Database Users

[FAQ] Nexus 7, Chargers, and You

An all-in-one answer to the various "Which charger do I use" threads floating around.
Disclaimer: This is not exhaustive. I bear no responsibility for any incorrect purchases, damage to property, and other losses sustained.
Question: "I have an iPad charger. Will this charge the Nexus 7?"
Answer: No. Apple uses proprietary signalling in the iPad charger. As a result, they will not charge our Android devices at any rate above 500mA. Also avoid third-party chargers that are "Made for iPad/iPod/iPhone" and the like - they will probably not charge at the full 10W, although high-end universal products will usually be compatible with both iPad and the Nexus 7.
Question: "I have a BlackBerry Playbook/Samsung Galaxy Tab/HP Touchpad charger. Will it charge the Nexus 7?"
Answer: Likely yes. Any 2A charger should do the job, as long as it isn't designed solely for iDevices.
Question: "I want to use the charger that came with my smartphone, is it safe to charge my Nexus 7 with that?"
Answer: Yes. Charging a high-current device with a lower-powered charger will not cause a dangerously high current to be drawn - a 1.2A charger will simply cap out at 1.2A when charging the Nexus 7.
Question: "I want to charge my both my phone and my Nexus 7 from a 2A charger, is it safe to do that?"
Answer: Yes. A charger does not "push" current into a device - the device requests a certain current, and the charger delivers it. The minuscule current requirement of a Bluetooth handsfree earpiece can be safely supplied by the 2A Nexus 7 charger.
Question: "What's the difference between the official charge cable and a third party cable?"
Answer: Very little, as long as the third-party cable is of decent quality. Other cables may or may not physically fit depending on physical dimensions due to the Nexus 7's curved edge, but all microUSB to USB cables should be electrically identical.
Question: "Do you have a list of chargers that will charge the Nexus 7?"
Answer: What you are after is a charger that has an output of approximately 2A or above, although a lower powered charger should charge the Nexus 7 (but take longer).
Chargers that will "Fast Charge" - i.e output ~10W (not exhaustive)
Official Charger
HP Touchpad charger
ASUS Transformer TF101 Charger (AD827M)
Kindle Fire Charger
Blackberry Playbook Charger
Most Sleep and Charge USB 3.0 ports on laptops and PCs (may vary by output)
High-end portable universal USB chargers with a 5V 2A output such as Trent iCarrier, Anker Astro series, Incredicharge I-11000, etc.

Please make this sticky... in the Accessories Foirum
MODS: Please consider making this a sticky in the Nexus 7 Accessories Forum. Much of the talk in this, this and other threads is answered by the OP. It's very well written and addresses much of the confusion on the issue.
Or at least consider some effort to merge these threads.
Thanks!

No offense to the OP of this thread, but there's no information about getting the tablet charging at the same rate on a third party 2A charger versus the stock charger. There's a difference between having a charger "work" and having a charger work like the stock charger. I have another thread going regarding charging and you might find these two posts helpful.
http://forum.xda-developers.com/showpost.php?p=29049082&postcount=7
http://forum.xda-developers.com/showpost.php?p=29641898&postcount=40
This answer from the OP looks suspiciously like what I wrote in my first post.
Answer: Yes. A charger does not "push" current into a device - the device requests a certain current, and the charger delivers it.
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Might just be a coincidence though.

AZImmortal said:
No offense to the OP of this thread, but there's no information about getting the tablet charging at the same rate on a third party 2A charger versus the stock charger.
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I think you may have just helped add some (answered) questions to the FAQ
Here is a question I think might be useful to include:
"How can I know at what my rate N7 is being charged?"
(The answer would include the techniques and/or apps that would help one know whether their charger is operating at maximum, or if not, how much less)
I'm also curious to know whether an adaptor such as this one could be used to convert an iPad charger to work with an N7
Yes, there are many threads on the issue scattered around, and I'm more interested in having them most usable than being concerned about who wrote what first. A FAQ format would work best as a sticky, and could be populated by much of the existing information AZimmortal and others have provided. Another thread has a decent listing of "what chargers work" that goes beond the OP here, and could easily be merged in
Best case scenario is for the OP to incorporate material from other threads -- giving credit where approrpriate -- keeping to the FAQ format.

That adapter you linked is more or less like the one I have. I used to own a Galaxy Tab and sold it the day after I got my Nexus 7. In hindsight, I should've tested the charger to see if it would charge at the same rate. If you end up buying such an adapter and can test out charging with another 2A charger, then I'd love to see the results. Unfortunately, I don't have another 2A charger to test with.

It would be nice to have an app that gives us a clue about what's going on when we plug into a charger.
Maybe it could display the request the Nexus 7 made for power, what the response was, how much power is being sent, expected recharge completion time, etc.
Does such an app exist? Would it be difficult to create one?

