Database Users

2A charger used with other phones

Hello!
Just curious if there is an issue with using my new Nexus 10 2A charger with other phones, such as my HTC Sensation or Blackberry Torch?
The Sensation uses a 1A charger, but I assume the phones are smart enough to only draw the current necessary, so they won't be damaged by drawing too much?
I'd like to just use the Nexus 10 charger and not have to carry other ones.

yes it is fine

Cool thanks

EniGmA1987 said:
yes it is fine
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I heard though that
*first it creates unnecessary heat because the current drawn by circuitry on lower amperage device has to be dissipated as heat
*second, this is less science/engineering but someone said that the specific pins are created by companies and the pins themselves can vary in terms of impedance, thus change the overall circuitry of the device in the long run
*third Li-Ion can pull more current than the default charger and it tends to do so to charge faster, albeit at the cost of the battery overall life deteriorates because higher charging rates also leads to faster breakdown of cells?
I wish I had sources, but this is what I pulled off the Internet when I was younger... can you please assist and advise? Would greatly appreciate (even if we start new thread from this

nutnub said:
I heard though that
*first it creates unnecessary heat because the current drawn by circuitry on lower amperage device has to be dissipated as heat
*second, this is less science/engineering but someone said that the specific pins are created by companies and the pins themselves can vary in terms of impedance, thus change the overall circuitry of the device in the long run
*third Li-Ion can pull more current than the default charger and it tends to do so to charge faster, albeit at the cost of the battery overall life deteriorates because higher charging rates also leads to faster breakdown of cells?
I wish I had sources, but this is what I pulled off the Internet when I was younger... can you please assist and advise? Would greatly appreciate (even if we start new thread from this
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Click to collapse
Wish I knew for sure too. REally I don't care a lot about my HTC Sensation as I plan on getting a Nexus 4 LTE when it eventually comes out. Hopefully those come with 2A chargers!
Sure I could get a Nexus 4 and use LTE right now on Bell, but I'd rather wait for an official one.

nutnub said:
I heard though that
*first it creates unnecessary heat because the current drawn by circuitry on lower amperage device has to be dissipated as heat
*second, this is less science/engineering but someone said that the specific pins are created by companies and the pins themselves can vary in terms of impedance, thus change the overall circuitry of the device in the long run
*third Li-Ion can pull more current than the default charger and it tends to do so to charge faster, albeit at the cost of the battery overall life deteriorates because higher charging rates also leads to faster breakdown of cells?
I wish I had sources, but this is what I pulled off the Internet when I was younger... can you please assist and advise? Would greatly appreciate (even if we start new thread from this
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Click to collapse
Everybody seems to misunderstand LiPo charging, as it is different than previous battery technologies
For general LiPo Information, you should look here. Charging information is about halfway down the page
http://www.rchelicopterfun.com/rc-lipo-batteries.html

Ill quote the important part:
Selecting the correct charge current is also critical when charging RC LiPo battery packs. The golden rule here use to be "never charge a LiPo or LiIon pack greater than 1 times its capacity (1C)."
For example a 2000 mAh pack, would be charged at a maximum charge current of 2000 mA or 2.0 amps. Never higher or the life of the pack would be greatly reduced. If you choose a charge rate significantly higher than the 1C value, the battery will heat up and could swell, vent, or catch fire.
Times are a changing...
Most LiPo experts now feel however you can safely charge at a 2C or even 3C rate on quality packs that have a discharge rating of at least 20C or more safely and low internal resistances, with little effect on the overall life expectancy of the pack as long as you have a good charger with a good balancing system. There are more and more LiPo packs showing up stating 2C and 3C charge rates, with even a couple manufactures indicating 5C rates. The day of the 10 minute charge is here (assuming you have a high power charger and power source capable of delivering that many watts and amps).
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Pretty much all phones are right around 2000mAh capacity now days so even going by the "old" golden charging rule a 2A charger would be safe to use. My Galaxy Nexus came with (I think) a 1A charger, but ever since I got my tablet shortly thereafter I have just used the tablets 2A charger for both devices and never once had an issue. It has been 8 months now of using the 2A charger on my phone. Idle life can still reach a little over 3 days on a single charge and I still get one of the best screen on time's of most people I know around the forums. So yes from personal experience a 2A tablet charger is completely fine to use on a phone.

Charging circuitry is built into the device, not the "charger"
Nothing to worry about

EniGmA1987 said:
Ill quote the important part:
Pretty much all phones are right around 2000mAh capacity now days so even going by the "old" golden charging rule a 2A charger would be safe to use. My Galaxy Nexus came with 9I think) a 1A charger, but ever since I got my tablet shortly thereafter I have just used the tablets 2A charger for both devices and never once had an issue. It has been 8 months now of using the 2A charger on my phone. Idle life can still reach a little over 3 days on a single charge and I still get one of the best screen on time's of most people I know around the forums. So yes from personal experience a 2A tablet charger is completely fine to use on a phone.
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Is it safe to assume that all chargers come default at 1C charging for their device? Because if that's the case, I figure most electronics we own can just be replaced with 10w chargers (which would make life much more convenient).
This is slightly related/unrelated, but how do you know whether a charger is "high quality" or will only provide "constant current / constant voltage"? It seems strange to me that these days, you can't find the circuitry of many devices we own publicly available so you can't check if the design is good (let alone how they chose the components in their design?). Do you (and other veterans) have any thoughts on this?
Thanks for teaching me lots!
-newb, happily reading away

