Are fast USB chargers really fast?

[slicksilver]

or is this a marketing gimmick? I have two phones i.e. Samsung and Blackberry and would like to get a charger which charges faster than the factory supplied. Both have micro usb connectors.

Thanks

 

[BrightCandle]

Most USB charging is done at usb current limits, which is quite a bit less than what a phone battery can take. What fast chargers so is break the usb spec and provide more current. They aren't a gimmick, they really can be faster than charging from a pc, but just bare in mind most phones today come with a plugin transformer ending with a micro USB and those are probably already a "fast charger"

 

[fuzzybabybunny]

How fast something charges is based off of the milliamp (mA) rating. Standard USB from your computer charges at 500mA. A "fast" charger is usually anything above 500mA, the most common being 1A / 1000mA.

So if you have a 2000mAh battery it would take 4 hours to charge on a 500mA USB port while it would only take 2 hours to charge with a 1A fast charger.

You can see the mA rating on the chargers. It will be on the packaging and always on the charger itself: Output 5V 1A (for example)

 

[slicksilver]

How fast something charges is based off of the milliamp (mA) rating. Standard USB from your computer charges at 500mA. A "fast" charger is usually anything above 500mA, the most common being 1A / 1000mA.

So if you have a 2000mAh battery it would take 4 hours to charge on a 500mA USB port while it would only take 2 hours to charge with a 1A fast charger.

You can see the mA rating on the chargers. It will be on the packaging and always on the charger itself: Output 5V 1A (for example)

Great! So I think I'll get one. Which ones are reliable?

 

[BrightCandle]

I was reading a review on this in the last month or so. Alas I can't find it but the take away was that most chargers were utterly rubbish, including those from the big manufacturers. I think apples one was considered decent but beyond that I don't remember any positive reviews. Most produce jitter, lower am page than rated and other problem.

They did recommend one other than the apple charger however.

 

[luv2liv]

good to know 1Amp can charge faster! my gf swore it did charge her phones much faster but i didnt believe. i was afraid 1amp charger would fry the battery

 

[podspi]

good to know 1Amp can charge faster! my gf swore it did charge her phones much faster but i didnt believe. i was afraid 1amp charger would fry the battery

The amperage rating is a max number, the actual number is determined by how much the phone decides to pull (up to the max). What can fry your phone is going out of spec with the voltage.

 

[s44]

Btw, the stock Note 2 charger is 2a.

 

[Jinny]

How fast something charges is based off of the milliamp (mA) rating. Standard USB from your computer charges at 500mA. A "fast" charger is usually anything above 500mA, the most common being 1A / 1000mA.

So if you have a 2000mAh battery it would take 4 hours to charge on a 500mA USB port while it would only take 2 hours to charge with a 1A fast charger.

You can see the mA rating on the chargers. It will be on the packaging and always on the charger itself: Output 5V 1A (for example)

Theoretically yes. However the phone/gadget will only pull whatever it needs and not more. most phones will pull only 700mah, so as long as your charger provides at least that amount, you're good. In this case, a 1A charger will not charge any faster than a 2A charger because the phone only pulls 700maH.

 

[maniac5999]

Btw, the stock Note 2 charger is 2a.

Interesting. That explains why my Note seems to charge much faster at home with the 2A charger than at work with the old wall-wart I've been using, which is from my Motorola Triumph. The dumb Motorola charger's only .85A

 

[lothar]

TouchPad charger.
I still have 4 sealed in a box somewhere when I got it on sale for $5 each, plus the original that came with it.

 

[vshah]

best would be an oem tablet charger, like a touchpad charger or a nexus 7 charger.

 

[Suspicious-Teach8788]

you guys realize half of this is the charger, the other half is your device. The SGS2 for example can only take in 650 mA. 2A charger won't save you there. My iPod touch didn't charge at 2A even with the iPad brick.

 

[sjwaste]

you guys realize half of this is the charger, the other half is your device. The SGS2 for example can only take in 650 mA. 2A charger won't save you there. My iPod touch didn't charge at 2A even with the iPad brick.

