Advice sought on why 6.8A USB charger melted USB cable today

[Danny D.]

I would just like some advice since I melted a USB cable today
and I realized I don't have the proper troubleshooting skills.

I bought over a half-dozen "Hype Volt" 6.8Amp USB chargers for
stuffing the Christmas stockings:
https://i.imgur.com/Zavgm4B.jpg

I kept one for myself, but, when I used it last night on an iPad
and on an Android phone, the iPad lightning cable melted!

When I pulled it off the iPad, it was noticeably extremely hot,
but it doesn't seem to have damaged the iPad (AFAIK).

So, I'm just wondering what happened, and, more importantly, when
I look at the specs for this device, they don't make sense to me,
so, I have difficulty troubleshooting what the problem is/was.

Here are all the specs off the package and off the device:
DGL Group Ltd. Hype Volt HV-6PT
Model: HC363-5U (also listed as HV-6PT-WHT)
Input: AC 110VAC/60Hz - 220VAC/50Hz (800mA max)
Output: DC 5V, 6.8A total
Maximum Power: 40W
Supercharge: 5...@2.4A maximum
Universal: 5V@1A maximum

Description:
http://www.amazon.com/Hype-Compact-Automatically-Adjustable-Adapter/dp/B00T3FQBHO
http://www.walmart.ca/en/ip/hype-volt-68a-wall-adapter-with-5-usb-ports/6000193376994

My questions are varied, because I don't understand how it works,
nor how it could have overheated the cable to the tablet.

Here's what it says on the package:
"Smart USB Technology: This adapter automatically adjusts power
output to fit your charging device. Tablets and e-readers require
2 Amp charging, and this adapter will reroute power to the
appropriate USB port you use."

"Charging Combinations:
- 2 tablets + 3 mobile devices
- 1 tablet + 4 mobile devices
- 5 mobile devices
- 3 tablets"

I am confused about both the pure math and how this operates.

Q1: Since 6.8A times 5VDC is only 34Watts (not 40 Watts), how
can they very clearly label it as a 40Watt device?

Q2: How does the device "know" to give tablets 2.4 Amps
(12 Watts) but a "mobile device" only 1Amp (5 Watts).

Q3: What if a mobile device "wants" more than 1 amp?
Does the charger give more than 1A to the device?

[M Philbrook]

In article <n3hvfl$3ud$1...@dont-email.me>, dannyd...@gmail.com says...

> "Charging Combinations:
> - 2 tablets + 3 mobile devices
> - 1 tablet + 4 mobile devices
> - 5 mobile devices
> - 3 tablets"
>
> I am confused about both the pure math and how this operates.
>
> Q1: Since 6.8A times 5VDC is only 34Watts (not 40 Watts), how
> can they very clearly label it as a 40Watt device?

Yes, the supply/charger is using a total of 40 watts, some of which
gets lost with in itself the remainder used for the connected devices.
One could say it's 85% efficient.

>
> Q2: How does the device "know" to give tablets 2.4 Amps
> (12 Watts) but a "mobile device" only 1Amp (5 Watts).
>
> Q3: What if a mobile device "wants" more than 1 amp?
> Does the charger give more than 1A to the device?
>

Many devices can link up to things like PCs. The USB port
has more than just power/charging wires. They also have
data wires.

Its posible the charger could be detecting basics about the
device and selecting a current via the data lines.

On devices that it can't determine the ratings, it may
deside to give it all!.

Jamie

[Danny D.]

M Philbrook wrote, on Mon, 30 Nov 2015 15:18:19 -0500:

>> Q1: Since 6.8A times 5VDC is only 34Watts (not 40 Watts), how
>> can they very clearly label it as a 40Watt device?
> Yes, the supply/charger is using a total of 40 watts, some of which
> gets lost with in itself the remainder used for the connected devices.
> One could say it's 85% efficient.

