Trying to understand the current draw of a Samsung Galaxy S3

[Patrick]

On 01/02/2014 13:59, Gordon Levi wrote:

For five dollars with free shipping you may prefer this
http://tinyurl.com/maqfv9r>. I don't own anything similar so I can't
provide a recommendation. As I understand it, the cheap ones like this
can't pass through the data.

I've just copied a file to PC, from 'Samsung GT-P3110' via USB cable
with said device inline.

 

[Gordon Levi]

Patrick <invalid@invalid.invalid> wrote:

On 01/02/2014 13:59, Gordon Levi wrote:
For five dollars with free shipping you may prefer this
http://tinyurl.com/maqfv9r>. I don't own anything similar so I can't
provide a recommendation. As I understand it, the cheap ones like this
can't pass through the data.

I've just copied a file to PC, from 'Samsung GT-P3110' via USB cable
with said device inline.

Thanks for the correction Patrick. I have just ordered one!

 

[Geoffrey S. Mendelson]

(PeteCresswell) wrote:

Per Danny D.:
Wow. Today I removed the S3 from the wall charger,
and, within 5 hours, the battery was nearly dead.

When I looked to see what was consuming the power,
I found, much to my surprise, that "Google Play Services"
consumed more power than the Android operating system!

http://farm8.staticflickr.com/7412/12261909853_b6c685ceab_o.gif

The app that I use to remove unwanted system apps is called App Master.

It allows apps to be put in it's "Recycle Bin" from which they can be
restored.

So I'm not all that hesitant about uninstalling something. If the
device starts getting weird, I just restore it. The trick being, of
course, not to uninstall anything that would prevent App Master from
doing it's Restore thing...

Combining both of your posts, is it possible that since Google knows about
all of the apps you bought from them and tracks them, will it attempt to
restore them if you delete them?

I don't know for sure but I have seen automatic updating of apps on my
android devices, and if I bought them (even for free), they try to
reinstall.

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379

 

[Capt Rick]

On Sat, 01 Feb 2014 09:13:24 -0500, TJ <TJ@noneofyour.business> wrote:

On 02/01/2014 06:17 AM, Capt Rick wrote:
On Sat, 1 Feb 2014 07:08:11 +0000 (UTC), Danny D'Amico
danny@is.invalid> wrote in part:


I plan on sacrificing a USB cable to that I can hook an
ammeter in series to test the actual current flowing.

No need to sacrifice a USB cable. Measure the current going into the
cigarette lighter adapter. Measure without the Galaxy plugged in for
any idle current. Plug in the Galaxy. Subtract idle current then
multiply by 2.52 for a rough figure - 12.6V / 5V = 2.52. For more
accuracy measure the actual 12V Voltage and the actual 5V Voltage of
the USB output.

The current will be less on the 12V end because it is a step down
circuit. Just for example, if 1A on the 12V side, 12.6V X 1A = 12.6
Watts / 5V X 2.52A = 12.6 Watts.

Rick

Don't know about modern vehicles, but I believe that with older ones if
the vehicle is running, the alternator puts the voltage at more like
13.6V, especially if it's still charging the battery after starting the
engine. Could be higher with a high-output alternator. They cut back
once the battery is charged, but there is that period of time where it's
higher.

TJ

Yes TJ, the voltage is higher with the engine running. It's
_nominally_ 13.8V, but could really be anywhere from 12 to 15V
depending on engine RPM, load, and battery state of charge. That's why
I mentioned for more accuracy measure the actual 12V Voltage... I see
I didn't mention to do all this with the engine not running and the
ignition switch in ACC In that event the Voltage should be very
close to 12.6.

I also didn't mention the efficiency of the adapter, which could be
anywhere from 75 to 95%. But then I don't think he's looking for a
right-on-the-money current, but more of a ballpark figure. I could be
wrong.

Rick

 

[(PeteCresswell)]

Per Danny D.:

Wow. Today I removed the S3 from the wall charger,
and, within 5 hours, the battery was nearly dead.

When I looked to see what was consuming the power,
I found, much to my surprise, that "Google Play Services"
consumed more power than the Android operating system!

http://farm8.staticflickr.com/7412/12261909853_b6c685ceab_o.gif

The app that I use to remove unwanted system apps is called App Master.

It allows apps to be put in it's "Recycle Bin" from which they can be
restored.

So I'm not all that hesitant about uninstalling something. If the
device starts getting weird, I just restore it. The trick being, of
course, not to uninstall anything that would prevent App Master from
doing it's Restore thing...
--
Pete Cresswell

 

[(PeteCresswell)]

Per Geoffrey S. Mendelson:
>Combining both of your posts, is it possible that since Google knows >about all of the apps you bought from them and tracks them, will it >attempt restore them if you delete them?

Good catch. I never considered that.

I'll start checking. Push comes to shove, I suspect I can uninstall
whatever does those automatic updates.
--
Pete Cresswell

 

[tlvp]

On Sun, 2 Feb 2014 05:48:18 +0000 (UTC), mroberds@att.net wrote:

> ... hook an ammeter across the fuse ...

