Need recommendation for USB power analyzer tool.

[David Farber]

I have various USB chargers, cords, and portable devices around the
house. One of my devices, a Kindle Fire from around 2013, which works
fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't
know. For example, it seems to take much longer to go from 15% to 16%
than from 95%-100%. In any case, I'd be curious to know how much the
charging current is fluctuating and if there is any variation in
performance between the wall chargers I have in my drawer. There's a
very large selection of USB power analyzers available but I mostly want
something that will test "C" ports as well as the older ones. Any
recommendations? It seems that every review I read contains more than a
few complaints about reliability and sturdiness.

Thanks for your reply.
--
David Farber
Los Osos, CA

[legg]

More likely to be a non-linearity in the gauge monitoring
method. A 15% gauge is a crude guess - a 95% gauge will
depend on settings and tolerances. Both reported values
will likely shift dramatically when transferring from charge
to discharge mode or vice versa.

A linear charger, thermally limited, will be more restricted
in delivering power when the battery terminal voltage is lower
(bigger drop across the regulator). Linears will only be found
in the oldest or cheapest devices, at USB power and voltage
levels.

The deviation you've noted is probably not worth the time,
trouble or expense to pursue, unless you're in the design/
build/test/repair/volume-trade businesses.

RL

[Peter W.]

Consider a battery very similar to a clock spring. And the charger similar to the key winding that spring. The key turns at a constant rate, so the first 30 (of 100) turns seems to do almost nothing. Whereas the last turn requires the most effort and gives the largest measurable results. The gauge that you are reading measures the tension on the spring, not how fully it is wound, but for practical purposes, the same thing at the end of the process. Charging a battery is by no means similar to filling a gas tank - just keep that in mind.

Peter Wieck
Melrose Park, PA

[David Farber]

Hi RL,

Thanks for all those operational details but these USB power meters are
not that expensive:

https://www.amazon.com/s?k=usb+power+analyzer&sprefix=usb+power+anal%2Caps%2C502

Most of them are in the $10-$40 range. My Kindle can take more than 8
hours to charge so I'd like to do some investigating.

[David Farber]

Hi Peter,

Funny you should mention the clock spring analogy. Last year I completed
my first course in clock repair. I was motivated to do so when a 100+
year old mantel clock stopped functioning. It was professionally
repaired many years ago and it did very well for 10 years after that.
When it stopped working again, I really wanted to learn how to do my own
repairs.

Getting back to the USB charging issue, I was hoping someone in this
group had a power meter in their toolbox and could recommend one.

[Clifford Heath]

On 6/2/22 8:10 am, Peter W. wrote:
> Consider a battery very similar to a clock spring. And the charger similar to the key winding that spring. The key turns at a constant rate, so the first 30 (of 100) turns seems to do almost nothing. Whereas the last turn requires the most effort and gives the largest measurable results.

Thanks for demonstrating to us that you know almost nothing about either
clock springs or battery chargers!

Clock springs are usually retained inside a barrel (except in the
cheapest clocks), so that each turn of the winding key unfurls another
rotation of the spring from being tight against the inside of the rest
of the spring. This results in *very little* progression of spring force
from run-down to fully wound. This is essential to proper time-keeping,
depending on the Q of the escapement mechanism (a Q of say 100 means
that the spring force can affect 1% of the clock's rate, clearly
unacceptable).

Battery chargers radically lower the charge rate when the battery gets
above about 80% full. The key *doesn't* turn at a constant rate.

[Mike Coon]

In article <stmh5d$shc$1...@dont-email.me>, farberbe...@aol.com
says...

I think this was the one I bought. I am very happy with it but don't
have much need for the power sink add-on or the built-in mAh accumulator
etc. I think it also monitors the charge control negotiation and
displays the result. There's a user-manual PDF link.

[Peter W.]

