Battery life – where next for the gadget Holy Grail?

Clare Hopping

Tuesday 23 September 2014

Mobile technologies have quickly evolved to make the smartphone and tablet as powerful as computers of just five years ago, so why do we still find ourselves charging our beloved gadgets once a day? Is it a matter of device overuse, or is it the fact that battery technology hasn’t evolved in line with our needs?

The main issue with battery technology is that it hasn’t moved at the same speed as other tech found in your smartphone or tablet.

Lithium-ion batteries haven’t changed since they were introduced in mobile devices in the 1990s. The graphite anode embedded in these batteries stores the power – and the physically larger the anodes, the larger the capacity. And as screens get larger and devices integrate more sensors and connections, such as NFC, Wi-Fi and HSDPA, their power consumption increases. The bigger and higher the resolution of the screen, the more power it sucks from the battery. Added to this, these new devices are much slimmer, so although the width and height of the batteries are bigger, the reduced depth has an effect on capacity.

So what’s happening now?

Amprius, a battery startup based in Silicon Valley, has found a way to install silicon into batteries that store power more efficiently and can increase battery life by around 20 per cent.

Silicon usually expands and contracts as it takes on and disposes of energy, and this can ultimately break the material – just like the freeze-thaw effect on stone. However, Amprius’s technology integrates a carbon-coated silicon cathode that protects the cells from damage. In testing, Amprius discovered that the batteries retain 80 per cent of their charge after 500 cycles – more than enough to keep your smartphone going on its 24-month contract.

Commercialisation of the batteries has started, with some manufacturers expressing an interest. But Amprius aren’t standing still. Earlier this year they secured $30 million in funding and will be putting that towards developing next-generation batteries that will store 50 per cent or more energy than the current lithium-ion batteries.

What can we expect in the future?

Another innovation that could benefit battery technologies of the future is Harvard student Eesha Khare’s supercapacitor energy-storage device. Khare claims that her battery can charge a mobile device in less than 30 seconds, retain power for longer and last a mammoth 10,000 charges.

The final innovation that potentially has legs to become commercially available for manufacturers is a solar panel behind your smartphone’s screen that will charge the battery whenever you’re in the sun. Wysips Crystal does exactly this and adds just $2 to a smartphone’s manufacturing costs. However, like any new technology that needs to be factored in, it’s dependent on manufacturers adding the technology during development.

A more likely option that doesn’t rely on the manufacturer to the same extent is wireless charging. Some public places are starting to implement a technology that allows you to charge your smartphone wirelessly from up to 30 metres. If you install a wireless charger in the office or at home, your phone will start charging as soon as you enter the building. Although some smartphones already do feature wireless charging, not all do.

What’s the answer?

Until manufacturers start implementing some of this technology into smartphones, the only option is to get used to charging your phone at least once a day.

But there are several things you can do to reduce the speed at which your phone discharges. First, reduce the brightness of your phone’s screen to an appropriate level. Next, turn off all connections (Wi-Fi, NFC, Bluetooth, GPS location services) when you’re not using them. Finally, close any applications you aren’t using. By running in the background, these apps suck your battery dry.

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