While the *input* wattage could be 40Watts, given the input voltage
and maximum input current, the *input* is something like 80VA:
https://i.imgur.com/8bl7ypU.jpg

That's 100-240VAC (RMS) times 800mA, which is about 80VA.

If the package wanted to say it was input power, it would have stated
the 40 as 40VA and not 40W, wouldn't it?
https://i.imgur.com/30qxupn.jpg

So it's only about 50% efficient if we believe that the max input power
dissipation is 80VA while the max output power is 40W.

The 40 Watts listed on the package doesn't match either the input
volt-amperes nor the output wattage calculated from the specs off
the device itself.

This description has the same discrepancy:
https://www.touchofmodern.com/sales/hype-volt/smart-adapter

I called the company that makes the product but only could speak with
sales who didn't know what the reason for the discrepancy was:
http://listings.findthecompany.com/l/8916005/DGL-Group-Ltd-in-Edison-NJ
195 Raritan Center Pkwy
Edison, New Jersey 08837-3650
(718) 499-1000
http://www.dglusa.com

So, I'm still left with 40 Watts listed on the package, while no
numbers listed on the device for either input volt-amperes or
output watts is anywhere near that number.

[Ian Field]

"Danny D." <dannyd...@gmail.com> wrote in message
news:n3hvfl$3ud$1...@dont-email.me...

> I would just like some advice since I melted a USB cable today
> and I realized I don't have the proper troubleshooting skills.
>
> I bought over a half-dozen "Hype Volt" 6.8Amp USB chargers for
> stuffing the Christmas stockings:
> https://i.imgur.com/Zavgm4B.jpg
>
> I kept one for myself, but, when I used it last night on an iPad
> and on an Android phone, the iPad lightning cable melted!
>
> When I pulled it off the iPad, it was noticeably extremely hot,
> but it doesn't seem to have damaged the iPad (AFAIK).

The official spec for USB says its limited to 500mA at 5V.

As long as the 5V is rock steady and within spec the current draw should be
whatever the appliance normally takes.

The highest I've seen offered for sale was 2.1A.

You should probably get them checked out before you burn down anyone's
Christmas tree.

[Danny D.]

Ian Field wrote, on Mon, 30 Nov 2015 21:40:17 +0000:

> The official spec for USB says its limited to 500mA at 5V.

That's old information.
Here is newer information:
http://www.extremetech.com/computing/115251-how-usb-charging-works-or-how-to-avoid-blowing-up-your-smartphone
How USB charging works, or how to avoid blowing up your smartphone

The article says there are three types of USB 3.0 ports:
1. Standard downstream port (900mA at 5VDC = 4.5Watts)
2. Charging downstream port (1.5A at 5VDC = 7.5Watts)
3. Dedicated charging port (1.5A at 5VDC = 7.5Watts)

In addition, tablet-charging USB ports typically are 2.1 Amp
minimum, and some are as high as 2.4 Amps per port like this
charger says it is.

The problem I have is that it says it's 40Watts, which it
can't be if it's also limited to 6.8 Amps per port for 5
ports.

[Ian Field]

"Danny D." <dannyd...@gmail.com> wrote in message

news:n3ig9e$a9v$2...@dont-email.me...

> Ian Field wrote, on Mon, 30 Nov 2015 21:40:17 +0000:
>
>> The official spec for USB says its limited to 500mA at 5V.
>
> That's old information.
> Here is newer information:
> http://www.extremetech.com/computing/115251-how-usb-charging-works-or-how-to-avoid-blowing-up-your-smartphone
> How USB charging works, or how to avoid blowing up your smartphone

I guess it boils down to how badly you want to ruin peoples Christmas.

If the one you tried melted the USB cable and overheated the appliance,
something is clearly wrong.

[M Philbrook]

In article <n3ie7f$1ce$2...@dont-email.me>, dannyd...@gmail.com says...

Being experienced with such electronics, most of the designs out there
do not specify inrush currents over normal. It's better to specify the
max it could be at, even if only in milSec.