I came here to post this.

 

[Viper GTS]

you guys realize half of this is the charger, the other half is your device. The SGS2 for example can only take in 650 mA. 2A charger won't save you there. My iPod touch didn't charge at 2A even with the iPad brick.

There are two parts to this:

1) The charger has to tell the device it's charging on AC and to take whatever it wants (by shorting the data pins)
2) The device then puts itself into AC charge mode and will pull 1A or whatever the device max is

If the above both fail then you're looking at the usual 500ma charge rate.

In my experience most detachable cable type USB chargers will not successfully identify as AC without a charge-only cable. A high output charger with integrated cable will generally produce appropriate AC charging rates.

Viper GTS

 

[fuzzybabybunny]

There are two parts to this:

1) The charger has to tell the device it's charging on AC and to take whatever it wants (by shorting the data pins)
2) The device then puts itself into AC charge mode and will pull 1A or whatever the device max is

If the above both fail then you're looking at the usual 500ma charge rate.

In my experience most detachable cable type USB chargers will not successfully identify as AC without a charge-only cable. A high output charger with integrated cable will generally produce appropriate AC charging rates.

Viper GTS

My question is this:

While the device is just sitting there on idle it could limit the charge rate to 700mA or whatever. When it is actively being used, screen on full brightness, whatever, would the charge rate go up to 1A to compensate for the added power draw? In this case a 1A charger would be well worth it. I've had some 500mA chargers and even while plugged in the phone was STILL decreasing in battery as I was actively using it.

 

[Thegonagle]

There are two parts to this:

1) The charger has to tell the device it's charging on AC and to take whatever it wants (by shorting the data pins)
2) The device then puts itself into AC charge mode and will pull 1A or whatever the device max is

If the above both fail then you're looking at the usual 500ma charge rate.

In my experience most detachable cable type USB chargers will not successfully identify as AC without a charge-only cable. A high output charger with integrated cable will generally produce appropriate AC charging rates.

Viper GTS

This...

The device has a maximum it can possibly try to pull from an AC charger. If the OEM charger is rated at 1A (as most Android phones are supplied with), a 2A charger most likely won't do anything for you.

A 750 mA charger that is identified as "AC" could potentially overheat or burn out if the phone tries to pull 1A, but it's possible that the phone's charging circuitry backs off on the charge rate if the charger's voltage drops for lack of ampacity. (Edit: I don't know for sure whether this is the case, but it makes hypothetical sense.)

EDIT to add: The .5 A charge rate is a "safety" charge, intended first and foremost not to damage the equipment it's plugged into. The phone won't draw more than that if it thinks it's plugged into anything other than a purpose-built charger. As far as chargers go, it's probably best to stick to the manufacturer's spec or greater when using a non-OEM (NOEM?) charger.

 

[OBLAMA2009]

i was checking out usb charger in walgreens the other day and i noticed that one of the chargers had two usb ports, one was labeled 1 A (labeled "iphone") and the other 2 A (labeled "ipad"). what would happen if you plugged your iphone into the ipad usb port?

 

[Thegonagle]

i was checking out usb charger in walgreens the other day and i noticed that one of the chargers had two usb ports, one was labeled 1 A (labeled "iphone") and the other 2 A (labeled "ipad"). what would happen if you plugged your iphone into the ipad usb port?

It would charge at the normal rate for an iPhone, with the charger having juice to spare.

I use an Apple iPad 2A charger for my iPod. My iPod doesn't charge any faster with it compared to a 1A charger.

 

[ringtail]

Seems to me it depends on the condition (age) of the battery.

In a new device charging is impressively fast.

In an old device the battery is somewhat degraded and recharges slower.

 

[hans007]

I've got a 1amp charger. The andru charger that looks like a little android robot. Yes it cost like $25.

That said when I had a gnex it seemed to charge almost twice as fast on it as the bundled 700ma chargers.