/ Technology

Laptop and phone always plugged in? That’s £60 down the drain

We’re apparently wasting £134 million a year by overcharging our gadgets, according to a study by energy firm Eon. Do you leave your mobile phone or laptop plugged in well after it’s fully charged?

Eon’s study found that one in five of us leaves our devices plugged in even after the battery is full because we’re scared of running out of power when we leave the house. Another one in ten of us are simply too lazy to pull the plug.

I’m guilty of overcharging, especially when it comes to my beloved netbook. I have a one-and-a-half hour commute from Sussex (each way) to Which?’s London HQ and pass the time by trying to write the book I’ve been working on. So I always make sure it’s plugged in as soon as I get home and just unplug it when I leave.

On occasion the plug’s come loose from the wall at home and I’ve run out of charge on my way in. It’s not critical, but without this distraction the journey does seem to take twice as long. To me a charged netbook is essential, and if that means leaving it plugged in, so be it.

Overcharging won’t give you more power

In reality there’s no need for me to overcharge my netbook at all. On a full charge it’ll last for two full days’ worth of journeys – around six hours – a massive leap from the 1.5 hours of my first portable device (a Toshiba Libretto).

So why is it that, like me, 41% of those surveyed by Eon are overcharging their laptops? I suspect that part of the answer lies in the fact that a laptop’s battery barely lasts as long as we expect it to, or as long as manufacturers claim it will.

Still, overcharging isn’t going to buy you any more time – if anything it’ll degrade the performance of your laptop’s battery faster, not to mention the estimated £60 per year Eon says you’re racking up on your energy bill.

Alternatives to overcharging

Eon’s survey reveals that 46% of us would stop overcharging our gadgets if we were aware of the savings we could make. But for me it’s as much about ensuring I have enough travelling time with my netbook as it is about saving money. Call it paranoia if you will!

There are, however, other strategies you can use to save battery life on your laptop. We recently listed some battery saving tips in our Which? Computing magazine, including lowering your screen’s brightness and switching off wi-fi. You can find a selection of these tips on the Which? Tech Daily blog.

As for me, I’m going to make a New Year’s resolution to stop overcharging my netbook – though I’ll be keeping a spare charger in the office as well as at home… just in case.

Anon the mouse says:
4 January 2012

If you charge a device that has a USB lead from a device with power, ie phone from the TV. It reduces your energy consumption as you are using energy that is used by the larger device anyway.

Even if the USB port says engineer use only it still has power.

I cant seem to find any details of how EON worked out this £60 pa wastage figure.
I make this a continuous energy consumption of 50 watthours.
A quick check with a netbook and an old laptop suggests that to be wasting this amount you would need to leave 3 laptops plugged in continuously or an awful lot of mobile phones ! ( Remember if you are actually using the laptop the energy isnt being wasted)

As with many of these energy wastage “scare” stories the figures quoted are often extreme examples rather than what the average household is wasting.
While I agree with encouraging people not to waste energy, these stories often result in a false sense of complacency as people think they dont have to do much more as they already “Unplug their phone chargers” when not using it !

I fully agree with you, rarrar, assuming you meant a continuous power consumption of 50 watts (not watt hours). I find the figure hard to believe and would like to challenge whoever came up with it to show exactly how they worked it out. In fact, most laptop batteries have built-in “intelligence” and they reduce the power they draw from the adaptor to a trickle as soon as they have fully charged. In turn, the adaptor reduces the power it draws from the wall socket to a minimal amount (a few watts maximum).

Just being pedantic – cost is based on 50 watthours of energy every hour which is of course 50 watts power used continuously .Unlike you most people dont understand the difference between power and energy and the concepyt of being charged for the energy used rather than the power used , so I always have difficulties being correct but understandable.

Just rechecked netbook – 38 watts in use and charging dropping to 20 watts when charged, 19 watts when shutdown but charging dropping to 0 watts when charged.

I’m guilty of overcharging, right now as we speak my laptop sits at home plugged in at my desk.