Completely drained capacitors in the input can cause an inrush while
charging for the initial on cycle, but the rating on the input does not
mean it will remain there. Most of those things have a form of time
delay fuse and thermal resistor that will help with the inital start.

I did the math and from my point of view, it looks correct.

I don't know where all this is leading to but, I beginning to think it
has more to do with just being unhappy due to package confusing.

P.S.
I don't think they will be replacing your charging cord or tablet..

Jamie

[Micky]

On Mon, 30 Nov 2015 17:02:46 -0000 (UTC), "Danny D."
<dannyd...@gmail.com> wrote:

>I would just like some advice since I melted a USB cable today
>and I realized I don't have the proper troubleshooting skills.
>
>I bought over a half-dozen "Hype Volt" 6.8Amp USB chargers for
>stuffing the Christmas stockings:
> https://i.imgur.com/Zavgm4B.jpg

It seems to have melted some plastic or rubber.

Can you still use the cable?

Isn't the better goal to be figuring out why it overheated so maybe
you can continue to ucse the charger, if possible?

Maybe there was a bad connection at that USB connector. Bad
connections generate heat, though in practice , I've only seen that at
a plug/receptacle connection for a 1100 watt room heater (where a
40-year old receptacle made the plug so hot the hard-rubber plug
caught on fire) and a car battery/battery cable junction that was
powering a whole car (minus the alternator, which should have been
plenty so that's confusing) which was hot to the touch and that's how
I realized it was loose.

I can't really imagine this happening on 5 volts, but then again, it
did. I think it was a bad connection even though the amperage was
within range.

I don't think a good connection would generate any noticeable heat
even if it was putting out twice the proper amperage.

[Danny D.]

M Philbrook wrote, on Mon, 30 Nov 2015 17:08:19 -0500:

> I did the math and from my point of view, it looks correct.

You make a fair enough point of where things are going, which,
for this issue, is simply to *understand* what is happening.

I think the melted cable is merely a bad cable (with a low
resistance short between internal wires perhaps).

I don't (yet) understand the 40Watts of "power".

Going only by the printed specs, if that 40W is stating the
input power, wouldn't that be double that (at 100VAC rms times
800mA rms)?

And, if the 40W is output power, there's no way that 5VCD times
6.8Amps is anywhere near 40W (it's 15% less, which is a lot).

So, if your numbers matched the 40Watts (whether that's input
power dissipation or output power), if you show the math, it
would be better understood by me.

[Danny D.]

Ian Field wrote, on Mon, 30 Nov 2015 22:05:26 +0000:

> If the one you tried melted the USB cable and overheated the appliance,
> something is clearly wrong.

I think the cable was bad, because it's rare for a charger to
put out *more* than the 2.4Amps that it says a port can output.

But that doesn't help explain where the 40Watts comes from since
no calculation comes close, whether that's input RMS VA or output
Watts.

[Danny D.]

Micky wrote, on Mon, 30 Nov 2015 18:32:49 -0500:

> Isn't the better goal to be figuring out why it overheated so maybe
> you can continue to ucse the charger, if possible?

This is a very fair perspective, especially since I have a half
dozen of these 6.8Amp five-port USB chargers (they were on sale for
less than $20 each).

I ran down the iPad all morning, by running GPS software and Youtube
videos and I put it on a permanent Hangouts video conference call
so that the battery ran down to something like 50%.

I then put the iPad on the same charger with a *different* cable,
and, so far, the ipad is about at 75% and the (different) cable
is *not* overheating yet.

So, at this point, if the iPad charges overnight with the different
cable without overheating, I think I would have to conclude it's not
a good cable.

I'll know by tomorrow.

[Danny D.]

Micky wrote, on Mon, 30 Nov 2015 18:32:49 -0500:

> I don't think a good connection would generate any noticeable heat
> even if it was putting out twice the proper amperage.

This is a good point. So, I'm assuming the cable is bad and I switched
cables and at the moment, there is no heat.

