution to wearables charging which often struggles to manage the need for bendable batteries, which have excellent low power handling, with consumer demand for high power applications. The researchers claim that a hybrid battery system which combines a bendable battery with a Li-ion battery and uses an SDB algorithm, could allow a wearable OS to minimise inefficiency, utilise strap space and maintain the ability to execute high power workloads such as GPS tracking.

Screen Shot 2015-10-05 at 17.00.49Additionally, the technology is able to monitor charging behaviour, recording when a user typically plugs in their device and how long for, in order to improve efficiency. Power for a user who rarely unplugs an external battery, for example, would be best drawn simultaneously from both internal and external batteries, reducing internal losses and increasing the energy delivered to the system. In this usage case, results of the simultaneous power parameter showed a 22% average improvement in battery life. However, this gain would not be achieved for a user who only plugs in for short periods of time – hence the importance of SDB adaptation to specific user behaviour.

The cost of the SDB system, according to Chandra, will not be ‘significant’ as weight and volume are not compromised. The system can be implemented by simply expanding the functionality of a device’s micro-controller and exposing existing battery packs to the OS – ‘there is no additional cost or bulk because of SDB.’

The team is expected to present their findings at the Symposium on Operating Systems Principles this week, along with working prototypes. Although the system remains in the field of research for now, the researchers hope to have it installed in consumer products in the near future.

Looking even further ahead, Chandra suggests the technology could be applied to smartphones, electric vehicles, data centres and any other use case powered by a battery.

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