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Support Nexus 7 charging is extremely (and annoyingly) SLOW

This is a very annoying problem that I can not put my finger on it.

I am not a heavy user of games that chew the life out of battery or anything. My usage is limited to browser, some video watching application that I seldomly use, watching movie trailers and I have an unhealthy addiction to Viggle :) I log in to draw something once or twice a day but I exit the application as soon as I am done.

When I clicked on the battery from the control panel menu, I see the biggest offender of battery life is the screen with 85+%. If Viggle is running, it is a distant second with 6-9% of battery consumption. Then the rest are all 1-2% levels of handful items. My screen brightness setting is in auto mode.

If there are any questions, I am using the charger that came with the tablet and I believe even the USB cord is the original one but don't quote me on the cord. It is a pretty thick one. Charger doesn't even get warm, very cool to touch as of today.

I usually keep the tablet on charger overnight with the screen turned off. If I left the charge somewhere in the teens percentage-wise, I am lucky if I find it above 80% in the morning, which is about 6 hours or more charging time. The same charger used to bring a dead battery to 90% or more charge in less tha 2 hours.

Together with not being sure, I think this problem started when my android version got upgraded to 4.2 from its original 4.1 but I did not pay attention to it at the time. Few days ago, I got the 4.3 update and I think the charging situation took a turn for the worse.

Today for instance, I turned the device off, before going to bed and plugged it in. I saw the charging battery logo and left it on my desk. I think it had something like 7-8% charge at that time. 7 hours later, I turned it on and it was at 53% which is odd, considering nothing was sucking the light out of battery by running anything.

Then I made some more measuring :

device turned off at 39%
1 hr of charging
device turned on at 45%
screen turned of while device is running nothing but whatever is in startup
1.5 hours of charging
charge level at 52%

These are very unusual values compared to old days. Does anyone know what the heck is happening to my battery ? I know batteries go bad in time but it is not even 1 year old and at this stage in battery life, few percentage points of capacity loss is expected but not at this level.

I'd like to know if anyone has experienced the same or similar symptoms and if you have a solution for it ?



#1 thenomad, Aug 11, 2013
The problem could very well be your charger. I wanted an extra charger at work, so I purchased one of these and have been very happy with it, especially because it has an extra port on it. I then purchased two more because I wanted extra chargers around the house, and this one charges the tablet quickly. You might try this and see if your problem is resolved. (I just learned that as a newbie, I'm not allowed to post a link, but search Amazon for a "CrazyOnDigital Home Wall Charger For Google Nexus 7, Kindle Fire, Kindle Fire HD 7" 8.9"(Black)")
#2 NASCARKev, Aug 11, 2013
Your USB cord could easily be most of the problem. The original cord wasn't very thick, but had large wires in it. It also has the name ASUS printed on the larger connector. The fact that you are saying the USB cord is "pretty thick" makes me think you aren't using the original.

USB cords other than the original are OK, as long as the conductors for the power are a larger gauge of wire. Look for lettering on the cord itself. (The original had none, at least on mine.) Somewhere it should say something like: "28AWG/IP+24AWG/2C"... Those numbers tell you that the data wires are 28 gauge, and the power wires are 24 gauge. (smaller number = larger wire) If there is no "+24AWG/2C" part, then all wires are the size first listed.

To charge in a decent amount of time, you really need to have 24 gauge wire on the power conductors. So the question now is," What are you using for a charging cable?"
#3 syzmic, Aug 11, 2013

Okay, as an electrical engineer, I agree with you on the importance of AWG ratings. And the cable has no ASUS logo on it. So I am assuming it is not the original cable. Yet, I have been using this cable for the past 5-6 months or so, since I moved my desk to a different part of the house at that time and it somehow worked fine when I first started using it. I mean 2 hours or so time for a full charge. Now 7 hours to accomplish less than 50% is a bit odd to me.
#4 thenomad, Aug 11, 2013
Non-original cable, but are you using the original Asus charger?

The Nexus 7 will charge from any charger (and with any cable) but the best case is the original charger and cable because of the unusually high charging current the device attempts to use. If the current can't be sourced without voltage drop the Nexus falls back to a very slow charge rate to prevent damage, and in this charging mode it will often not charge at all while in use and may take overnight to charge even when switched off.
#5 John Bean, Aug 12, 2013
Yes I am using the original ASUS charger, but, according to what I read above, I am not using the original cable. Again this cable worked fine up until few days ago. I mean almost full charge in 2-2,5 hrs rate. Now, the charging times are abysmal. I am trying to figure out if the last OS update to V4.3 had a modification to the charging process.
#6 thenomad, Aug 12, 2013
It did. There are reports that it will no longer charge (at all) from older USB ports that don't identify themselves as charging-enabled - ports that worked (slowly) before the update, so perhaps it is also doing more aggressive checking of any charging source.

I would try a different cable, preferably the original, and see what happens.
#7 John Bean, Aug 12, 2013
I had a similar problem to the OP - all of a sudden, charging became very slow (or non-existant if running Daydream when in the dock overnight).

I traced it to the cable. I wasn't using the original cable at the time, as that failed within a couple of weeks of me buying the Nexus 7. It was a fairly cheap cable, but I hadn't had any problems with it before. Rummaging through my box of cables, I ended up having to use an original HTC cable that came with my ye olde Desire to get a decent amount of current to the device.