As for the 40Watt figure, I think it's a lie because I googled
for the part number that is printed on the side of the unit:
https://i.imgur.com/8bl7ypU.jpg

Notice that HC363-5U printed on the unit?

Googling for just that, I find the same unit only with a different
set of markings, which is listed as being 35Watts, which is closer
to the 34 Watts that 6.8 Amps gets us at 5 VDC:
http://www.amazon.com/Hausbell-35W-HC363-5U-Certified-Family-Sized/dp/B00NUREFMO
"Hausbell 35W HC363-5U UL Certified (UL No:E310745)
Family-Sized USB Wall Charger Plug Smart Charger,
Single USB Output 2.4A Max,Output total 6.8A Max,5P-USB Output
for Apple and Android Smartphones,Tablets and More(White)
by Hausbell, Price: $59.99 & FREE Shipping"

Here's the same unit, this time for $15 but it also calls it 35 Watts:
http://www.amazon.com/Hausbell-Charger-Certified-Foldable-Smartphones/dp/B00ORLR1X2

Here's another, again listing it as 35Watts:
http://www.sportinggoodsoutdoor.com/p/detail/B00ORLR1X2/Pre-sale-promotionHausBell-35W-HC363-5U-UL-Certified-UL-NoE310745-Family-Sized-USB-Wall-Charger-Plug-Smart-ChargerSingle-USB-Output-24A-MaxOutput-total-68A-Max5P-USB-Output-for-Apple-and.html

And another listing it as 35 Watts:
http://hausbell.net/products/cell-phones-accessories/travel-chargers/family-sized-usb-wall-charger-5p-usb-output-238.html

And another listing it as 35Watts:
http://macbookpro.deal2hand.com/review-Hausbell-35W-5-Port-USB-Wall-Charger-UL-Certified-with-Foldable-Plug-for-Apple-and-Android-Smartphones-Table_B00ORLR1X2.html

So, pretty much, the 40Watts is either a bold-faced lie, or it's
not the wattage of the output (which is closer to 34 Watts).

[jurb...@gmail.com]

First of all, to melt a wire or connector, there must be an overload. Unless the charger went overvoltage it is not at fault. check what you were charging and its cable.

[Danny D.]

Even if the charger put out all 6.8 Amps into the iPad, there shouldn't
have been resistance AT the cable end sufficient to cause the cable
plastic to melt from the power dissipation at the connection point.

So, that pretty much tells me that the cable was bad. It could have
started a fire, so, it's good that I pulled that cable out of service.

I have the same charger and a different cable, so I will see if this
second cable (this one is from Staples, I think, instead of from
Office Max) works without overheating.

[Micky]

On Tue, 1 Dec 2015 00:40:52 -0000 (UTC), "Danny D."
<dannyd...@gmail.com> wrote:

>Micky wrote, on Mon, 30 Nov 2015 18:32:49 -0500:
>
>> I don't think a good connection would generate any noticeable heat
>> even if it was putting out twice the proper amperage.
>
>This is a good point.

If you keep being nice to the people you deal with on Usenet, it will
be hard to fight with you. For many people that will ruin the whole
experience.

> So, I'm assuming the cable is bad and I switched
>cables and at the moment, there is no heat.
>
>As for the 40Watt figure, I think it's a lie because I googled

I don't know why this bothers you so much. Maybe it is a lie, they
were trying to increase sales. Maybe the guy who said 40 was drunk,
but he really thought it was 40. Maybe he made an error. Do you
remember the Hubble telescope? 100's of millions of dollars and they
ground the mirror wrong because someone miscalculated. If they can do
it, so can whoever made the charger.

Based on what you have below, it's probably 35 watts.

[Danny D.]

Micky wrote, on Tue, 01 Dec 2015 00:12:10 -0500:

> Based on what you have below, it's probably 35 watts.

Nobody makes that kind of mistake by accident.
The difference between 34 Watts and 40 Watts is huge.

I suspect they wanted to compete with the competitor who makes the
exact same device (same everything but the name and the lie on the
package).

