There were several reasons why I bought a new iPhone 8, including a collapsing battery in the old iPhone 6. The iPhone 8, however, can perform a party trick that the iPhone 6 cannot. I had forgotten about this until Tigger made me a present of a Qi charging pad: the iPhone 8 represents Apple’s first foray into the brave new world of wireless charging.
Other manufacturers had already adopted wireless charging and your phone, dear reader, whether or not it is an iPhone, can probably use this method of battery replenishment. Do you find it useful? I do, up to a point.
To start with I was intrigued by the novelty but there are a few practical advantages too. Once you have plugged your charger into the power socket and tucked away the wire tidily, you can simply put your phone on the pad to recharge it. You can pick it up and work with it without the inconvenience of unplugging it or coping with the trailing wire. Some public venues, which have for a long time provided power points and even USB sockets for use by customers, now also offer wireless recharging. One of these is the Starbuck’s chain of coffee shops. This means that when you are out and about, you can recharge your phone for the cost of a cup of coffee. This also dispenses with the need to carry a charging cable – and perhaps a charger and plug as well – with you.
Apart from these minor advantages, though, wireless charging does not really take us very far. We still do need a charger to restore a flagging battery and the battery still remains the mobile phone’s most vulnerable feature. What is needed to end the slow torture of constantly recharging our devices is a new approach. The good news is that one is on its way to us.
The sort of wireless charging that we currently use with our phones is called “near field” because the charger can transmit its power only over very short distances. You need to place your phone very close to the charger, preferably in contact with it. Even an extra thick phone case can prevent recharging from taking place.
However, there also exists “far field” power transmission in which electrical power can be transmitted over larger distances. The problem with this is that so far, the power has needed to be “aimed” at the receiver which obviously makes it impossible to use with a mobile phone that moves here, there and everywhere with its busy owner.
Now consider radio and TV. The signal for these is sent from high-powered transmitters and travels far and wide to be picked up by receiving devices, that is, your radio or TV set. So far, radio and TV signals carry only data, namely the encoded sound and pictures of your radio and TV. The receiver needs its own power to decode the signal into a form useful for listeners and viewers.
What if, instead of just data, broadcast signals could also carry power? This would mean that your radio would receive both the data and the power to decode it from the broadcast signal. Is this possible? Yes, it is, and this represents the next big step in powering our mobile phones: power sent over wifi.
But wait: if my phone is being recharged by wifi, does it need to be charged up in the first place? The answer is no and this is the good news: once power by wifi is fully implemented, phones will not even need batteries! They will simply work when exposed to wifi whose signal will carry both data and power. The most vulnerable feature of mobile phones, the battery, will be gone for ever. So will chargers, portable power banks and the cables to connect them to our phones.
The only problem that I can see with this is that if you had no signal – as might happen as it does now when you are in remote areas – you would not be able to use the phone at all. So if you wanted to play Tetris while camping on top of a mountain you would perhaps be wise to take a wireless power bank with you!
When will power by wifi become generally available? Ay, there’s the rub: I don’t know. The sources I have consulted don’t know either. So far it is a tantalising glow just over the brow of the next hill and it’s anybody’s guess when it will become a reality.
Nor have I seen any estimates of the cost to consumers of using such a system. It will call for large investment in infrastructure, which the customer will pay for, one way or another, and there will be running costs. Presumably we will have to pay for the power we use much as we pay for domestic power now. Proponents of power by wifi claim that it is far more efficient, and therefore cheaper in the long run, than present forms of power supply.
Won’t we need new devices to take advantage of wireless power? The article I have cited below claims that existing devices could be retro-fitted with power receivers. Nice idea, but I honestly cannot imagine Apple, Samsung, Google et al. passing up the chance to sell us new phones. Apple certainly never offered to adapt my iPhone 6 to take advantage of wireless charging! No, I think we shall have to stump up for new model.
Finally, would all that power sloshing about constitute a danger to health? People who claim to suffer from electromagnetic hypersensitivity will no doubt feel concerned by the prospects but proponents claim that it is safe.
For more details, see 11 Myths About Wireless Power