# Leaving cell phone rechargers ibn the wall **URL:** \ **Category:** Factual Questions\ **Created:** [July 4, 2009, 11:26pm UTC](https://boards.straightdope.com/t/leaving-cell-phone-rechargers-ibn-the-wall/501937 "2009-07-04T23:26:48Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![copperwindow](https://avatars.discourse-cdn.com/v4/letter/c/4af34b/32.png) [@copperwindow](https://boards.straightdope.com/u/copperwindow)\ **Post date:** [July 4, 2009, 11:26pm UTC](https://boards.straightdope.com/t/leaving-cell-phone-rechargers-ibn-the-wall/501937/1 "2009-07-04T23:26:48Z")
I heard from a very unreliable source that leaving cell phone rechargers in the wall when not in use wasted electricity. Can any dopers verify this? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [July 4, 2009, 11:37pm UTC](https://boards.straightdope.com/t/leaving-cell-phone-rechargers-ibn-the-wall/501937/2 "2009-07-04T23:37:52Z")
Yes, it does. But you would save more electricity in one day by turning your AC up 1 degree than you would save in a year by unplugging your cell phone charger. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [July 4, 2009, 11:40pm UTC](https://boards.straightdope.com/t/leaving-cell-phone-rechargers-ibn-the-wall/501937/3 "2009-07-04T23:40:26Z")
They use a tiny amount which is disipated as heat. The hotter it feels the more it is using but, in any case, the amount is negligible. ---
**Author:** ![TBG](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@TBG](https://boards.straightdope.com/u/TBG)\ **Post date:** [July 4, 2009, 11:43pm UTC](https://boards.straightdope.com/t/leaving-cell-phone-rechargers-ibn-the-wall/501937/4 "2009-07-04T23:43:34Z")
It’s not unique to phone chargers, BTW. Most (all?) power cords with a little box somewhere on them to convert AC to DC, whether as a wall wart or as soap on a rope, will continue to use some power for as long as it’s plugged in. ---
**Author:** ![Claire\_Beauchamp](https://avatars.discourse-cdn.com/v4/letter/c/ec9cab/32.png) [@Claire\_Beauchamp](https://boards.straightdope.com/u/Claire_Beauchamp)\ **Post date:** [July 5, 2009, 12:13am UTC](https://boards.straightdope.com/t/leaving-cell-phone-rechargers-ibn-the-wall/501937/5 "2009-07-05T00:13:03Z")
It’s called vampire power: > **[How Vampire Power Works](https://electronics.howstuffworks.com/everyday-tech/vampire-power.htm)** > > Forget the wooden stake -- the only thing that stops this vampire is unplugging your electronics. Vampire power sucks energy at a rate that would make anyone scream in horror. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [July 6, 2009, 2:19am UTC](https://boards.straightdope.com/t/leaving-cell-phone-rechargers-ibn-the-wall/501937/6 "2009-07-06T02:19:08Z")
I bought a [Kill-a-Watt](http://www.p3international.com/products/special/P4400/P4400-CE.html) meter a couple of years ago and measured the consumption of various devices in my house. I measured when the devices were on/in use, and when they were in “standby” mode. My cell phone charger uses 3 watts when actually charging a phone, and 0.5 watts when it’s plugged in with no phone attached. Assuming this charger is plugged in 24/7 but spends most of its time NOT charging a phone, it would add a whopping 4 cents to the monthly electricity bill. (take watts, multiply by 0.072 to estimate dollars per month. This assumes a rate of ten cents per kilowatt-hour from the power company.) It’s hard to argue that this is anything other than a waste, but on The List of Ways That I Waste Resources, it’s pretty far down there. TV? 11 watts on standby; 79 cents a month. VCR? 5 watts. The surprising one for me was my computer’s speakers. This is a powered-speaker system from Logitech (4 satellites + sub), and I leave it on all the time. Was amazed to see that it draws a steady 23 watts, accounting for about $1.65 of our monthly electricity bill. Yikes. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [July 6, 2009, 1:06pm UTC](https://boards.straightdope.com/t/leaving-cell-phone-rechargers-ibn-the-wall/501937/7 "2009-07-06T13:06:22Z")
I just got a digital cable box. It has vents on top. But I turned it off one evening and inadvertently left a TV schedule on it and the next morning, it was quite warm to the touch. I don’t know how much power it is using in the off mode, but it is clearly not trivial. ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [July 6, 2009, 3:34pm UTC](https://boards.straightdope.com/t/leaving-cell-phone-rechargers-ibn-the-wall/501937/8 "2009-07-06T15:34:26Z")
> [@Hari\_Seldon](#): > > I just got a digital cable box. It has vents on top. But I turned it off one evening and inadvertently left a TV schedule on it and the next morning, it was quite warm to the touch. I don’t know how much power it is using in the off mode, but it is clearly not trivial. Significant, probably. The one Comcast gave me pulls over 20 watts on standby, measured with one of the previously mention cheap meters, which seems excessive. Modern LCD TVs on standby draw very little. ETA: For example, my Samsung LCD TV draws \< 1 watt on standby, as measured. Samsung claims some figure like 0.6. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [July 6, 2009, 5:36pm UTC](https://boards.straightdope.com/t/leaving-cell-phone-rechargers-ibn-the-wall/501937/9 "2009-07-06T17:36:23Z")
All of those little devices do draw power non-stop, but in the case of things like phone chargers, unplugging and plugging them in as needed will probably wind up costing you more in the long run after you wear out the contacts in the outlet from all of that plugging and unplugging. Devices such as digital cable or satellite TV receivers do run warm to the touch even when “off” but the time it takes to boot those things up would fast become a severe annoyance - my DVR takes nearly five minutes to boot up, scan for satellites and download the program guide before it’s ready to tune to a channel. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [July 6, 2009, 5:41pm UTC](https://boards.straightdope.com/t/leaving-cell-phone-rechargers-ibn-the-wall/501937/10 "2009-07-06T17:41:33Z")
I have a mass of wall warts plugged into the power bars behind my desk: computer, cellphone, monitor, external hard drives, sound system, etc, etc, all of which consumed power on standby. I switch them all off there when I leave the apartment or go to sleep and don;t want to continue listening to music or whatever. This cut my power usage by around five percent. Granted, I don’t have a lot of _other_ power usage other than a few lights and appliances, plus the fridge and stove.