I bought one of those 2amp double chargers from a seller on Amazon. It wasn't really cheap either (in cost anyway- I spent a bit more hoping it would be higher quality). After plugging in my MotoRAZR and the wife's lumia the charger popped and some plastic from the housing of the charger flew across the room! Thankfully both phones were fine.
I wondered whether both phones tried to pull more than the charger could handle and the charger had poor quality circuitry.
Since then, I've only ever bought branded official replacement chargers (Motorola, Samsung etc). I'd happily mix and match them to the phones but I'd be wary of buying a no name Chinese jobby from Ebay or Amazon marketplace.
Sent from my XT910 using xda premium

nutnub said:
Is it safe to assume that all chargers come default at 1C charging for their device? Because if that's the case, I figure most electronics we own can just be replaced with 10w chargers (which would make life much more convenient).
Click to expand...
Click to collapse
Most batteries can discharge a lot faster than they can recharge, but with LiPo, the difference is getting smaller.
Batteries used to need trickle charging as if you charge fast they would get hot, which causes the chemicals inside to expand(think like a fizzy drink, pour it fast and it will overflow) causing the battery to burst, exposing nasty chemicals.
New technology means the charger can accurately monitor how fast we fill the battery, without letting it get too hot, and also the way it is filled(as with the fizzy drink, pour down the side of a glass rather than straight to the bottom and you will fill the glass faster, with less chance of it over-spilling)
This is slightly related/unrelated, but how do you know whether a charger is "high quality" or will only provide "constant current / constant voltage"? It seems strange to me that these days, you can't find the circuitry of many devices we own publicly available so you can't check if the design is good (let alone how they chose the components in their design?). Do you (and other veterans) have any thoughts on this?
Click to expand...
Click to collapse
Unfortunately, industry is full of products made to a budget, usually by using cheaper components/designs(the charger for the ASUS TF101 was renowned for failing), so there is no foolproof way of determining 'quality' apart from word of mouth, looking at quantities sold, feedback in reviews/forums.
Basically, it boils down to 'consumer testing'
---------- Post added at 09:54 AM ---------- Previous post was at 09:38 AM ----------
Here's a bit more related information found buried deep in documents here: http://www.usb.org/developers/devclass_docs
The USB2.0 specifications for current output say the maximum current is limited to 1.8A, while USB3.0 has a maximum current limit of 5A
Hopefully, USB3.0 will quickly become a new standard for portable devices.

more questions!
First of all, let me please thank you for responding and being so thorough with your answers! There is so much information out there, and in my 22 years of existence, I cannot for the life of me sort through the sheer amount of data. I do greatly enjoy reading every little thing that is posted, especially in this thread because I think it's super important to understand the electronics that we interact with.
sonicfishcake said:
I bought one of those 2amp double chargers from a seller on Amazon. It wasn't really cheap either (in cost anyway- I spent a bit more hoping it would be higher quality). After plugging in my MotoRAZR and the wife's lumia the charger popped and some plastic from the housing of the charger flew across the room! Thankfully both phones were fine.
I wondered whether both phones tried to pull more than the charger could handle and the charger had poor quality circuitry.
Since then, I've only ever bought branded official replacement chargers (Motorola, Samsung etc). I'd happily mix and match them to the phones but I'd be wary of buying a no name Chinese jobby from Ebay or Amazon marketplace.
Sent from my XT910 using xda premium
Click to expand...
Click to collapse
My concern with this is that if Motorola or Samsung does put out a product less than optimal, would we all know? Another way of asking this is how do we know that Apple/Motorola/Samsung/Lenovo does produce superior products and it's not merely a matter of advertisement or brand image? Do you think there is a way to know, as a consumer, that even third party products are becoming more competitive, given that smaller companies have much harder time advertising and building a name/brand for themselves? (if you can't tell, I am rooting for the little guys because I may one day work for the little guys)
skally said:
Most batteries can discharge a lot faster than they can recharge, but with LiPo, the difference is getting smaller.
Batteries used to need trickle charging as if you charge fast they would get hot, which causes the chemicals inside to expand(think like a fizzy drink, pour it fast and it will overflow) causing the battery to burst, exposing nasty chemicals.
New technology means the charger can accurately monitor how fast we fill the battery, without letting it get too hot, and also the way it is filled(as with the fizzy drink, pour down the side of a glass rather than straight to the bottom and you will fill the glass faster, with less chance of it over-spilling)
Click to expand...
Click to collapse
Thank you for clarifying for us. Would you happen to know if there are specifics to recharge specs, short of finding me published papers on the technology? What you said is definitely what I've been reading from the Internet and I do trust you, just would help me have greater peace of mind with my nice and shiny devices,,,
skally said:
...
Unfortunately, industry is full of products made to a budget, usually by using cheaper components/designs(the charger for the ASUS TF101 was renowned for failing), so there is no foolproof way of determining 'quality' apart from word of mouth, looking at quantities sold, feedback in reviews/forums.
Basically, it boils down to 'consumer testing'
---------- Post added at 09:54 AM ---------- Previous post was at 09:38 AM ----------
Here's a bit more related information found buried deep in documents here: http://www.usb.org/developers/devclass_docs
The USB2.0 specifications for current output say the maximum current is limited to 1.8A, while USB3.0 has a maximum current limit of 5A
Hopefully, USB3.0 will quickly become a new standard for portable devices.
Click to expand...
Click to collapse
A quick question, just because USB3.0 should allow up to 25W, that doesn't mean that it's the standard for devices, does it? As in Nexus 10 probably can only draw 10W, even if my computer (which although stated is USB3.0) may not have the circuitry behind it to allow for such a draw? I'm a little iffy on the whole implementation of USB standards. Because if USB2.0 has draw of up to 9W, I haven't seen this from my laptop or any devices claiming to have USB2.0 ports,,,
but then again, I may be paranoid. Just trying to line up my experience with theory!
Thank you all for so much support and enthusiasm. Any chance we'll see this on a top thread somewhere?

