Develop Bugs

usb charge vs ac charge

Hey
Whenever ive had a phone with a usb port in the past ive usually charged it via USB connected to my PC. However, with the desire it takes about 45 mins to improve battery by 1% when connected to pc, whereas is takes about 1 min to do this when connected to AC. Ive never had this with any other phone which is why im wondering whether theres something wrong there
anyone else have this issue?

I'm pretty sure most devices do this.. any I've toyed with have..

it might be slower, but its never been this much slower. In fact, ive just had it plugged into usb for the last hour and the battery has gone DOWN 3%!!!!!

The current that you can draw through a USB port probably isn't as much! can't remember what the USB standard is but it's more that likely a lot lower than the AC charger

Yes, I am experiencing the same thing. On USB 1% every half an hour, on AC like 1% per minute. Still, I don't know what is causing this. The output power of AC and USB are different, but they shouldn't be this much.

is your laptop running on the mains or battery?
is your charging cable original (htc desire) ?

my laptop is running on the mains/AC but i am not using the cable that was originally bundled with the desire....should that make a difference though? Surely a USB cable is a USB cable?

Same here. Very slow on USB.
Wiki says this:
However, many devices require more power than this method can provide, and will not work in this type of hub.
USB current (related to power) is allocated in units of 100 mA up to a maximum total of 500 mA per port.
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ive generally always charged my phone via USB and never had this problem with any phone. the desire must be sooo power hungry. Im actually at a stage now where even if i plug it into the USB port, it still loses charge

One usb hub can provide up to 500 miliamps of current, one port just 256. The ac adapter can give you 1000 ma. So do the calculations yourself
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Since I have had my desire I have never charged it via the charger my pc charges it even when its turned off and I've never had any problems with charge speed.
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i found the htc cable to be more effective than a micro usb one from samsung.

I've charged my phone from my PC loads of times. Takes about twice as long (roughly, I've never actually timed it).
Definitely not 1% per half hour though!

What is your setup and are you doing with the phone whilst it's connected?
With WiFi and 3G and the screen left on, I get +1% every 3.6mins using the PC USB.
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- Sent via my HTC Desire -

no, i definately dont get it charge that quick. Also, for the record, when using gps connected to a car charger, it doesnt ever charge, it only loses charge at a much slower rate (not good for long journeys!) unless i switch the screen off
When its connected to the pc im usually not doing anything with it. If even tried it with the phone switched off before, charged it like this for an hour and then when i turned it back on it had only charged by 2%
what do you want to know about the setup? Could it actually have something to do with the fact im not using the original bundled USB cable? I just cant see that being a factor

something is definitly wrong with either your cable your phone.
Let's try to cancel out one of those factors:
-have you tried using a different able?
I have NEVER used the AC charger, i've always used the usb charging method, and it takes about 2 hours for a half charge.

ill try using a different cable and see what happens. could the fact im charging it off a netbook be a problem? i wouldnt have thought so as i always charged my last phone (touch diamond) off this netbook too

ok, so it seems the USB cable used DOES matter. When using the original one it charges a lot quicker via USB ... AND AC
i didnt realise different usb cables have different power transfer rates....i guess now i do

Do this test.
Try to charge the phone while it's off.
The power controller of the phone needs to split the power between the phone requirements and the charging of the battery.
I think that your phone is drawing to much power so there is very little left for the battery charge.
So 1. test the usb cable 2. test the power consumption of your phone.

I have no problems charging my phone, when it's connected to my desktop.
Use it all the time at work.

Charging via USB on computer

My device charges very slowly if the display is off. If the display is on it does not charge at all.
I've installed the Samsung drivers from the website. Is anyone else able to charge their device via USB? I need to know if I should exchange mine.
Sent from my SGH-T989 using XDA App

I was able to charge my sgs2 yesterday at work through the usb port. It might be the phone, or maybe the usb port you are trying to use doesn't have enough juice to charge the phone? have you tried another usb port on the computer?

usb will always charge really slow compared to an wall outlet

Yes I have tried multiple ports, computers, and cables. Oh well, I guess I'll live with it.
Sent from my SGH-T989 using XDA App

+1
dimitrie said:
usb will always charge really slow compared to an wall outlet
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what he said
if you want fast charging, do it from a wall outlet

jasontx said:
My device charges very slowly if the display is off. If the display is on it does not charge at all.
I've installed the Samsung drivers from the website. Is anyone else able to charge their device via USB? I need to know if I should exchange mine.
Sent from my SGH-T989 using XDA App
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Click to collapse
USB supplies max 500mA. Is probably half what the wall charger is giving you. Nexus S is only 750. My guess gsII is 1000 (1A). iPad charger is 2A.
Edit: no a higher power one than the stock charger won't charge the phone faster in a noticeable way. Charging circuits in remotely modern phones limit current to that safe max. If they don't you're probably risking damaging your phone.
Sent from my Nexus S using Tapatalk