I used an app called "Battery Monitor Widget" by 3c to help trace the fault, as it can display the mA input when charging and discharging (although you have to wait a while for the history to update, even when set to 60 second intervals).

#8 Rhyan, Aug 12, 2013
My original cable has long been gone. I mean I might have give it to someone or just buried in a cable pile somewhere. Looks like I will need to buy a USB power rated cable tomorrow.
#9 thenomad, Aug 12, 2013
I'm using the original charger and cable, and mine certainly has no problems getting fully charged overnight when starting from about 20%.
#10 Claghorn, Aug 12, 2013
I found that a lot of sellers don't list the AWG numbers on the cables they sell. Monoprice is a nice exception to this. They have a 6' cable PID:5458, that fills the bill nicely. If you like shorter cables, Meritline has a 3' one, part # 192-714-001 that has 24AWG power wires, but they don't say it in the description. (I have several of these is how I know.)

Your probable problem with the cable you are currently using is, that after several months of use, one or both of the power wires has partially broken (frayed), reducing the effective AWG rating of the conductor. [Retired electronics technician here. :)]
#11 syzmic, Aug 12, 2013
I came to realize the same thing, i.e., no AVG rating on USB cables. Checked Meritline for the part number you provided but it was a no-go. Otherwise I frequently buy from them and free shipping is great. Monoprice charges $1.49 for the cable with a shipping charge of $1.99 which I don't like. I will look for it elsewhere I think. S&H higher than actual product price is something that doesn't bode well with me.

In another related note, I realized, my cat used the plastic casing of the USB cable as a teeth scratching assistant at one section. Even though I don't see the conductors, there might be micro-punctures in the cable. I will look and see if I have a "more" intact USB cable somewhere in my house first.
#12 thenomad, Aug 13, 2013
I'm not fond of S&H being more than the price of the item either, but when I ordered 3 of them, there was only one shipping charge. That doesn't make it so bad. I hope they haven't changed that policy.

I don't know why you couldn't find the "192-714-001" cable on Meritline. When I do a search, it pops right up. I kind of expected that, as I currently have a pair of these on order. They shipped 2 days ago. :D
(Join Slickdeals. They will inform you when those cables go on sale again. My two on order cost a buck for the pair.)
#13 syzmic, Aug 13, 2013
The bright green USB cable I got out of a bin at Walgreen's for $5 works perfectly on my 3rd party charger.
#14 Claghorn, Aug 13, 2013
What hits me immediately is to skip the charger, connect THAT USB cable to a computer and time how long it takes to charge. If it's the same or faster, the charger is bad, as charging over USB is slower.

Just an idea.
#15 tedpc01, Aug 19, 2013
Well, OK. But you won't need a stopwatch to time it. What you WILL need is a calendar, as it will take forever. :rolleyes:

And charging by USB is slower than what? The USB is used to charge no matter what it is plugged into... (just saying)
#16 syzmic, Aug 19, 2013
I was just thinking his charger is slower than USB. Just an idea like I said, trying to narrow it down.
#17 tedpc01, Aug 19, 2013
I looked over on eBay and found a cable that solved my problem, now i get charged in 2 hours. My nexus rocks again!!!
#18 klimane, Aug 22, 2013
I agree something not right.

I had issues with the charging port wearing out - needed to bend the tabs on the USB port to get a reliable charge.
#19 Highland Ranger, Aug 26, 2013
Didn't read everything, but thought I'd throw in that the few times I've experienced this, it seems to be when left to charge overnight tucked under my pillow or a blanket, and inside the closed case. I think it's overheating and the charge circuit is shut off to prevent damage.

I've been careful to let it charge in areas with airflow since and it seems to charge at regular rate with stock charger and spare cable.
#20 TheAmazingDave, Aug 26, 2013
Although I've never had any charging issues on my 7.2 -- -- I tired of nightly having to plug-in the USB cable to charge.

So -- I ordered a wireless charger. Marvelous device.

Simply close the case on the 7.2 -- goes to sleep automatically and place on the charger pad.

It's as simple as just laying the covered device down on a table.

Next morning -- Simply grab and She's fully charged. NO cable - No muss -- No fuss.

#21 Sparky, Aug 26, 2013
PLEASE NOTE: I just received a new pair of cables, part# 192-714-001 from Meritline. They have changed manufacturers, or something. The cables no longer have the wire sizes printed on them, so I am not sure that the new ones actually have the 24AWG power wires.
#22 syzmic, Aug 27, 2013
It seems really unlikely that all of the cables I use have gone bad suddenly. I am going to try the wirely charger. It got such bad reviews when I first checked that I was loath to try it.
#23 pdiehr, Sep 17, 2013
Had same problem recently and I was using the original charger and cable BUT I was using a cheap ass USB cable extender. Removed the extension cable and me N7 charges just like before...
#24 turbocomppro, Sep 30, 2013
Did anyone see my other thread? My mother's N7 was charging very erratically, even with stock brick and cable. I ended up finding that the ribbon connector on the USB port (under the N7 back cover and under the speakers) was loose, on a unit that was sold as new.

Reseated the ribbon, and power monitoring shows it takes a charge between 1,500-1,900 mAh now, and charges in only a few hours as opposed to all night.

edit for link:
#25 TheAmazingDave, Oct 3, 2013