I also leave my phone plugged in overnight too, don’t tell the electricity police! 😮

It’s not unheard of for staff to charge up their mobiles and laptops while at work thus increasing their employer’s costs which have to be passed through to consumers. Of course, that wouldn’t happen at Which? because [a] it is energy conscious, [b] it exercises good budgetary control, and [c] has a tendency to being consumer focussed.

Many of the chargers now are quite clever and use negligible current when the Phone/toothbrush etc is charged. This is around 2 milliamps on my HTC phone. Even at EONs rates that is about £6 a year at 15 pence per KWhour) (10 times less than EON s figure).
My philips toothbrush is less than a milliamp.so probable less tha £2 a year

I can imagine their might be some rubbish on the market that reaches the EON figure, those companies should be named and shamed. Rather than making us crawl around on our knees switching everything off all the time

Alastair, I think you are out by a factor of 10. I make it 63 pence a year:

Power = 2 milliamps * 240V = 0.48 W
Consumption in one year = 0.48 * 24 * 365 / 1000 = 4.2 kWh
Price = 4.2 * 15p = 63p

Actually, I think it is even less than that. You are using EON’s tier 1 (the expensive first N units) when in fact you should be using the cheaper tier 2 (since you are already using up all of tier 1 through the use of fridges, washing machines, kettles and irons.) So it’s actually about 2p a month.

John says:
6 January 2012

I agree with all the current comments on this (especially clint kink) – this research is rubbish. Mobile phone chargers changed to an intelligent design several years ago to prevent over charging. You can test this yourself – is the charger hot a little while after your device is fully charged? No? This means the transformer is not drawing as much power as it was whilst charging. I remember my old Nokia mobile phone chargers used to get really hot.
Also, regarding laptops. They only charge whilst needed. They will still be drawing full power from the mains after charging though – usually this is because most laptops have two different power modes – one for when plugged in and a power saving slower mode when running off battery power. This affects the performance of the laptop during use and most people will see the difference and prefer the full power mode (this is not related to screen brightness – although that is the most visible difference).

Ah thanks Clink Kirk for sorting out my Maths,
So as John suggests this “Research” can be ignored – me thinks. Does everyone agree?

What worries me is that Which doesn’t appear to have sought independent verification, but just reported the story without questioning it. Not a mark of great journalism.

John Fitz-Hugh says:
11 January 2012

Perhaps EON used one of their energy monitors to measure the consumption of the laptop or phone. As I keep telling people, these monitors indicate a much higher power consumption than the actual power consumption when they are monitoring loads that have a low power factor. Things like laptops and phone chargers have a low power factor. About a year or more ago I reported this via “Which Conversation” but could not get “Which” to take my comments seriously. As a long time subscriber to “Which” I found this annoying. “Which” subsequently went on to publish a further report on energy monitors which continued to ignore the severe inaccuracy of such monitors on low power factor loads.
I suggest “Which” gets its act together on this matter.

MY plug in power meter – which I used for my figures in an earlier post – has options for both Watts and VoltAmps (VA) and I have to be careful I have the right one selected or as John says you get a shock from the figures!

But even if EON used VA their calcs seem very very high.

How about a technical input from Which?

My meter is the same, and while I understand power factor I have no idea of how accurate my meter is or whether the kWh figure it records is a useful indicator of the cost of using an appliance.

The iPhone stops charging soon after it reaches 100% capacity and then runs on mains or USB power. This is indicated by the lightning bolt symbol changing to a plug symbol. When I plug in my iPhone to charge overnight, it takes around two hours to charge, and I specifically want it to continue running on mains power for the rest of the night until I leave home in the morning. Please distinguish between overcharging and running on external power; the two are different.

Battery chargers should have an indicator when charging that goes out and the power cut when the product is fully charged.
I am guilty of leaving things plugged into the mains too long simply because I don’t know whether they are fully charged or not.
I have a torch that cost about £25 where the charger has an indicator that changes colour when fully charged. Recently I needed a new charger for a garden tool. The non-indicator version cost around £15. The intelligent version cost about £75. Why so much dearer?