> Clock springs are usually retained inside a barrel (except in the
> cheapest clocks), so that each turn of the winding key unfurls another
> rotation of the spring from being tight against the inside of the rest
> of the spring. This results in *very little* progression of spring force
> from run-down to fully wound. This is essential to proper time-keeping,
> depending on the Q of the escapement mechanism (a Q of say 100 means
> that the spring force can affect 1% of the clock's rate, clearly
> unacceptable).

Here in the US, spring-driven pendulum clocks did not, and do not, for the most part, use barrels. They did, however, use the deadbeat escapement (Seth Thomas patent in the US) that does tolerate a wide range of spring force. Making accurate clocks much cheaper than before, as to get that level of accuracy, they often required a fusee drive. And for exactly the reason given. Any escapement with backlash as you suggest, allows the drive force (spring) to overcome the pendulum swing, introducing all sorts of inaccuracy.

[legg]

On Sat, 5 Feb 2022 13:43:23 -0800, David Farber

Overnight charging time of a Kindle-era device is not unusual.
If you are relying on the Kindles gauge for reporting, the most
accurate monitor will be your memory/experience in converting
those numbers to the practical performance delivered.

As your issue is slow charge time and not reducing run-time,
keeping the thing plugged in or replacing the battery probably
won't resolve it.

I encounter lousy gauges in expensive equipment all the time,
but repairing/improving them usually isn't an option. Once
the programmer has ben paid, at time of development, that's
what you're going to get.

I don't know that having a second gauge telling you something
different is going to help - they can only tell you what
current is flowing through USB power lines: not what current
is flowing into or out of the internal battery, before or
after conversion, dependent on direction of current flow.

RL

[Mike Coon]

In article <56df672b-edcb-4e9e...@googlegroups.com>,
peterw...@gmail.com says...

Anyone really interested in clock mechanisms could study "chain fusee"
https://en.wikipedia.org/wiki/Fusee_(horology)

[David Farber]

Hi Mike,

Did you inadvertently leave out the description of, "... the one I bought"?

[legg]

On Sun, 06 Feb 2022 07:19:16 +0000, Charlie+ <cha...@xxx.net> wrote:

>On Sat, 5 Feb 2022 10:54:40 -0800, David Farber

><farberbe...@aol.com> wrote as underneath :

>I have about 4 different makes/types over the years all Chinese, all
>work on the A USB plug/socket Id have to find adaptors for use with
>USBC. Just get the cheapest from eBay but make sure is counts mAh
>cumulative with a reset as well as V and A, some dont. Some will read A
>to .000 most only do 2 places. C+

These will not tell you actual battery status as they have no access
to the battery terminals - only converter socket input and output.

Currents will differ on both sides of the converters, in both
directions and the external dongle will ignore the influence of
both battery charging efficiency and converter losses in the
transactions.

. . . but then so do most built-in gauges, even for varying internal
consumption. The best you'll ever get is a ball park estimate that
your own experience has to qualify.

RL

[Mike Coon]

In article <stp26i$vca$1...@dont-email.me>, farberbe...@aol.com
says...

I didn't do it on purpose(!), and browser history has helped me get back
to the page: <https://www.amazon.com/Digital-Multimeter-Current-
Detector-delivery/dp/B07P252NY2/ref=sr_1_2?
keywords=usb+power+analyzer&qid=1644139878&sprefix=usb+power+anal%2Caps%
2C502&sr=8-2#descriptionAndDetails>

Link to manual: https://m.media-amazon.com/images/I/91cIyXAmu8L.pdf

[Jeff Liebermann]

On Sat, 5 Feb 2022 10:54:40 -0800, David Farber

<farberbe...@aol.com> wrote:

>I have various USB chargers, cords, and portable devices around the
>house. One of my devices, a Kindle Fire from around 2013,

That's 9 years old. You could be dealing with an almost dead battery.

Complaint: EVERY time you post a question, you either leave out or
truncate the details on what you're working with. Some Kindle Fire
models have "issues" and it's helpful to look for these "issues" or
recalls before assaulting the alleged symptoms. In this case,
None/HD/HDX/Kids, screen size, and what year Kindle Fire. Extra
credit for some details on the charger.
<https://www.mobilefun.co.uk/blog/2014/07/how-to-identify-your-kindle-model/>

>it seems to take much longer to go from 15% to 16%
>than from 95%-100%.

