One of the comments on this blog made me start wondering about the little parasitic devices we have all over the house. I've always assumed that they drew so little power they wouldn't matter when compared to to the kilowatt guzzling motors and heating elements we have in the larger appliances. One little device that annoys me is the cell phone charger. Every time the phone gets to a full charge it tells me to unplug the charger to save energy. Sheesh, leave me alone, let me worry about how much power I'm using.
However, the commenter said his measuring device recorded 15 watts for several of his devices. If I can confirm that, I may have to think about doing something since I have a bunch of them around the house. So, I'll take on an annoyance and see what the power usage really is for my cell phone charger.
![]()
![]()
![]()
However, the commenter said his measuring device recorded 15 watts for several of his devices. If I can confirm that, I may have to think about doing something since I have a bunch of them around the house. So, I'll take on an annoyance and see what the power usage really is for my cell phone charger.
This little phone sucks 12 watts when it first starts out, so I need a really good wall wart that can supply over two amps to get the quickest charge. Since I used the 'genuine' Samsung charger for this test, I let the phone drain down to (approximately) the same point and tried one of those 'Samsung' chargers that are available on Ebay.
Don't let the scale confuse you, this charger never gets over 1 watt. Since my granularity (using this monitor device) is 1 watt, it could have gone a little higher or lower and still read this way, so I plugged in an amp meter in series and watched a while and it didn't ever go over 500 mA. It doesn't have the stair steps of the real Samsung charger and took much longer ( less than an hour compared to over 2.5). It looks like buying a real brand name may result in much, much better performance. However, how the heck do you tell if it's really from the manufacturer? Both of them are labeled 'Samsung' and they are the same form factor. The ratings on the side are the same, so how do us folk out here in the world tell the difference?
I don't have an answer to this, and I'm certainly not going to buy a few hundred different ones and try them out. I'm seriously thinking about making a load to test these things before I try to depend on them for anything. If they fail the test, I'll do some serious complaining to the supplier. The other thing I'm thinking about is putting together a power supply that will give me 5V at three amps reliably. This would be useful to see how the charge characteristics of the phone look when it has enough current available.
Just for fun, I weighed each of them. The real Samsung charger weighed 37 grams and the other one came in at 25 grams. The real one has 12 grams more stuff in it, or thicker plastic. Since I plan on using the fake for other things, I'm not going to dismantle it ... yet. But here's a picture of the two of them:
The fake is the black one.
Just to let you folk know though, there are two differences between them. 1. The real one has a UL certification on it, the fake doesn't. That's really easy to overcome, they simply add another certification stamp to it. 2. The fake says 5.0 volt at 2 amp, and the real one says 5.3 volt at 2 amp. Once again, that's easy to overcome. I've already mentioned the weight, but no supplier tells you the weight of the device.
Anyway, I started this as an investigation into parasitic power and wound up researching chargers and their capabilities. Sigh. At any rate, let the buyer beware.