nutnub said:
A quick question, just because USB3.0 should allow up to 25W, that doesn't mean that it's the standard for devices, does it? As in Nexus 10 probably can only draw 10W, even if my computer (which although stated is USB3.0) may not have the circuitry behind it to allow for such a draw? I'm a little iffy on the whole implementation of USB standards. Because if USB2.0 has draw of up to 9W, I haven't seen this from my laptop or any devices claiming to have USB2.0 ports,,,
but then again, I may be paranoid. Just trying to line up my experience with theory!
Thank you all for so much support and enthusiasm. Any chance we'll see this on a top thread somewhere?
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Click to collapse
If the Nexus kernel says the limit is 2A then that's it. It cant use more power.
Have you seen the internal USB 3.0 cable?
It's at least twice as thick as a USB 2.0 cable, I got a new chassi for my computer last week, with a couple 2.0 and a 3.0 USB front port.
And if your motherboard's built for USB 3.0, I'm pretty sure it can take the current. Otherwise there would be no meaning of adding 3.0 support.
Sent from my Nexus 10 using xda app-developers app

If something is listed as a USB3 port, it must be up to USB3 certifications. Otherwise the manufacturer of the device is liable for a huge lawsuit if issues arise. If something says USB3 that doesnt mean it IS drawing 25w though, just that the port is capable of having 25w pulled through it over the USB connector. Same with USB2 and its 9w limit on the spec. Also, plugging a tablet such as this into a computer's USB3 port does not mean it will charge faster or get faster data transfers, since the cable being used and the device are still of the older specification.

nutnub said:
Thank you for clarifying for us. Would you happen to know if there are specifics to recharge specs, short of finding me published papers on the technology? What you said is definitely what I've been reading from the Internet and I do trust you, just would help me have greater peace of mind with my nice and shiny devices,,,
Click to expand...
Click to collapse
Have a look here for info on the recharging process for Lithium based cells.
https://sites.google.com/site/tjinguytech/charging-how-tos/the-charging-process
It is worth noting the level of precautions taken while charging the cells aggressively. You really don't need a bucket of sand on standby when you plug your phone in to it's charger
nutnub said:
A quick question, just because USB3.0 should allow up to 25W, that doesn't mean that it's the standard for devices, does it? As in Nexus 10 probably can only draw 10W, even if my computer (which although stated is USB3.0) may not have the circuitry behind it to allow for such a draw? I'm a little iffy on the whole implementation of USB standards. Because if USB2.0 has draw of up to 9W, I haven't seen this from my laptop or any devices claiming to have USB2.0 ports,,,
Click to expand...
Click to collapse
There are actually 2 different current limits for each USB specification: USB2.0 has 0.5A and 1.8A, while USB3.0 has 1.5A and 5.0A
The lower of the current limits is what I would expect to get from a USB port on a computer, while the higher one I would expect to get from a dedicated charger.
I believe the higher current specification was added purely for charging mobile devices, as it is only achieved by adding a resistance across D+ and D-, removing the data transmission capabilities of the port. I don't know if that's practical, or possible with a computer USB port.
I do remember seeing motherboards with ports specifically designed for fast charging, but I haven't got any info on them as yet.

There are also kernels which enable "fast charging" on a PC. Basically it removes the data connection in software and treats any USB connection as if it were plugged into AC. You can charge just as fast on a computer as you can on a wall charger when this feature is enabled in the kernel.

I am using the N10 charger for my Note 2 and it charges bloody fast using this charger. Charging is noticeably faster on Note 2 than the stock 1A charger that came with the Note.
Battery is not getting warm and battery temps are similar to those on 1A charger. Basically its cutting the charging time in almost half.

Agreed. Note 2 charger is awesome. Bought a powergen 3.1 amp car charger for the note 2 also after watching videos and reading up on proper car chargers for the phone. Guess I can use it for my nexus 10 too.
Sent from my Nexus 10 using xda premium

I own RC cars with lipo batteries and rule of thumb is total mah divide by 1000 = the Max amp charger you can use. So a 2100mah battery can be charged with a 2.1A charger.
On that note I charge my Samsung s3 that has a 2100mah battery with a 2.1A car charger without any issue.
Sent from my SGH-T999 using Tapatalk 2

I used the N10's charger to charge my iPod Nano 3rd gen, no problem

What's the big deal with wireless charging?

Warning: When I make this post, I have no intention of being rude. Moving on.
Lately I've seen lots of posts like, "Wireless charger, cheap on Amazon!" and "Wireless charger, 40$!" Ok, thanks for finding these things for us! But is wireless charging practical? Why is wireless charging being made such a big deal? Persononaly, I cant justify avoiding the phones intended function, just to charge wirelessly. Not to mention, I have to pay 40+$ for said wireless charger. I mean really, is it that important to "preserve the USB port"? On the other hand, I do think wireless charging is a neat idea, but only that.
So I guess my question is, are there reasons that make this worth my money? What are they?
Sent from my Nexus 4 using Tapatalk 2

Laziness and neatness for me. It's less work to place it on a wireless charger than to have to find the usb cable and plug it in. Plus it eliminates the eyesore of having an unplugged USB cable right next to my bed all day.

It's great that Google included it for those who have a use for it but I have to say I'm with the OP. It just doesn't make much sense to me to have to buy an expensive device that takes up space to save a few seconds spent plugging the device in once a day. Different strokes for different folks, eh. Plus I'd have constant paranoia about whether the device was actually going to keep charging while I sleep (irrational, I know. Nobody said I had to make sense.) That's why we love Android (or not, for the trolls lol)

nbell13 said:
Laziness and neatness for me. It's less work to place it on a wireless charger than to have to find the usb cable and plug it in. Plus it eliminates the eyesore of having an unplugged USB cable right next to my bed all day.
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Yeah, I guess that's reasonable... But is it really worth 40+$ to save yourself a few seconds everyday?
Sent from my Nexus 4 using Tapatalk 2

Alot of Nexus 4 users upgraded from the Gnex. The Gnex had a horrible USB port. If you go to the Gnex Q&A section and search for bad USB port you will get easily over 100 threads. And although the Nexus 4 is obviously a different manufacturer, it was enough to make us paranoid. Add the paranoia to the fact that wireless charging is just cool new technology definitely makes it worth $50 TO SOME people.