I understand that the USB on the computer is weaker. I was surprised to see that when the phone was connected to the computer, screen on, and streaming music that my battery was actually reducing slowly. I would expect the opposite and this behavior seems abnormal.
Sent from my SGH-T989 using XDA App

that's exactly the reason why in car i use the 2A charger (2000 mAh), and in house i use 1000 mAh wall charger
if i leave it at the computer USB charging, i've to keep it iddle for it to charge after like... 4+ hours
that's usually what i do at the work place, so i keep the battery topped up, for when i need to jump back in the road
as long as you have WiFi on, or 3G/4G on, or if the CPU is in high activity, you'll never see the charge ever reaching the battery.
i always keep a spare wall charger at the office as well for times when i need a quick charge

Thanks for the input everyone! I'm glad it's not defective cause I love this phone!
Sent from my SGH-T989 using XDA App

My issue is a little different but decided against another thread. My phone will not charge with any other cable. Has to be pluged in to oem cable. I left it all night on my old phones charger and woke up with it almost dead. Plugged into oem it just charges super slow. Should i take it back?
Sent from my SGH-T989 using Tapatalk

Does the other micro USB cable work with other devices? If not, might be a defective cable.
On a side note, who prefers to charge via 500mah vs 1A? I have been charging my phone since day one using my printer, as well as my old Iphone. My battery performance is great! +24 hours on a single charge with moderate browsing 50/50 wifi and 4g. I typically enable the "power save" feature with minimal brightness and 15 sec screen timeout.

I worked on other devices
Sent from my SGH-T989 using Tapatalk

[Q] Charging problem
I have an issue that has popped up today. When charging through PC, the phone (not battery) is getting pretty hot and losing charge. I'm not sure what could be causing it. I stopped all extra processes and turned off the screen. This is not occurring when the phone is off.

[Q] Charging Sony Ericsson Xperia Play

Hello!
I know that SE recommends charging its phones frequently unlike Nokia. And they don't even prohibit having it plugged in continuously.
Also it is recommended that we should use the official charger and adapter for charging, that I understand. But what about charging through USB, because we connect USB without adapter; so is it save to charge via any computer around you?
For example, whenever I fly I can see a USB in front of my seat but am afraid to charge even though the battery is continuously leaking.
Can anyone more familiar with the SE products recommend me on this?
Thank you for your time.

Jack Shepard said:
Hello!
I know that SE recommends charging its phones frequently unlike Nokia. And they don't even prohibit having it plugged in continuously.
Also it is recommended that we should use the official charger and adapter for charging, that I understand. But what about charging through USB, because we connect USB without adapter; so is it save to charge via any computer around you?
For example, whenever I fly I can see a USB in front of my seat but am afraid to charge even though the battery is continuously leaking.
Can anyone more familiar with the SE products recommend me on this?
Thank you for your time.
Click to expand...
Click to collapse
USB carries alot less ampage than the standard charger so it's totally safe, although your device will charge at about half the speed it will via the plug

Ok thank you.
Sent from my R800i using XDA App

Anyone else have issues charging via computer USB?

I seem to have an issue that my phone never charges whilst connected via USB to my Macbook Pro. I have also tested on a Windows machine and have the same issue.
I was able to charge my Sensation over USB and I know that one of the ports on the Macbook has a higher output for charging but it makes no difference.
The phone states that it is charging but the percentage charge continues to drop. If I switch the power off it will charge. There doesn't appear to be any big battery drains though. I ran for a day and twelve hours over the weekend and charged at 40 percent.
Has anyone else the same issue?
Btw, I am on stock 4.0.2, rooted but not running anything else that should have any affect
Sent from my Galaxy Nexus using Tapatalk

How old is your macbook pro? Or more to the point, do you know if it has USB 3.0 ports? If your higher output ports are just 2.0 (and your computer is describing them as such compared to the older 1.0 spec) then you are stuck at 0.5A (half of wall charger output). USB 3.0 goes up to 0.9A, but I don't know if there are any catches in terms of devices needing to request the bump.
When you say that it charges if you switch the power off, do you mean it only works if you actually power down the phone? As in, leaving it sleeping plugged in, it still won't charge? Keep in mind that actively using the phone with the brightness turned up high could result in overpowering the .5A current in.
Unless you know someone else with a GN you can test you might just want to take it into the store and have them try it there/consider a replacement if it's defective. Also worth exploring if it's just the battery is defunct, if you have access to another one.

aidanbree said:
I know that one of the ports on the Macbook has a higher output for charging but it makes no difference.
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Click to collapse
Really? Source?
Doing a tad of research it seems some models front (closer to the front) USB port has slightly higher output than the back (closer to the screen) USB port because the back one shares a USB controller with internal components.
It couldn't be noticeable though, they're both simply rated at .5A .
Has anyone else the same issue?
Btw, I am on stock 4.0.2, rooted but not running anything else that should have any affect
Click to expand...
Click to collapse
I charge my 4.0.2 stock GSM Nexus off of my MacBookPro almost every night without issues. Using both an HTC cable and the Samsung cable.
JoeSyr said:
How old is your macbook pro? Or more to the point, do you know if it has USB 3.0 ports?
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Click to collapse
MacBooks don't have USB 3.0. Its always been standard USB 2.0 afaik.
I'd also recommend that OP check different cables and computers, or different batteries if possible.

