We all dread the moment our smartphone screen turns blank or a ‘low battery’ notification comes up, especially when we’re on the move and can’t find a charge point. But there are some wild and wacky, environmentally friendly ways – alternative and renewable – to recharge your phone without electricity. In recent years, researchers have come up with novel ideas involving physical and naturally occurring phenomena. There’s even a twist on the old idea of using the humble potato as a battery.
- Fruit and vegetables
There are plenty of videos on YouTube demonstrating how to use fruit and/or vegetables to make a battery charger. But this isn’t about using a couple of sticks of celery and an apple. More like hundreds of pieces of fruit and vegetables. In 2011, the artist, Caleb Charland, expanded on the classic school science project, the potato battery. The insertion of a galvanised nail into one side of a potato and a copper wire into the other side generates a small electrical current. Charland went further, fixing around 800 potatoes and apples to a wall and linking them all with cables, zinc and copper wires. The circuit generated a current of 20 mAH on average and around 6v, enough to charge a Nokia Lumia 930. Totally impractical although an interesting idea and oddly appealing as a work of art, but wouldn’t you rather spend time doing something more enjoyable?
If your instinct is to scream at your phone when it’s running out of battery – go on, scream as loudly as you can! In 2011, researchers at Sungkyunkwan University in South Korea developed a prototype that converts soundwaves into electrical energy. Using the sound-harvesting technology, batteries could be charged by many types of sound; the human voice, music, even the sound of traffic. The first prototype was able to generate 50 mV of electricity (sufficient to speak for a few seconds) from sound rated at 100 dB, equivalent to the noise created by a plane flying overhead, heavy traffic, or you screaming at your phone! The current is created by the vibration of zinc oxide cables between two flexible electrodes and may, some day, enable electricity to be generated more efficiently. But in the meantime, what happens when you become hoarse?
- Body heat
You can recharge your phone while you sleep by keeping it close to you instead of plugging it in at night. Vodafone researchers have developed the PocketPower, a pair of denim shorts that can, in eight hours, recharge your phone sufficiently for you to have 24 minutes of talk time. That’s provided the shorts are able to reach 37 degrees. Great if you’re on safari or chilling out in the Caribbean, but useless in the UK in the depths of winter. Alternatively, if you’d rather sleep with your phone than your partner, Vodafone has another product that would suit you very well. They have produced a super-charged sleeping bag which comes with a huge Power Pocket and converts body heat into electricity using thermoelectric material. Again, eight hours of snoozing will give you only 24 minutes of talk time, and it’s not great for your love life.
- Wind power
This gadget originated from the assumption that because wind farms generate a lot of energy, the concept could be adapted to power our phones. The drawback was that wind farms are always sited in very windy areas, not necessarily places where you live and work. Nevertheless, in 2010 Netherlands designer Tjeerd Veenhoven set to and created the iFan, which enables you to charge the battery using wind energy. You place your iPhone into an iFan charging case on the handles of a bicycle and ride it for six hours (!), by which time sufficient electricity will have been generated to fully recharge your phone. That is if the wind has been blowing continuously. An original idea, and environmentally very sound, but how many people have the energy, time or desire to cycle continuously for six hours? Although you could always cheat and suspend your phone from the car window when driving to work.
- Using a crank case
You could buy a crank case which enables you to recharge your phone using only the strength of your wrist. The device, the BoostTurbine 4000, features LED charge indicators which show how much battery life is left, and guarantees sufficient battery life to make a one-minute call or send some messages after cranking for just under four minutes. In a similar vein, the Roto Charger generates energy by impersonating a fishing reel, and takes one minute of cranking to produce three minutes of talk time. So in addition to recharging your phone, you also give your wrist muscles a workout. Then there’s the iYo yo-yo, designed by the Swede, Peter Thuvander, in 2010. The concept was simple –playing with the yo-yo charges a small battery inside – then use a USB to plug in your phone and power up. No surprise then that sales of this product were poor because people quickly became fed up of playing with yo-yos!
Mockery aside, all these devices contain sound, carbon-neutral, sustainable and renewable concepts, which may in time and with further technical development become much more practical and useful. Who knows, they may even become the norm in the next decade. In the meantime, though, why not invest in several portable chargers? Just make sure they’re fully charged to keep your phone always fully juiced. They’re great to take with you when you’re travelling and don’t want to have to queue for a charge point at airports and stations. There are many options depending on how much you’re willing to spend, and they range from the basic model that charges once up to those that can charge up to seven times on a single charge. Even better, go for a camp stove that has a USB outlet – its fan will generate electricity so your phone gets juiced up. Of course, you can cook food and boil water on the flame, doubly useful when there’s a power cut!