A study by power company Eon has found that British households waste £134 million a year in electricity costs by overcharging mobiles phones and laptop computers.
The company described leaving devices plugged into power as ‘overcharging’ and claimed that it decreases the lifespan of batteries and increases electricity charges. The claims are made in a study seen by the Daily Mail which doesn’t appear to be available publicly.
"It’s crucial that we keep an eye on how much money and energy we’re wasting keeping them charging when we don’t need to," said Eon representative Emma Thompson according to the Daily Mail report.
One can only assume that over the festive period the authors of the report didn’t feel like checking in with any remotely qualified engineers that would point out that the vast majority of chargers, and all chargers for anything with a lithium-chemistry battery like phones and laptops, stop charging the battery when its full.
If they didn’t, the battery would dangerously overheat. For batteries using nickle cadmium or nickle metal hydride chemistries, typically chargers will fast charge and then switch to a trickle when the battery is near full. That trickle is important to maintain the cell capacity, lest you want to pick up your device and find it has no charge at all.
"When you plug in a charger, think about how long it needs to reach full charge, rather than just leaving it on overnight," urged Thompson.
We rather suspect that people would rather grab their phone knowing it’s fully charged whenever the leave the house rather.
That said, there is a nugget of truth regarding wasting of power by leaving devices plugged into a charger after they have finished charging. A small amount of residual power will be drawn by the AC adaptor, usually a couple of watts or so.
In recent years there’s been a raising of awareness over so-called phantom power consumption of devices with unusually large power draw when in stand-by, such as set-top boxes. The upshot of that was that manufacturers improved their standby power consumption and it’s still an area worth highlighting.
However the report calling laptops and mobiles on 43 and 41 per cent (of what?) the most overcharged devices seems to err on the side of misinformation in search of a headline.
Ironically Eon was using the report to draw attention to their Energy Fit plan which consists of a power meter and a free smartphone app.
"Our App can be downloaded from the iTunes App Store if you’re an iPhone user or you can get it from Android Market if you’ve a smart phone," they said.
iPhone owners may be disappointed to learn that their phone doesn’t qualify as a smart phone.