Hmmm... That's about what I would guess happens when you plug in an
underpowered charger. As I vaguely recall, some of the Kindle tablets
required a 5V 1.5A or 2.0A charger. Commodity chargers only deliver
0.5A. If the USB controller chip in the charger is over-heating, I
would expect something similar to what you're experiencing.

Perhaps providing how long it takes (in minutes) might also be
helpful? How long did it take to charge when it was new?

>In any case, I'd be curious to know how much the
>charging current is fluctuating and if there is any variation in
>performance between the wall chargers I have in my drawer.

You won't see much of that with an inline USB power meter unless you
want to record voltage and current every few minutes and draw a graph.
Something like this:
"USB Current Sensor"
<https://www.sparkfun.com/products/18016>
Software:
<https://github.com/sparkfunX/USB_Current_Sensor>
Setup your computah as a data logger and measure the voltage output
produced by the current sensor (1amp = 1volt). Graph the results and
you can see what it's doing. My guess(tm) is that the graph is going
to be far more erratic than you've already observed. If you don't
want a pretty graph, just use the current senor and put voltmeters
across the 5V line for the voltage, and across the output for current.

Also, put an oscilloscope across USB 5V line. You might see
oscillation and/or noise spikes.

>There's a
>very large selection of USB power analyzers available but I mostly want
>something that will test "C" ports as well as the older ones. Any
>recommendations? It seems that every review I read contains more than a
>few complaints about reliability and sturdiness.

I only have a pile of USB 2.0 type volt/amp USB meters. For fun, I
put them all in series and compared readings. Not too horrible +/-5%
on both voltage and current. However, you need something that will do
USB 3.0:
<https://www.ebay.com/sch/i.html?_nkw=usb+3.0+tester>

>Thanks for your reply.

Gone to split some more firewood.

--
Jeff Liebermann je...@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

[Clifford Heath]

Deadbeat removes one source of inaccuracy, but at the end of the day,
the spring has to deliver power to the pendulum to keep it swinging, and
that coupling varies with spring force. The bottom line is that it's
easier to e.g. use a heavier pendulum than it is to make a spring with a
flatter power curve. The Taiwanese 31-day clocks can often tolerate a
pendulum 3x heavier, and that dramatically improves their timekeeping.

CH

[David Farber]

Hi Jeff and all the other contributors to this group,

I really do appreciate all the feedback I get from this community. I've
been posting messages and getting expert help here for over 20 years.

As to your complaint about me leaving out important details every time,
I am not doing that intentionally. I was expecting to purchase a USB
tool that would help me figure out if one of my chargers, cords, or USB
port on the Kindle were intermittent. I didn't think that it would be a
manufacturing glitch or defect specific to this device.

The Kindle model is: P48WVB4 otherwise known as a Fire HD (3rd
generation) with a 7" screen. On the back, near the model number it says
"Input: 5.0 VDC MAX 1.8A" I received the device 2nd hand when the owner
upgraded to a new one. I don't have the original charger. I have three
chargers which came from various devices and sources. Two of them are
5.0 VDC 1A and the third one is, 5.0 VDC 0.85A. I have three USB cords.
One is quite old and I suspect this is part of the problem.

I viewed the link to the current sensor tool you mentioned
(https://github.com/sparkfunX/USB_Current_Sensor). Though it does not
have a display, it does have output terminals which the others do not.
Again, I think the problem my Kindle has is a loose connection or a bad
wire that can be easily detected by just monitoring the current while
tapping on the connectors and flexing the wires. The battery when fully
charged, will last around a week before needing to be recharged. I use
it from 1-3 hours a day and leave the wireless disabled and brightness
set to one step above minimum as I read in the evening with the text set
to a white font and the background set to dark.