Has anybody used the PortaPow Quad 4 Port USB charger with the Nexus 7 yet, and if so what were the results?
I've bought a couple of supposedly 2A multi USB chargers and they don't seem to want to play with my Nexus. Don't particularly want to buy every one on the market to test them out. The PortaPow one looks like it will work, but then so did the others.

Anybody know what is really implemented?
Does anyone know what portions of the USB2.0 Battery charging Specification protocols the nexus 7 uses. Is it just shorted DP/DM (DCP = Dedicated Charging Port)) or else it assumes SDP (standard data port)? Or does it look for CDP (Charging Data Port)? Does it reduce its charge current if the input voltage sags (like it might do with a 1A DCP). Does it look for ACA voltages?
Does the nexus charger just short DM/DP?

[Q] Charging the N4 with N7's charger.

Hello XDA,
As battery life is something people owning a Nexus 4 tend to struggle with in general, I've been wondering wether it affects my phone if I use my Nexus 7's (stock) charger for charging my Nexus 4. (As I would not want to receive a decreased battery life in the future due to using it) I've done a quick search on the forums and have found some threads, which in the end still contain a lot of controversy. Perhaps anyone with a good understanding of this can enlighten me?
Thanks in advance!

The N7 charger will not perform any differently than the N4 charger. Phone determines the load, and the current that it draws.

Well I am inclined to believe you, but why wouldn't LG choose to accompany the phone with a more powerful charger to begin with? As the stock charger from the N4, is rather... slow?

[Q] S4 I9505 for N00bs

Hi Guys, ive been part of the HTC One X scene and now i am getting an s4, question is i hate Touchwiz with a passion!! so i want to use an AOSP rom, my question is what is the easiest one to use and are modded kernals a good idea with this phone? regards,

I use Danvdh's GPE ROM. It basically converts your existing S4 into a Google Play Edition S4, but with some subtle enhancements. Being a GPE ROM, it also has the advantage of using Samsung libraries for its hardware, which makes it run more smoothly than the AOSP alternatives that use reverse engineered drivers.

I had been leaning to that Rom, what about kernels any that actually make a noticeable difference? I keep seeing fast charge pop up ?
Sent from my HTC One using XDA Free mobile app

Use the Googy Max kernel that's included, or use the more up-to-date Hulk kernel variant of Googy Max. Alucard's kernel reportedly has a battery drain issue and the stock kernel introduces random reboots. As for fast charging, I've not gone through every post in that thread so if there is a fast charge option I'm not aware of it.

Is there any idiots guide to do it? Lok
Sent from my HTC One using XDA Free mobile app

An idiot's guide to install the ROM? Root, install a custom recovery (TWRP recommended here), and install the ROM through recovery. The various kernels and ROM options are all in the zip, as it uses Aroma installer.

Easiest way to root? Still on kitkat if that makes a difference
Sent from my HTC One using XDA Free mobile app

CF-Autoroot. There should be a thread for it in S4 General.

I actually find the CM12 optimzed builds to be a bit snappier than GPE. But GPE is more stable and bug free. I had several problems with the latest CM12 builds.
You can always change roms afterwards. But I keep coming back to GPE The only downside is that there is no ktoonsez kernel for GPE 5.0.
It's an awesome kernel and the only one, that I know of, to offer GPU Overclocking.
Alucard and Googy-Max kernels are great too.
Fast charge is designed for USB. The USB current is lower than the AC current. This means that the phone takes a lot longer to charge via USB.
Fast charge substitutes AC to USB. Meaning that it will charge via USB with the same current as AC.

I was thinking of the rapid charging devices like the Nexus 6 have, where you get 50% power in roughly a half hour. Glad someone around here can keep me straight.

Strephon Alkhalikoi said:
I was thinking of the rapid charging devices like the Nexus 6 have, where you get 50% power in roughly a half hour. Glad someone around here can keep me straight.
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Well, it was mainly done to increase charging speed via USB, I think.
But you can also increase the current on AC charger. Which means it charges faster, similar to what you said.
I don't know what the default is on touchwiz stock kernel, but Googy set it at 1450 mAh for AC.
Alucard kernel comes with 1900 mAh for AC. Which means it charges relatively faster. Look at it as "Overclocking" your charger
But it may also reduce the battery's life.

Googy and Hulk allow you to set the AC and USB voltages, so I left USB alone but set AC to 1900. Its unlikely that battery life will be adversely affected by ramping up the amperage of the charging circuit, unless the battery gets exceptionally hot (it doesn't) in the process. The stock charger won't be damaged by doing this as the charger is rated for 2A in the first place. Third party chargers, as long as they're rated for 2A, won't be damaged. Smaller chargers will eventually fry.

I leave it at 1450. I'm in no hurry. Especially when I'm gaming

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.

Seeking lowered charging termination voltage ("BLE")

This is a feature that has shown up in custom kernels in the past but I can't find any that support it for the Nexus 6P.