I have the exact issue. If I charge via USB on ANY laptop/computer it takes forever and if I'm using the phone as it's charging it uses more power than being supplied so it loses battery life even though it's plugged in.
I had this problem on my iPad too. It seems they need more power to charge but can still "trickle" charge off of a standard USB port.
My batter was at 10% last night, plugged it in to my laptop and sent some texts and left the display on (dev settings), about 10 min. latter it was at 4%.

I mean to post this last week!
See the screenshot....Status 'Charging' however as you see from the lower part of the screen, it has clearly stopped charging some time ago (about 3 hours earlier!)
It turns out that the CABLE was the issue....I thought all Micro USB cables were created equal, evidently not
Any ideas what the differences are in micro USB cables and how to identify which ones 'work' and which don't? I bought 10 from ebay which all seem not to charge from USB

I've had no problems charging via my pc using Samsung or Motorola cables. It charges slower but it still works.

Charge issues with new S20

Hello,
I have a question about the charge of my new S20 (Exynos version):
1) connected to the charger it charges (small 'lightning bolt" on the battery symbol).
2) connected to a booted PC it charges (same for the lightning symbol)
3) connected to the same PC in standby: the symbol appears for a fraction of a second then disappears and it does not charge. It is the same cable and USB plug as in case 2.
4) PC in standby: other USB port / other cable: it is the same, charge symbol very brief then nothing, it does not charge.
Another phone charges without any problem with the same cables/USB socket on the PC in standby ... I do not understand what is wrong.
Same issue with the S20 plugged to another PC ... but ok with other phones
An expert opinion? Thanks in advance.

Its charging board issue
Same issue faced in my s9 then chaging baord changed by service center

I don't understand the "charging" board problem : the phone charges with the same cable when the PC is on, with a charger, with USB in the car...
I was thinking that maybe when the PC is in sleep mode there is not enough power going through the USB port and it won't charge this phone model ?

I think I get a possible answer to my question :
---> using a shorter (about 1 feet only - Aukey brand) USB-A to USB-C cable allows to charge the S20 while the PC is in sleep mode. Any longer cable will only charge the other phones.
--> I guess the S20 require more "power" from an USB port to start recharging. Of course while the PC is on it must have more power as it works even with a longer cable.

Are all the jacks/ports clean and free of debris?
Are the cables good? Partial cable failures happen and charging anomolies is how it will first manifest its self many times.
You'll get much faster charging using the Samsung brick... best to limit charge to 90%, ideally 60-70% to lengthen battery life.

Yes the phone is 2 weeks "old" so no debris in port. It is working flawlessly except when trying to charge it when the PC is in sleep mode ... if the cable is too long.
But I'll use the S9 or S20 charger so it'll be ok.

It doesnt sound like your phone's fault but usb port in your motherboard - if it works fine while using charger then i wouldnt worry

if it works fine while using charger then i wouldnt worry
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Agreed ! Even I think the USB port is working fine with every other (older) phone ... but it seems this S20 requires more "energy" to start charging. It is the same while trying with a laptop in sleep mode.

Why would you charge it over pc? Isnt it super slow?
Sent from my SM-G985F using Tapatalk

Explanation:
The ports on yor pc when it's sleeping are in power saving mode. It works with a shorter cable because of something called inner resistance of the cable. When the cable is longer but made of the same material it has a bigger resistance therefore the phone does not get enough current to charge. You see the bolt icon for a bit because of a current peak coming from the usb port. Then the phone thinks "damn, that's not enough power" and stops charging.
All of this means that when you connect your phone to charge when the pc is not sleeping it becomes barely enough current to charge, but nevertheless it becomes something, that's why it charges.
Faulty charging board and etc. is not the problem, there is actually no problem. Your phone just needs a current maybe over 1A/5V to start charging, your port probably doesn't have that capacity, especially when pc is sleeping.
Just use the charger, it's much faster and doesn't stress the battery for a long periods of time.

honor701 said:
Explanation:
The ports on yor pc when it's sleeping are in power saving mode. It works with a shorter cable because of something called inner resistance of the cable. When the cable is longer but made of the same material it has a bigger resistance therefore the phone does not get enough current to charge. You see the bolt icon for a bit because of a current peak coming from the usb port. Then the phone thinks "damn, that's not enough power" and stops charging.
All of this means that when you connect your phone to charge when the pc is not sleeping it becomes barely enough current to charge, but nevertheless it becomes something, that's why it charges.
Faulty charging board and etc. is not the problem, there is actually no problem. Your phone just needs a current maybe over 1A/5V to start charging, your port probably doesn't have that capacity, especially when pc is sleeping.
Just use the charger, it's much faster and doesn't stress the battery for a long periods of time.
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Thanks a lot for you technical explanations. I am using a wallcharger instead of charging the phone overnight hooked to the Pc in sleep mode.