Phone chargers and amps

tinpanalley

Golden Member
Jul 13, 2011
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It's amazing how much contradictory info there is on this topic online. So, because I'm sure there are people more savvy here than other places, I thought I'd ask to see if anyone could give me a definitive answer...
Does it or does it not matter if you use a charger that has more amp output than your phone requires? With a phone that needs .75 A, is there a problem with using a charger that provides 2A? Obviously getting less than the required amps takes longer to charge, but if your current is stronger than needed, does the phone only take what it needs? And if so, then what are all these "smart chargers" doing that a standard charger can't do?

PLEASE help me finally get to the bottom of this. :)
Thanks!
 

shabby

Diamond Member
Oct 9, 1999
5,782
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Does it or does it not matter if you use a charger that has more amp output than your phone requires?
No.
With a phone that needs .75 A, is there a problem with using a charger that provides 2A?
No
Obviously getting less than the required amps takes longer to charge, but if your current is stronger than needed, does the phone only take what it needs?
Yes.
And if so, then what are all these "smart chargers" doing that a standard charger can't do?
Never heard of smart chargers.
But how does all this quick charge I keep hearing about factor in?
Factor in to what? They charge the phone quicker, simple as that.
 

tinpanalley

Golden Member
Jul 13, 2011
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Factor in to what? They charge the phone quicker, simple as that.
Does it matter how many amps they offer, does their circuitry in any way cause over heating problems with non-QC devices, do they require a certain type of USB cable, etc
 

Mike64

Platinum Member
Apr 22, 2011
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Never heard of smart chargers.
What Is a Smart Battery Charger?

Factor in to what? They charge the phone quicker, simple as that.
No, not really. [ETA: It's true that not all chargers charge all devices equally quickly, but that's more a case of an underpowered charger being slower than one of sufficient power to charge the device as fast as it's capable of being charged. But the true "Quick Charge" system works a bit differently and] the only "quick charge" (in those exact words versus, for example "fast charging") I'm familiar with is Qualcomm's proprietary "Quick Charge" system, which is basically a specific implementation of "smart charging" functionality. I've only seen it used in phones, but for all I know, it might be used in some tablets, too...
 
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Mike64

Platinum Member
Apr 22, 2011
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Does it matter [a] how many amps they offer, does their circuitry in any way cause over heating problems with non-QC devices, [c] do they require a certain type of USB cable, etc
[a] Yes [or I guess I should say I assume that any QC-capable charger supplies the necessary current to charge the QC-enabled devices it's designed for. Whether different versions are available with different wattage outputs, I'm not sure, but again, at the risk of making the proverbial ass of myself, I assume the answer to that is also "probably yes."]

If properly implemented, it shouldn't. They should just work like ordinary chargers if the attached device doesn't have QC circuitry itself.

[c] I'm not sure about that. I've read reviews/comments that some cables didn't work with Qualcomm QC, but that may be because the cables weren't actually manufactured true-to-spec rather than not being "special" cables...
 
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shabby

Diamond Member
Oct 9, 1999
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Does it matter how many amps they offer, does their circuitry in any way cause over heating problems with non-QC devices, do they require a certain type of USB cable, etc
The phone determines how many amps its going to pull from the charger not the other way around, so i can use a qc3.0 charger on a galaxy s1 and it'll work just fine.
With higher wattage chargers you normally want better quality cables, forget about the 99 cent ebay ones, they're too thin to pass 2-3amps. You'll see some cables marketed with 20-24 awg wiring, these are the cables you want for quick charge especially if you want a longer 6-10 foot cable. With 1-3 foot cables you might get away with lower quality cables.


No one calls their phone charger a smart charger, that's what i meant.
 

tinpanalley

Golden Member
Jul 13, 2011
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No one calls their phone charger a smart charger, that's what i meant.
Hence my use of quotes to suggest an idea rather than a trademarked name when I said...
...what are all these "smart chargers" doing...
 

Kelvrick

Lifer
Feb 14, 2001
18,422
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No one calls their phone charger a smart charger, that's what i meant.

I agree nobody calls their phone charger a smart charger, but some are labeled to be more intelligent than others. I believe what Anker calls PowerIQ and various other brands having smart or iq something or other is what the OP is referring to.

http://www.amazon.com/iClever-BoostCube-Technology-Blackberry-Bluetooth/dp/B00QTE09SY
http://www.amazon.com/Anker-Charger-PowerPort-Foldable-iPhone/dp/B012WMWPJW/

From the sounds of things, I don't think it does much, since the device is what "pulls" the current from the charger, depending on how much the charger can give.

I wish there were more "intelligence" for cutting off power to prevent overcharging or overheating.