You want the fuse and the ammeter to *share* the current being drawn?
Or you want to measure the current being drawn *through* the fuse?
If the latter, put the ammeter *in series* with the fuse (not across it).

HTH. Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP.

 

[Gene E. Bloch]

On 2/02/2014, (PeteCresswell) posted:

Per Geoffrey S. Mendelson:
Combining both of your posts, is it possible that since Google knows
about all of the apps you bought from them and tracks them, will it
attempt restore them if you delete them?

Good catch. I never considered that.

I'll start checking. Push comes to shove, I suspect I can uninstall
whatever does those automatic updates.

Google has never tried to restore any app that I have deleted.

Of course, some Google or phone makers' apps can't be deleted. OTOH,
some of those can be disabled; I've never had a disabled app reenabled.

--
Gene E. Bloch (Stumbling Bloch)

 

[Gene E. Bloch]

On 2/02/2014, tlvp posted:

On Sun, 2 Feb 2014 05:48:18 +0000 (UTC), mroberds@att.net wrote:

... hook an ammeter across the fuse ...

You want the fuse and the ammeter to *share* the current being drawn?
Or you want to measure the current being drawn *through* the fuse?
If the latter, put the ammeter *in series* with the fuse (not across
it).

HTH. Cheers, -- tlvp

No: *replace* the fuse with the ammeter. Pull the fuse & plug the
ammeter's leads where the fuse's leads went (it's not easy!). Try
soldering wires to the leads of a blown fuse (that's not so easy
either).

Of course, if you knew the exact resistance of the fuse and had a
sufficiently sensitive voltmeter you could measure the drop across the
fuse. Good luck with that!

--
Gene E. Bloch (Stumbling Bloch)

 

[Danny D'Amico]

This article was pointed out to me by Jeff L. and it is interesting in that it
explained the Chinese standard, the EU standard, and the Apple standard of USB
charging circuits:
http://blog.curioussystem.com/2010/08/the-dirty-truth-about-usb-device-charging/

Apple, being different, used voltages for their charging circuitry:
- low current: 2.8 volts across Data(+)
- high current: 2.0 volts across Data(-)

The EU used a 1/8W 200 ohm resistor, & the Chinese simply short the data pins.

The five 1/8 watt resistor "hybrid" circuit in that article nicely explains how
a USB charger can work *either* for Apple (voltage) or EU (resistance) or
Chinese (short) charge circuits; but not all three at the same time!

 

[Danny D'Amico]

Another related article that Jeff L. pointed out today was this:
http://instructables.com/id/Modify-a-cheap-USB-charger-to-feed-an-iPod-iPhone

That article nicely further explains the Apple charging standard:
a) 2.0 V on D+ & 2.0 V on D- tells the Apple device it's a 500 mA port
b) 2.0 V on D+ & 2.8 V on D- tells the Apple device it's a 1 A port

 

[artleknock]

Going back to original query.
Ignoring all of the technical jargon, it could be that the GPS is
using power faster than it can be replaced.
According to the battery utility app on my Samsung Note 10.1 it takes
a very low battery in excess of 2.5hrs to charge on a mains charger,
but with a full battery the GPS will only function for 1hr and
39minutes. So the GPS is using power faster than even a mains
connection can replace it, it would be even faster with a USB
connection.

 

[Juan Wei]

Danny D. has written on 2/1/2014 10:45 PM:

On Sat, 01 Feb 2014 05:17:38 -0600, Capt Rick wrote:

No need to sacrifice a USB cable.
Measure the current going into the
cigarette lighter adapter.

Now why hadn't I thought of that!

I can just hook an ammeter across the fuse
for the cigarette lighter socket, which
will give me the current being consumed
with, and without the phone being charged!

(If you hook it across the fuse, you won't get the current you want.
Remove the fuse and connect the ammeter to the fuse terminals.)

 

[Rod Speed]

"TJ" <TJ@noneofyour.business> wrote in message
news:lch8t5$7c6$1@dont-email.me...

On 01/31/2014 12:17 PM, Danny D. wrote:
On Fri, 31 Jan 2014 07:01:29 -0800, dave wrote:

Turn off GPS.
Turn off mobile data
Voice and Text are not on Mobile Data.

Luckily, I don't even have mobile data.
I do use GPS navigation all the time in the car though.
That's the whole point!

If the phone can't keep up with the GPS while
on the car charger, um, what good is GPS?

Note: I have gone on long trips (4 hours), and
if the battery is charged (say, >50%) it stays
at about that level; but if the battery is low
(say <20%), then the battery steadily depletes.

That's the enigma I'm trying to understand.

Perhaps your best solution would be to use the phone as a phone, and
purchase a separate GPS unit to use for navigation.

I actually find that the iphone 5 does a much better job
as a GPS receiver than the TomTom 710 it replaces and
gets a lot more time on the internal battery with the
GPS turned on too, and is a lot more convenient to use
because it does everything and the TomTom doesn’t.