Not All USB Power Is Created Equal

jfruh writes "We've reached a point in our electronic lives where most of our gadgets draw power from a USB cable, and we have lots of USB ports to choose from — some of which live on other gadgets, some of which live on adapters that plug into your wall or car. But those ports supply wildly varying amounts of power, which can result in hours of difference in how long it takes your phone to charge. The Practical Meter, the product of a successful Kickstarter campaign, can help you figure out which power sources are going to juice up your gadgets the fastest."

Comments

Re:Or use what already exists

[Charliemopps]

Oh my God people, turn in your fucking geek card:
http://www.amazon.com/Etekcity%C2%AE-Digital-Multimeter-Voltmeter-Ohmmeter/dp/B00B7CS3UY/

Put it in series with your device and set it to amps. It also has 1000 other uses besides checking that the numbers on the side of your USB adapter are accurate.
Also this, AND the above mentioned devices will only tell your the voltage your device is currently drawing. You could have a 2amp capable USB port but if your device only draws .5 at max load, that's all you're going to see.

I recommend USB adapters rated at least at 2 to 4amps (or in the 12 to 24+ watt range) My phone doesn't generally draw more than about 2. Less than 2 and you'll likely use more power than you'll charge with so if you've got it in your car listening to music it'll die even while it's plugged in. The common grab bag 1amp plugs you can get at the checkout are garbage.

Let's talk

[Blahblagger]

Let's talk about a real problem here. Not how fast devices charge and a little dingbat meter, but about how ubiquitous USB is, many devices fail to live up to part of that when it comes to charging, that is being -UNIVERSAL-. I have the following devices iPhone 4 Motorola Admiral(work) Asus Transformer Prime Infinity(fuck you Asus, this was supposed to be premium, why is it[Tegra 3] and Android so shit? Also, your tech support sucks) iHome speaker(charges via USB) Kindle You know what? Of them, the Motorola Admiral and the Transformer fail to charge from some chargers. I don't care if it takes 24 hours to charge for the tablet, it should be FUCKING CHARGING if I plug it into a USB port. And because of the ubiquity of things that charge via USB, I recently got a 4 port charger... and I can't even charge half my devices on it.

Re:Apple vs. Other Devices

[jo_ham]

Your daughter is correct. Your dongle is a POS.

None of my iDevices have ever refused to charge on third party USB power supplies, but then I've never used a cheap shitty one. I have charged both iPhones and iPads from everything from my car's head unit (Kenwood, with USB cable in glove box), a Kindle charger, various laptops and desktops of assorted brand, a "no brand" cigarette lighter adapter that came with an FM transmitter thing for the car, and an android phone power supply (I forget which one now, it was some time ago).

So, either you're ignorant of what is actually going on here (you did say you are an Apple abhorrent), or you have a crappy adapter that the iPhone is shutting off to protect itself from.

I assume you're going for some sort of "Apple is crap/only works with expensive proprietary stuff they sell you" angle, but you're pretty wide of the mark. The fact that you think your adapter is beyond reproach is also slightly concerning, although I guess the worst it could do if it burns out is just to stop working (I have seen this happen with a cheap cigarette lighter adapter splitter when it pulled too much current).

I would suggest checking it out for your own safety, but you can probably just smile if it melts and remind yourself that at least you don't buy Apple products, so you're somehow ahead.

Re:Or use what already exists

[Khyber]

"Oh my God people, turn in your fucking geek card:"

No, actually you should you fucking 7-digit nitwit. Here's why:

"I recommend USB adapters rated at least at 2 to 4amps"

USB 2.0 (currently the most ubquitous of the USB specs) does 500mA.

"My phone doesn't generally draw more than about 2."

Even USB 3.0 limits to 1.5A charging. USB 3.1 limits 5V devices to 2A.

4 amp rated charger? You won't even get 4A through USB for charging your shitty 3.7V phone.

Oh, and anyone worth their fucking salt doesn't need the multimeter. We know how to do the math by hand, unlike you digitally-crippled morons.