I like cables. Seriously. Cheap and reliable. But that's just me.

I think the idea of them is great, but they just aren't for everyone. I'd love one, for the visuals but in all honesty, I have no reason to own one. For one, I don't even have a good surface I could put it on, most of them have something on or are not near a plug socket.

The wireless charging orb from Google advertises charging the Nexus4 in 4 hours.
In my experience the wall charger does it in about 2 hours.
I've been using my Nexus4 for navigation in my car. A car mount with wireless charging
indeed sounds great - plugging and unplugging the USB port in the car is uncomfortable.
But I discovered that with the GPS on and the screen at high brightness the phone
can not be properly charged with a 0.5A car lighter adapter. 2A ones do work.
So I wonder if a wireless charging car mount is even a possibility. It is questionable whether it
can pump the necessary power to run the phone in such a demanding application.
Mind you my setup can get pretty hot at times on the USB and it's the dead of winter in here.

[Q] Installed Wireless QI Chrager- how do I see exactly how fast it is charging?

I just installed a QI charger for my new LG G2. I got a few QI charging pads as well. I want to see how fast it is charging, or the charge rate (500mah, 750? ect) as the receiver is supposed to do the following charge: DC 5V/500mA-1000mA .
Ive tried a few apps, but I cant find one that specifically says what the charging rate is. Anyone know the best way to figure that out?

Two questions:
1) When you say you "installed a QI charger for my new LG G2" exactly what do you mean there, and I do mean exactly: are you referring to getting a Qi charging pad (which you mention) or do you mean you got some kind of part that you physically installed in or on your G2 - the Verizon G2 is the only one that supports wireless charging out-of-the-box so, that's why I'm asking.
2) With respect to actual charging, the output of the Qi wireless charging pad is directly related to the amperage/current supplied by the actual AC adapter or USB charger you're using with it. If it's about 1A (the AC or USB charger) then you're going to lose quite a bit of power in the actual charging process because wireless charging is pretty severely inefficient most of the time, give or take you'd get 400 to 500mAh going into the actual device from the charging pad.
What I'm saying is if you have a Qi wireless charging pad, you'd be best served using as high an amperage/current charger for the pad itself so that the pad can then transfer as much as possible to the device itself. Anything less than a solid 2A charger attached to the Qi wireless charging pad and you're basically wasting a lot of it in the process and might be better off actually just using the USB port on a computer or something (about 500-550mAh max anyway).
Basic rule of thumb: the Qi wireless charging pad can use all the amperage/current it can get, with at least the factory LG 1.8A charger being what I'd call the bare minimum (and with that you'd probably be able to push about 900 to 1000 mAh (aka 1A) to the device. Qi hardware is roughly 40% efficient so, you're going to lose a lot in the process as stated; the more you start with the more that gets to the device even accounting for the inefficiency.
As far as measuring the current, you can try CurrentWidget on the Play Market, it may provide you with some info in terms of the charging rate.

br0adband said:
Two questions:
1) When you say you "installed a QI charger for my new LG G2" exactly what do you mean there, and I do mean exactly: are you referring to getting a Qi charging pad (which you mention) or do you mean you got some kind of part that you physically installed in or on your G2 - the Verizon G2 is the only one that supports wireless charging out-of-the-box so, that's why I'm asking.
2) With respect to actual charging, the output of the Qi wireless charging pad is directly related to the amperage/current supplied by the actual AC adapter or USB charger you're using with it. If it's about 1A (the AC or USB charger) then you're going to lose quite a bit of power in the actual charging process because wireless charging is pretty severely inefficient most of the time, give or take you'd get 400 to 500mAh going into the actual device from the charging pad.
What I'm saying is if you have a Qi wireless charging pad, you'd be best served using as high an amperage/current charger for the pad itself so that the pad can then transfer as much as possible to the device itself. Anything less than a solid 2A charger attached to the Qi wireless charging pad and you're basically wasting a lot of it in the process and might be better off actually just using the USB port on a computer or something (about 500-550mAh max anyway).
Basic rule of thumb: the Qi wireless charging pad can use all the amperage/current it can get, with at least the factory LG 1.8A charger being what I'd call the bare minimum (and with that you'd probably be able to push about 900 to 1000 mAh (aka 1A) to the device. Qi hardware is roughly 40% efficient so, you're going to lose a lot in the process as stated; the more you start with the more that gets to the device even accounting for the inefficiency.
As far as measuring the current, you can try CurrentWidget on the Play Market, it may provide you with some info in terms of the charging rate.
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Click to collapse
Firstly, thank you for taking time to write such a great response. I really appreciate it!
1) Yes I installed a universal sticker. I used this one http://www.amazon.com/gp/product/B00MN3RR7Q/ which is supposedly supposed to do 1000mA. People in the reviews seem to say they are getting good results. I wish the ATT version had wireless out of the box, but then if it did I would be stuck with PMA charging. I installed an actual NFC/PMA sticker in my G3. PMA kind of sucks...anywho.
2) This is the pad I am using: http://www.amazon.com/gp/product/B00H9B7ALK/. 1.5a input and 1a output. On this one, I am averaging about 3% per 10 minutes or 30% an hour. So roughly 3 hours and 20 minutes to full charge. I can try the the stock LG. Oh, my Dell Venue 8 Pro is a 2a one. I can try that as well. Can the paid take the 2a in even though it was built for 1.5a in?
I will try current widget. Ive been using battery monitor to log as well.