I do have a call in to the manufacturer to find out why they say
40 Watts, and I will report it to Consumer Reports if I can find
an email address to do so.

[Ian Field]

"Danny D." <dannyd...@gmail.com> wrote in message

news:n3ioje$bem$3...@dont-email.me...

> Ian Field wrote, on Mon, 30 Nov 2015 22:05:26 +0000:
>
>> If the one you tried melted the USB cable and overheated the appliance,
>> something is clearly wrong.
>
> I think the cable was bad, because it's rare for a charger to
> put out *more* than the 2.4Amps that it says a port can output.

Had you considered it might be putting out more than the 5V its supposed to?

[Ian Field]

"Micky" <NONONO...@bigfoot.com> wrote in message
news:4pmp5bdkr6af6ddlr...@4ax.com...

> On Mon, 30 Nov 2015 17:02:46 -0000 (UTC), "Danny D."
> <dannyd...@gmail.com> wrote:
>
>>I would just like some advice since I melted a USB cable today
>>and I realized I don't have the proper troubleshooting skills.
>>
>>I bought over a half-dozen "Hype Volt" 6.8Amp USB chargers for
>>stuffing the Christmas stockings:
>> https://i.imgur.com/Zavgm4B.jpg
>
> It seems to have melted some plastic or rubber.
>
> Can you still use the cable?
>
> Isn't the better goal to be figuring out why it overheated so maybe
> you can continue to ucse the charger, if possible?

Apparently; the OP bought over half-dozen of these units for stocking
fillers.

Probably worth figuring out what the problem is before one wrecks the nice
shiny pad someone got for Christmas - or burns down their Christmas
tree...................

[Ian Field]

<jurb...@gmail.com> wrote in message
news:0b30ab1b-af56-41ac...@googlegroups.com...

> First of all, to melt a wire or connector, there must be an overload.
> Unless the charger went overvoltage it is not at fault. check what you
> were charging and its cable.

To quote a paragraph from the OP;

"When I pulled it off the iPad, it was noticeably extremely hot,
but it doesn't seem to have damaged the iPad (AFAIK)."

Seems to indicate the iPad was working (and apparently undamaged) - and
since the device got hot, a short in the cable isn't that likely.

Maybe mis-wired cable reversing the polarity, or regulation fault in the
charger.

[Danny D.]

Ian Field wrote, on Tue, 01 Dec 2015 18:29:45 +0000:

> Had you considered it might be putting out more than the 5V its supposed to?

It could be.
What I need is one of those USB DMM tester cables that Jeff keeps recommending.

[Danny D.]

Ian Field wrote, on Tue, 01 Dec 2015 18:32:51 +0000:

> Probably worth figuring out what the problem is before one wrecks the nice
> shiny pad someone got for Christmas - or burns down their Christmas
> tree

I tested it with another cable but same charger and iPad overnight.
It didn't get hot.

So, I think it's the cable.

[pf...@aol.com]

Possibly, even likely, that "it's the cable". But the lesson to be leaned is that if one in six is bad, that is a pretty wretched record. And whether at 5V or 50V, 5 amps is a considerable amount of current that *will* melt fine wire if shorted. So, poor quality control is a real concern. Are the remaining five ticking bombs, or are you *sure* it is just this one cable?

Put another way, you get what you pay for.

Put yet another way, do not rely on your equipment to protect itself from a bad peripheral.

I could purchase a Rolex watch when we were in China for US$5. It said so right on the watch!!

Peter Wieck
Melrose Park, PA

[jf...@my-deja.com]

On Wednesday, December 2, 2015 at 3:56:09 AM UTC-8, pf...@aol.com wrote:
> I could purchase a Rolex watch when we were in China for US$5.
> It said so right on the watch!!
>
> Peter Wieck
> Melrose Park, PA

The amazing thing is that it does a much better job of keeping time than a real Rolex, with a typical error of about 1-2 seconds/month.