[Jeff Liebermann]

On Sun, 6 Feb 2022 16:34:35 -0800, David Farber
<farberbe...@aol.com> wrote:
>The Kindle model is: P48WVB4 otherwise known as a Fire HD (3rd
>generation) with a 7" screen.

In the Amazonian language, that's a
"Kindle Fire HD 7, 2013, 3rd Generation"
<https://developer.amazon.com/docs/fire-tablets/ft-device-specifications-firehd-models.html?v=firehd_2013>
Note that this is the 2nd version of the Kindle Fire HD 7, but since
it was released in the 3rd year after the original, Amazon decided to
call it the 3rd generation. Bigger numbers are better.

I couldn't find anything that looked like a manufacturer's defect or
chronic problem, just the usual bugs and glitches:
<https://www.androidauthority.com/amazon-fire-tablet-problems-fixes-539370/>

> On the back, near the model number it says
>"Input: 5.0 VDC MAX 1.8A"

Bingo. That's either a 2Amp or 10 Watt charger. I found a few
references that indicate that the Kindle Fire HD 7 3rd generation
supports PD (power delivery) for fast charging. You might want to
borrow a 10 watt or 15 watt PD charger and see if it magically fixing
the charge time problem.

>I received the device 2nd hand when the owner
>upgraded to a new one. I don't have the original charger.

Sigh. He probably kept the PD charger (if that's what the Kindle Fire
HD 7 3rd generation uses).

>I have three
>chargers which came from various devices and sources. Two of them are
>5.0 VDC 1A and the third one is, 5.0 VDC 0.85A.

Both of those chargers should default to charging at 5V 0.5A. They'll
probably work, but very sloooooooowly.

>I have three USB cords.
>One is quite old and I suspect this is part of the problem.

I'll assume USB-C cables. A large percentage of the USB-C cables seem
to use very fine wire and therefore have a substantial voltage drop.
Phones, tablets, gizmos, and the guys who wrote the USB specs, will do
strange things if the voltage drops below:
5.0V -5% = 4.75V
A bad cable might be a problem, but I don't think so. When I see bad
cables, it's usually very "digital". It either works, or it doesn't,
with nothing in between.

>I viewed the link to the current sensor tool you mentioned
>(https://github.com/sparkfunX/USB_Current_Sensor). Though it does not
>have a display, it does have output terminals which the others do not.

Please re-read what I wrote. You need to supply a voltmeter (DVM) in
order to read the current. The device converts USB current into a
measurable voltage (1Amp = 1Volt) while introducing only a tiny
voltage loss.

>Again, I think the problem my Kindle has is a loose connection or a bad
>wire that can be easily detected by just monitoring the current while
>tapping on the connectors and flexing the wires.

OK. I give up. Please purchase a USB 3.0 tester, any tester, and see
if it can detect an intermittent cable or connector. When that fails,
come back here and I'll try to convince you to try a 10 watt (or 15
watt) charger, or consider a replacement battery.
"How to Replace Your Amazon Kindle Fire HD 7 3rd Generation Battery"
<https://www.youtube.com/watch?v=4IMHHMM8sqg>
<https://newpower99.com/products/amazon-kindle-fire-hd-3rd-generation-battery-replacement-kit>
Hmmm... a bit expensive. More batteries:
<https://www.ebay.com/sch/i.html?_nkw=amazon+kindle+fire+hd+3rd+generation+battery>

>The battery when fully
>charged, will last around a week before needing to be recharged. I use
>it from 1-3 hours a day and leave the wireless disabled and brightness
>set to one step above minimum as I read in the evening with the text set
>to a white font and the background set to dark.

I can't tell much from that without knowing how long it would run
under similar conditions when it was new. CNet test show 9.3 hrs
runtime for their video test.
<https://www.cnet.com/reviews/amazon-kindle-fire-hd-2013-review/>

[Jeff Liebermann]

On Sun, 06 Feb 2022 18:54:30 -0800, Jeff Liebermann <je...@cruzio.com>
wrote:

>I found a few
>references that indicate that the Kindle Fire HD 7 3rd generation
>supports PD (power delivery) for fast charging.