1) Neat, I didn't even know such a thing existed, I may have to give that a shot with my G2 at some point (if I decide to keep it, that is).
2) As stated before, using a higher amperage/current charger or power supply is preferred, sure. It should help get the charging done faster and again the device (meaning the charger) will pull what it requires and nothing more.
Basic electronics 101 here: two things that matter with respect to smartphone chargers (or most any device, to be honest) - amperage aka current and voltage.
Voltage is pushed from a power supply meaning it will always be the same amount, give or take micro-variations. If it's a 5VDC power supply (of any kind) it's designed to provide 5VDC constantly. If it's some other value, say 9VDC, 12VDC, and so on, that's how much it pushes - if you were to connect a 9VDC charger to a smartphone or other device that's designed for a 5VDC input, you'd fry the electrical circuits in the device because it would be flooded with more power than it's designed for.
Amperage aka current is pulled from a power supply and only what is required is what's actually taken. With respect to smartphones, most of the higher end devices these days can make use of roughly 1.2 to 1.8 A (read as Amps) when it comes to charging. This means if you had a charger that output 5VDC (from what I just said above that's the standard worldwide for such devices as smartphones) but could theoretically provide 5A of current, the smartphone technically would not be damaged because it would only pull roughly 1 to 1.8 Amps at most - if you do use CurrentWidget and you plug in the G2 and look at the reading while it's charging, you'll note that the level of amperage/current being pulled from the charger fluctuates like crazy - voltage stays constant (give or take a microvolt here and there) but the current will jump all over the place, especially if you enable the "Smart Charging" feature of the G2.
The reason this happens is because when a LiIon battery is pretty low on a charge, say down to 10-15%, it's "gone deep" as the saying goes and the charging circuit will pull the max amperage/current that the charger is capable of producing and that can be measured/seen using CurrentWidget. As the battery gets into the 90% full range, the amperage/current draw will reduce (again, especially with the Smart Charging enabled) as the battery gets towards being totally full. This is a good thing in most every respect and it keeps the LiIon battery in good shape too - if it pulled the max current till it was 100% it wouldn't necessarily be so good and would heat the battery up more than necessary and LiIon batteries are very sensitive to temperature variations.
Hence, phones get fried by "cheap Chinese chargers" a lot of times because of voltage issues and faulty voltage regulators, not from amperage/current problems. It's actually kind of difficult to kill a device with amperage/current, but screwing around with the voltage will destroy a device almost 100% of the time and quite fast too.
Also, this is the reason why you'll see a phone charge relatively quickly to the 99% point then it seems to take even longer to get that last 1% to finish it off at 100% - it's the way LiIon charging technology works and helps the battery lifespan (meaning how long the battery is useful for measured in years and not "battery life" in terms of how long it can run before you have to charge it again measured in hours). The charging process "slows down" as it gets close to being full which works great for this kind of technology.
Hope this info helps...

br0adband said:
Basic rule of thumb: the Qi wireless charging pad can use all the amperage/current it can get, with at least the factory LG 1.8A charger being what I'd call the bare minimum (and with that you'd probably be able to push about 900 to 1000 mAh (aka 1A) to the device. Qi hardware is roughly 40% efficient so, you're going to lose a lot in the process as stated; the more you start with the more that gets to the device even accounting for the inefficiency.
Click to expand...
Click to collapse
Okay let me see if I understand this correctly. The OUTPUT of the qi charging pad could be 1000mAh, but since the wireless QI hardware is only 40% efficient, the actual charge rate will be more around mAh to 500mAh? Im recording an actual charge rate of 500mAh and my phone states it is on AC power and not USB.
If the receiver on the phone states it can do up to 1000mAh, what I need to find is a charger that outputs a lot more like 2000mAh and at 40% efficiency I might be able to get around the 1000mAh?

That pretty much sums it up, yep - as long as you account for the inefficiency of the Qi charging technology, you can get faster charge times and still use it without having to plug in/unplug, etc the old fashioned way.
It works, it's just not nearly as fast or efficient as the old fashioned way so, give the Qi pad plenty of current and you'll be fine - since it will pull what it needs, using a 1.8A or 2A or even more won't hurt it, but it will make it pretty damned warm to the touch when it's charging so keep that in mind. As the G2 would be sitting on top of the Qi pad, if the pad gets warm or even hot then obviously the G2 will as well by heat transfer and heat/high temps are bad for LiIon batteries as I mentioned earlier.
It's a trade-off more than anything else but again, it does work as long as you're understanding the hows and whys to make the best of it.

br0adband said:
That pretty much sums it up, yep - as long as you account for the inefficiency of the Qi charging technology, you can get faster charge times and still use it without having to plug in/unplug, etc the old fashioned way.
It works, it's just not nearly as fast or efficient as the old fashioned way so, give the Qi pad plenty of current and you'll be fine - since it will pull what it needs, using a 1.8A or 2A or even more won't hurt it, but it will make it pretty damned warm to the touch when it's charging so keep that in mind. As the G2 would be sitting on top of the Qi pad, if the pad gets warm or even hot then obviously the G2 will as well by heat transfer and heat/high temps are bad for LiIon batteries as I mentioned earlier.
It's a trade-off more than anything else but again, it does work as long as you're understanding the hows and whys to make the best of it.
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I ran the battery down to 70% and I have it on the charger with a 2a wall adapter. I will see how fast it charges. But it seems like I will get roughly 1/3rd the charging speed of a wall adapter. Which means in the car using gps with the screen on and QI chrarging will probably mean a negative overall power situation.
Im also going to try a high speed, charging only cable like this http://www.amazon.com/gp/product/B009W34X5O/ between the wall adapter and the charging pad to see if there is any difference.

