Why not a real technofix?

A charger that switches itself of at the AC-side when the batteries are full.

That will work for 100% of the owners.

I've always been wondering the same thing, Pieter.

The current chargers - like computer power supplies - are usually very inefficient mostly because of price. It's probably also why chargers don't switch off automatically.

To change that would probably take a new regulation.

I think it would require the device and charger to talk to each other to turn off when done charging. That adds cost and complexity. An easier solution would be to incorporate a timer on the charger and just shut off after max time for charge. Or do it yourself with a plug in timer.

Well, a plug-in timer would only work if it had a kitchen-timer-style of movement. A standard motor-driven plug-in timer would be as much of a constant drain as the transformer. A built-in timer would be most user friendly with the turn-on button located right on the phone's plug. A button on the wall wart would be too inconvenient for many.

A simple circuit could sense when the phone whas plugged in and trip a relay to engage the AC within the block.
OR, a third wire from the phone plug to the transformer block would carry the signal from a microswitch. Same thing.
Perhaps if someone like the UL outlawed always-on transformers.....with congress's help....Time to write letters!

hmm...maybe you should read this huh? mr. 24/7 cell phone charger.

I have a commute which is long enough to charge my phone in my car (hybrid).

I don't think I've charged it at home in ages.

Is there a negative environmental impact from charging in my car (other than /beyond the impact the car would already have) ??

I think this is a load of BS.
most chargers have the ability to tell when the battery is full and immediately stop charging ...most devices are like this ( including PDAs, ipods, ect..)..... what are these people talking about?

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editor note: Actually, most chargers do not. Maybe those that you have do, but that's the exception. A way to test that is often just to touch a charger with nothing plugged in and see if it gets hot.

Telling if something is done charging and actually stop drawing energy into the transformer are different. The devices know when they are done charging, not the transformers. Could go to electronic transformers instead of magnetic too. But that costs more.

I have the "kill-a-watt" device. When my cell phone charger is plugged in with nothing charging to it, I get 0 watts of power being used. When my cell phone charger is plugged in with a full charge, I get 0 watts of power being used. I have the moto v360 that I got a few months back. Recharging batteries is painless and efficient. Are you sure unplugging the charger will save any power?

Someone tell my GF that leaving the charger plugged in, BY ITS SELF does not use electricity.

She doesn't seem to get that.

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ed note: Actually, sometimes it does. A quick way to find out: touch the charger when it's plugged and see if it gets warm.

What the Ed says about coil losses through heat is true of big old linear power supplies, yes. However, most mobile phone chargers these days are switched mode power supplies, which means they don't have coils (and there for reactance losses like heat). A switched-mode power supply does 'shut down' when not in use, merely drawing enough electricity to keep a tiny capacitor topped up. So almost too small a current to measure.

Much, much better to worry about using energy saving lights, turning off TVs or amplifiers, taking the bus, not buying food flown halfway across the world, etc. etc.. I actually fart, every day, more damage to the environment than my mobile charger being plugged in does.

Let's be generous, and say my phone charger draws 0.1W when not in use (it's less, but my gear won't measure that low). The average Brit's energy requirement is 5KW (including non-electricity energy like driving and so on, figure from govnt stats), which means just to offset my personal energy use, 50,000 chargers need unplugging, 24 hours a day. To offset power requirements of 60,000 Brits, some 3 billion chargers need unplugging. Now imagine each of those 3 billion people replaced one incandescent light bulb with a flourescent. That one bulb saves (say) 50W each. That gives us 1.5 Terawatts saved. THAT'S TEN POWER STATIONS. Priorities, people. If you're getting 3 billion people to do one thing, let's get them to do one thing that makes a big difference.

Of course, there aren't even 3 billion mobile phones in use. I doubt that many people even have access to electricity, let alone mobile phones. A BBC article suggested there may be 1 billion mobile phones in use worldwide. I don't have numbers to back this up, but I'll bet there are 3 billion incandescent light bulbs in London alone.

Someone should figure out (showing their working) whether the energy cost of making a 'talking' power supply is more or less than the energy cost of sticking with what we have and keeping that voltage capacitor full. My money would be on making new power supplies (cost of design, development, factory retooling, parts, extra shipping due to increased weight/size, etc) being considerably more energy hungry than otherwise.

so cool ,bu i just buy a solar charger at sourcingmap

ah
Regret!!

Just dropped by to see what the truly braindead are worried about today.

Basic science class. You envioro-zombies missed a lot in your substandard educations.
The transformer in a phone charger is using electricity when the phone is plugged in, and the battery contact points are completing the circuit. When the phone is not plugged, in the circuit is not complete, therefore no electricity is being used.
A note of caution:
However, if plugged in, and short circuited across the charger's contact points (by something metal or even spilled liquid) a small possibility of a fire occuring. (with a fuel source).
Now, I'm sure you probably don't want to hear why global warming is a scam to get your money.
But hey, you were already stupid. Who am I to stop you from saving the planet.
Guffaw
YOU idiots