That's wrong. I did some more digging and could not find any
references to the Kindle Fire HD 7 2013 3rd generation supporting PD
(power delivery). The closest approximation to a spec sheet doesn't
mention PD (or any other fast charging specs):
<https://en.wikipedia.org/wiki/Fire_HD>
Therefore, any 5V charger that will provide 2amps (10 watts) and a USB
2.0 Micro-B connector, should work.

[whit3rd]

On Saturday, February 5, 2022 at 1:43:25 PM UTC-8, David Farber wrote:
> On 2/5/2022 1:01 PM, legg wrote:
> > On Sat, 5 Feb 2022 10:54:40 -0800, David Farber
> > <farberbe...@aol.com> wrote:
> >
> >> I have various USB chargers, cords, and portable devices around the
> >> house. One of my devices, a Kindle Fire from around 2013, which works
> >> fine, seems to have a nonlinear charging rate. Maybe that's OK. I don't
> >> know. For example, it seems to take much longer to go from 15% to 16%
> >> than from 95%-100%. In any case, I'd be curious to know how much the
> >> charging current is fluctuating and if there is any variation in
> >> performance between the wall chargers I have in my drawer.

> > The deviation you've noted is probably not worth the time,
> > trouble or expense to pursue, unless you're in the design/
> > build/test/repair/volume-trade businesses.

The under-$10 items from Banggood and other marketers are adequate to
tell if y our charge power supply can handle 100/500/1000/2000 mA currents,
and if the voltage is correct. Some low-end USB sources are low-powered, some
are not, and all the USB chargeables are different; sometimes it's nice to match
the best charge source with the tablet that needs it. It won't tell you power, exactly, just
monitors average current and voltage, but that's a good start.

Beware, type C connections, as well as mini-B, micro-B, B, A, OTG and USB SuperSpeed, may
not all work with any particular box; only the power current and voltage are fully compatible,
not the connectors and data-transfer particulars.

[David Farber]

On 2/6/2022 7:07 PM, Jeff Liebermann wrote:
> On Sun, 06 Feb 2022 18:54:30 -0800, Jeff Liebermann <je...@cruzio.com>
> wrote:
>
>> I found a few
>> references that indicate that the Kindle Fire HD 7 3rd generation
>> supports PD (power delivery) for fast charging.
>
> That's wrong. I did some more digging and could not find any
> references to the Kindle Fire HD 7 2013 3rd generation supporting PD
> (power delivery). The closest approximation to a spec sheet doesn't
> mention PD (or any other fast charging specs):
> <https://en.wikipedia.org/wiki/Fire_HD>
> Therefore, any 5V charger that will provide 2amps (10 watts) and a USB
> 2.0 Micro-B connector, should work.
>

I bought the MarkerHawk USB tester, Model3.
https://www.amazon.com/dp/B07DCSNHNB
I've been using it for a while now and it's quite good though it's not
enclosed in a case and the buttons (which are bare microswitches) are
mounted sideways AND recessed so they're not that easy to press. Also,
you cannot view all the data on one screen. Most notably to view the
elapsed charging time you need several button presses to switch screens
and then several more button presses to return to the main screen. The
features are nice but I wish I had gotten the 3B model which includes
Bluetooth capabilities. This would have allowed me to use the included
software on my laptop. Anyway, I noticed the biggest effect on the
charging current was the type of cord I was using. I have a couple of
skinny micro USB cords and one thicker cord. The thicker cord will
register 3 times as much current as the thinner ones and that's why the
charging times were not consistent.