Don't waste your money, that thing is no better than a "Gold Plated 56K Modem Cord," seriously. Gold plating, "high speed," all that stuff is marketing BS and means absolutely nothing in the long run - it's a microUSB cable, nothing more.
In 20+ years of using USB cords of all kinds I've yet to see one that's corroded so, that gold plating is not gonna matter anyway.
Any microUSB cable you can find today is more than capable of handling ~2A without a single issue and it's well known that the G2 can max out at 1.6A draw for charging anyway so any cable is more than adequate for doing it.

br0adband said:
Don't waste your money, that thing is no better than a "Gold Plated 56K Modem Cord," seriously. Gold plating, "high speed," all that stuff is marketing BS and means absolutely nothing in the long run - it's a microUSB cable, nothing more.
In 20+ years of using USB cords of all kinds I've yet to see one that's corroded so, that gold plating is not gonna matter anyway.
Any microUSB cable you can find today is more than capable of handling ~2A without a single issue and it's well known that the G2 can max out at 1.6A draw for charging anyway so any cable is more than adequate for doing it.
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Hah! I already have one I use in the car

shaxs said:
I ran the battery down to 70% and I have it on the charger with a 2a wall adapter. I will see how fast it charges. But it seems like I will get roughly 1/3rd the charging speed of a wall adapter. Which means in the car using gps with the screen on and QI chrarging will probably mean a negative overall power situation.
Im also going to try a high speed, charging only cable like this http://www.amazon.com/gp/product/B009W34X5O/ between the wall adapter and the charging pad to see if there is any difference.
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Okay I was able to maintain neutral power with the screen on and running gps. Let it go for almost 2 hours and it was at the same percentage as when I started. Im good with that for car use.

Does G2 accept Quick Charge 1.0/2.0?

The G2 seems to be capable of using Quick Charge 2.0, which is part of the Snapdragon 801 chipset. But with mine I got a basic AC wall charger, and if you read the (literally) microscopic text on it, it says it's putting out only 1.1 amps... which is well short of the at least 2 to 5 amps of many other chargers. So my questions are this:
1. Did anyone else get a higher capacity charger with their retail kit? Mine is a long rectangle bearing the LG logo.
2. If not, is this stock charger really not compatible with Quick Charge 2.0, or am I just reading the fine print wrong?

I've been researching this further, and it may be that LG intentionally shipped a low amperage charger. Because the battery is not user-serviceable, it would behoove them to use a slower charger, since ultra-fast charging harmful to the its life and capacity. The intricacies of rechargeable batteries are many, but the excess heat generated during charging degrades a Li-Ion pack pretty quickly, among other things.
Still, based on the assumption that the stock charger is truly 1.1A, I just bought a QC2 charger -- when I'm out in the field, I don't have time to sit and wait for something to charge at an outlet. I also bought a 10000mAh external battery with a solar panel. The rate at which LP eats juice is no joke.

@voxluna the g2 is using an Snapdragon 800 chipset and it might be capable of doing it but I don't know about it. But the micro usb port also doesn't support it as the additional pins were highlikely for slimport. Also using quickcharge on a device like this is highly risky as the device might not handle it too well. If the stock drains too much I suggest to find the cause of the problem and kill it or use an good custom rom with an good kernel and remove apps you aren't using. Goodluck.
Verstuurd vanaf mijn LG-D802 met Tapatalk

wulsic said:
@voxluna the g2 is using an Snapdragon 800 chipset and it might be capable of doing it but I don't know about it. But the micro usb port also doesn't support it as the additional pins were highlikely for slimport. Also using quickcharge on a device like this is highly risky as the device might not handle it too well. If the stock drains too much I suggest to find the cause of the problem and kill it or use an good custom rom with an good kernel and remove apps you aren't using. Goodluck.
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I will dig into the QC2 wiring plan, just out of curiosity. I am confused as to whether an extra USB 3.0 port/pins are necessary (like on the Note 3) or not. Though I believe that plugging a phone into a higher amperage device is not supposed to be harmful. It's too late to cancel the Amazon order, so we'll see.
What I don't know is if my 1.1A charger is what's standard with a retail G2. The reason I asked if anyone else got a different charger is that this phone was a refurb I got from T-Mobile. For example, it came with a cable that I don't think is OEM LG, because it doesn't work with ADB. OTOH, it is possible they just don't implement QC2, like most models don't have the FM radio capability. But, the radio is omitted because carriers don't want it competing with music downloads; as for faster charging, I can't think of a good reason you wouldn't offer that feature.

@wulsic After a little digging, it appears you don't need any extra pins like on the Note 3; a sync+charge cable will suffice. And that makes sense, because the QC2 standard applies all the way from Snapdragon 200s to 8xx. Nonetheless, so far I haven't seen any documentation saying the G2 compatible with 2.0 -- the single LG device listed by Qualcomm is a G4. Crazy, really.
That still leaves QC 1.0, but I have yet find anything that shows the G2 (however, Qualcomm's listing is dated from before the phone came out, so it's not definitive). It may also be that a plain 2A charger, which I do have, can do the job faster than this LG 1.1A. I'll have to do some accurate testing to quantify a difference.

Further research: I came across this thread, a post in which seems to indicate that the G2 can do fast charging. However, I'm having a problem with the current not showing up properly in monitoring apps, which is confounding this entire process.

[Comparison] Updated Charging Speeds Comparison (QC 2.0/3.0, 10W Qi, Standard) S7/S7E

Method:
First I used my phone until the battery was below 15% in order to get a better picture of what the charging would look like over almost a full battery cycle. I did not start at the same battery percentage for each test because I did not find any benefit to doing so. I original did this for uniformity, but it did not make a difference after trying it using the more accurate equipment.
I then cleared my history in the Battery Monitor Pro Widget (BMW Pro) recording app which was used to log the battery [mV], battery temperature [F], time, and battery percentage changes. Once this was done I plugged in my USB Power Monitor, turned airplane mode on, removed the case, and let the phone charge. I started logging the data via my power monitor once the phone showed it was charging. From this point onward I let the phone charge without interrupting it until it reached 100%, then I let it charge for another 10-60 minutes to see if it was still drawing power from each charger. Once all of this was done, I exported my data collected from BMW Pro, emailed it to myself, and pasted it along with the USB Power Monitor data into an Excel spreadsheet. All of the data was then delimited to separate the clusters of data due to the way they were recorded, and subsequently graphed. The USB Power Monitor recorded data points every 0.36 seconds, while the BMW Pro took recordings every 5 seconds because I was having issues with the “real-time” recording option in the app working correctly.
All of the data was then graphed into the nice figures you will see below; each color reflects the same variable across all of the graphs to make reading them easier. I included a legend at the top of each set of graphs which should also help make it easier to read the data.
The most interesting part of this test is how cool the S7 Edge stays while charging, and the very marginal difference in overall charging time between QC 2.0/1.0. A 15-minute gap is marginal at best given the ‘big improvements’ Qualcomm claimed when launching the newer standards.
When conducting the wireless charging tests I think there is some error in the Samsung Fast Wireless charging data, so I plan on redoing it at some point. I already redid the Choetech one because it has a similar strangely long, but now it seems more in line with what I initially found before using the newer testing equipment.
I wanted to also quickly point out that both my HTC 10 and S7 Edge keep pulling current even after the phones show they are 100% charged. I’m not talking about a tiny amount; they both pulled ~1-5W+ after hitting 100% battery which is A LOT considering they are reporting to be fully charged. I verified this using 3 multimeters just to be sure. It appears as if Qualcomm, or the OEM’s are falsely reporting when the phone is actually charged, or there’s some other shady things going on here.
Another thing I wanted to mention is how the S7 Edge is so consistent in the way it charges the battery. It could be due to the lower rates Samsung uses (9V/1.67A max which is 15.03W) vs the HTC 10’s up to 18W that I’ve seen it pull. Just take a look at how the S7 Edge charges using QC 2.0 compared to the HTC 10 with lower temperatures, similar times, and a much more consistent overall charging curve.
If you look at the Tronsmart & Choetech QC2.0 tests, then you might notice the large difference between the two. The Tronsmart charger has a harder time holding onto the proper voltages, therefore it bounces around more from ~8.92V-9.03V (a 0.11V change) while the Choetech one ranges from 9.077V-9.092 which is a significantly smaller 0.015V range. The power control chip is responsible for controlling these voltages, and clearly the Choetech one has a better chip in it. This is especially important for external battery packs where efficiency really matters due to the limited amount of power they can store.
Equipment:
These tests were conducted using a series of different chargers. The same brand was used for both Quick Charge 2.0/3.0 tests to minimize experimental error; This trend remained the same was also done for the wireless charging tests
Wall Chargers:
Quick Charge 2.0: Tronsmart 18W charger 5V/2A, 9V/2A, 12V/1.5A
Quick Charge 3.0: Tronsmart 18W charger 3.6-6.5V/3A, 6.5-9V/2A, 9-12V/1.5A
USB inline Power Monitor:
XYZ Studio 0-24V, 0-3A USB Power Monitor
Tronsmart 5-12V USB multimeter (not used in this test, but was used in the older version)
Software/App(s):
Battery Monitor Widget Pro
Excel
Notepad++
Realterm (for the USB power monitor logging)
Legend
QC 2.0 Tronsmart S7
QC 2.0 Choetech
QC 1.0 Samsung
Choetech Fast Wireless Charger
Samsung Fast Wireless Charger
Samsung Wireless Charger
Normalized data Table
Full sized downloadable pictures of everything (data wise) you see above.

very good stuff!
maybe you could also record the heat at the hottest spot of the phone during charging? I think qc3 has the same charge rate but its able to change voltage to reduce creating waste heat compared to qc2.0.
my main concern with the s7 is the battery life, i know it won't last me a full 18hr day so i really need a portable fast qc2 charger that is pocketable, so maybe 5000mah, but have not seen such a small qc charger tho

Excellent post and well-made graphs. Thanks for your efforts.

well done. good info here.

sonhy said:
very good stuff!
maybe you could also record the heat at the hottest spot of the phone during charging? I think qc3 has the same charge rate but its able to change voltage to reduce creating waste heat compared to qc2.0.
my main concern with the s7 is the battery life, i know it won't last me a full 18hr day so i really need a portable fast qc2 charger that is pocketable, so maybe 5000mah, but have not seen such a small qc charger tho
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I don't have a thermal camera, or way to do that otherwise I gladly would. I can recommend a small 6000mah external battery pack if you want; Ill do a quick write up too (if you need one). The Samsung charger stayed at 9V the whole time per my multimeter's reading it just dropped go .5A near the end.
CLARiiON said:
Excellent post and well-made graphs. Thanks for your efforts.
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ISperfection said:
well done. good info here.
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Thank you, I will add in a standard wireless charger test (since my free Samsung one is enroute), and I can also get their fast charger too. I believe Samsung's fast wireless charger is only 7W so it would be slower than the Choetech one but it never hurts to see how fast it is.
Sent from my Nexus 6P using XDA Labs

@Pilz yes pls let me know of a qc2.0 small portable charger I think a quick 30mins charge to add 50% battery life mid day will be the best ease-of-use solution for me.
with the heat measurement, I'll be happy with your commercial grade temperature sensor that the great designer created for you, your fingers or better yet, the inside of your wrist.
preferably touching the same area on the phone every time and grading something like 1-5 hot/comfort levels maybe? just suggesting, no pressure

sonhy said:
@Pilz yes pls let me know of a qc2.0 small portable charger I think a quick 30mins charge to add 50% battery life mid day will be the best ease-of-use solution for me.
with the heat measurement, I'll be happy with your commercial grade temperature sensor that the great designer created for you, your fingers or better yet, the inside of your wrist.
preferably touching the same area on the phone every time and grading something like 1-5 hot/comfort levels maybe? just suggesting, no pressure
Click to expand...
Click to collapse
I'll look into some methods to measure the heat easily while they're charging. I'm conducting the standard wireless charger test using my free Samsung wireless charger right now QC 2.0 chargers the fastest when you start at a very low battery percentage, so ideally you can achieve the results posted, but ambient temperature, starting % etc contribute to whether or not that's attainable. It's still a good estimate for 30 minutes of charging +/- 5% for other factors. The phone also chargers slower when the screen is in. The rate would go from 9V/1.67A to 9V/1.10A with the screen on. It was very consistent when I turned the screen on and off during the test.
Sent from my Nexus 6P using XDA Labs

i actually won't care about heat issues while charging this time round, it'll be like my moto defy, i just run it under cold water after a fast hot charge, wont be using the s7 for many years so not worried about moisture build up.
i have ordered a magnet micro usb cable that says its rated for 2.4A charging so hopefully it'll allow easy qc2.0 charging, no need to plug in, it magnetically snaps on and off.
i think the best charge setup would be a 30mins quick charge (magnet) on the office desk than a 60mins wireless qi charge, carried in your pocket type situation.