I performed a test last night using the thicker cord with the Kindle
registering 15% remaining charge. After two hours, the numbers were very
consistent. The intervals of my readings varied from 5 to 30 minutes but
the percent increase charge per minute varied only slightly with the
average being 2.38 minutes per one percent increase in charge. The
charging current was maximum during the first 15 minutes starting at
1.15A and dropping to 1.09A after 15 minutes. Then for the next 35
minutes, the charging current was constant at 0.86A. The percentage
charge was now at 37%. Then for the next 60 minutes, the current dropped
to 0.67A and the percentage charge was 60%. At this point, the power was
accidentally interrupted and when I plugged it back in again, the
charging current jumped back up to over 1A and the tester's clock reset
to 0. I felt at this point I had enough data to get an idea of how
things were progressing so I stopped monitoring the charging current.

In summary, it's a nice tool to use but the owner's manual...

https://drive.google.com/file/d/1ZFC9TEPUBI5vD081lVSdVgsmeWRnaqi9/view?usp=sharing

...takes some time to absorb as it's apparently been translated from
another language. Maybe one of you could explain the importance (or
unimportance) in knowing the voltages for the DP+ and DP- (data lines
+/-)? Speaking of data lines, I noticed some of my cords will not
transfer data and can only be used for charging. The thicker cord I was
using does have the ability to transfer data so I'm wondering if there's
some kind of communication going on between the charger and the Kindle
that affects the charging rate.

[legg]

<snip>

>things were progressing so I stopped monitoring the charging current.
>
>In summary, it's a nice tool to use but the owner's manual...
>
>https://drive.google.com/file/d/1ZFC9TEPUBI5vD081lVSdVgsmeWRnaqi9/view?usp=sharing

1/2G Zip file?

>
>...takes some time to absorb as it's apparently been translated from
>another language. Maybe one of you could explain the importance (or
>unimportance) in knowing the voltages for the DP+ and DP- (data lines
>+/-)? Speaking of data lines, I noticed some of my cords will not
>transfer data and can only be used for charging. The thicker cord I was
>using does have the ability to transfer data so I'm wondering if there's
>some kind of communication going on between the charger and the Kindle
>that affects the charging rate.
>
>Thanks for your reply.

You have to install National Instruments VISA package, Microsoft
Studio, Labview elements yada yada and 2Meg worth of licensing
agreements to use a $22 USB power test dongle?

Depending on how you look at it, it's either the deal of the
century or some kind of OS invasion.

RL

[Peter W.]

> You have to install National Instruments VISA package, Microsoft
> Studio, Labview elements yada yada and 2Meg worth of licensing
> agreements to use a $22 USB power test dongle?

a) Does it charge the device? - Yes. Stop there.
b) Does it charge the device? - No. Not at all? Replace. Yes but exceedingly slowly.
c) Exceedingly slowly - Will another charger charge the device? Yes - dispose of first charger. No - suspect the device.

This is not rocket science, nor is it worth any sort of brain damage, deep analysis or heroic measures. But, then this venue exists to provide overly complex solutions to simple problems after extensive discussions of picayune and irrelevant issues.

[Jeff Liebermann]

On Sun, 27 Feb 2022 08:57:19 -0500, legg <le...@nospam.magma.ca> wrote:

>>In summary, it's a nice tool to use but the owner's manual...
>>
>>https://drive.google.com/file/d/1ZFC9TEPUBI5vD081lVSdVgsmeWRnaqi9/view?usp=sharing

>1/2G Zip file?

473MB ZIP file which un-compresses to 570MB. 386 files,

The reason for the absurdly large file size is that the AC3 PC
Software v1.3 appears twice in the ZIP archive. Once as uncompressed
files and again as a RAR archive.

For those interested, I copied the device and PC software instructions
to:
<http://www.learnbydestroying.com/jeffl/A3C-USB-Analyzer/>
About 2MBytes total.

Note that all this ignores the original problem of charging the
Kindle, which I guessed was because the 5V charger was rated at less
than the required 2 Amps. It also appears that there's a USB cable
problem which might be attributable to excessively high DC resistance
or possibly the lack of data wires needed to negotiate a USB charging
protocol.

I'll play with this when time permits. Busy with firewood and dump
runs for a few days.