sonhy said:
i actually won't care about heat issues while charging this time round, it'll be like my moto defy, i just run it under cold water after a fast hot charge, wont be using the s7 for many years so not worried about moisture build up.
i have ordered a magnet micro usb cable that says its rated for 2.4A charging so hopefully it'll allow easy qc2.0 charging, no need to plug in, it magnetically snaps on and off.
i think the best charge setup would be a 30mins quick charge (magnet) on the office desk than a 60mins wireless qi charge, carried in your pocket type situation.
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Did you by chance order the Znaps? I backed them ages ago for both the Type-C and micro USB connectors. If I'm lucky I might eventually maybe sometime before I die receive them. I don't expect much from a kickstarter campaign that's been delayed this much. I'm finishing up the standard Qi/PMA charging test. It shouldn't matter the standard it's using but if it's important the Samsung wireless charger is actually PMA.
Sent from my Nexus 6P using XDA Labs

OP Updated
-Standard wireless charging test added
-All figures updated to reflect the new test

no, its from aliexpress, $10 or so, ive seen cheaper so I would say the poor Kickstarters had their designs stolen and made cheaper... im not sure, i just buy what's available and easy. just search magnet usb cable, you'll find heaps, the more exy ones claim 2.4A current rating.

sonhy said:
no, its from aliexpress, $10 or so, ive seen cheaper so I would say the poor Kickstarters had their designs stolen and made cheaper... im not sure, i just buy what's available and easy. just search magnet usb cable, you'll find heaps, the more exy ones claim 2.4A current rating.
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Let me know how it works, I rarely use cables to charge my phone becusse I hate micro USB ports plus I'm used to the type C on Nexus.
Sent from my Nexus 6P using XDA Labs

Have you tried charging with 18w charger(not wireless) rather than the samsung one?

peachpuff said:
Have you tried charging with 18w charger(not wireless) rather than the samsung one?
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Yes it doesn't matter becuase the phone is only rated for 15.03W so it can't use more than that no matter the charging method. See screenshot below:
Sent from my Nexus 6P using XDA Labs

@Pilz yeah sure, it should arrive in a couple of weeks. i hate plugging in as well, even with the usb type c, its reversible but finding the port isn't always easy, they should have made the port surface like a cone or funnel so your guided into the port more easily.
the use of the magnet is awesome, Sony's external side charging pins have been around for ages, its really the charging current and quality of the copper that im worried about.

sonhy said:
@Pilz yeah sure, it should arrive in a couple of weeks. i hate plugging in as well, even with the usb type c, its reversible but finding the port isn't always easy, they should have made the port surface like a cone or funnel so your guided into the port more easily.
the use of the magnet is awesome, Sony's external side charging pins have been around for ages, its really the charging current and quality of the copper that im worried about.
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I just wish they had Type-C because its so much better especially after using it for a while now.
Sent from my Nexus 6P using XDA Labs

I never knew that plugging in a micro USB cable was so difficult. It could be one of those things that once you try a better alternative (type c maybe?) makes you ask how you lived without it, but I don't see what the fuss is about just yet.
I've used wireless chargers for years (way back in the NExus 5 days even) including in the car. Any word on fast wireless charging and heat? I'm worried about it pumping a ton of heat on to the back of the phone especially for extended periods such as overnight.

xxaarraa said:
I never knew that plugging in a micro USB cable was so difficult. It could be one of those things that once you try a better alternative (type c maybe?) makes you ask how you lived without it, but I don't see what the fuss is about just yet.
I've used wireless chargers for years (way back in the NExus 5 days even) including in the car. Any word on fast wireless charging and heat? I'm worried about it pumping a ton of heat on to the back of the phone.
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Click to collapse
Micro USB is just more of a hassle becusse usually you need to angle it while inserting it into the phone. Type-C is nice becuase there no worrying about how I need to orient a cable when I'm half awake plugging my phone in. It's hard to understand why its nice until you use it everyday.
I haven't been able to measure the heat yet, but the phone is cooler using the 10W wireless fast charger than it is using QC 2.0. The phone isn't hot to the touch but it is warm using the fast wireless charger. I'll try to download a battery monitoring app that measures battery temp while it's charging. This method won't be as accurate as physically measuring it, but it should still give a good indication of the temperature.
Edit: I tested the temperature using GSAM battery montior via the fast wireless charger fro ~6% charge (28-34%) and the temperature rose 6 [F], the I let the phone cool and tested QC 2.0. The phone was charger for 6% to keep things cosnistent with a temperature change of 5[F]. I would need to find a way to more accurately measure these values because that quick test doesn't really mean anything at this point.
Sent from my Nexus 6P using XDA Labs

Does the Adaptive Fast charging by Samsung with with QC 2.0 compatible devices or is it only exclusive to Samsung?

ahrion said:
Does the Adaptive Fast charging by Samsung with with QC 2.0 compatible devices or is it only exclusive to Samsung?
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It's just a QC 2.0 charger from what I can tell. I have a battery pack that will charge using QC 2.0 so I can test it using my multimeter
Sent from my Nexus 6P using XDA Labs