Looking to get a couple as they look to be useful.
Probably missed the extra long discussion that someone is going to point
me to But, what are the residents opinions on these?

If they are all certified up then I guess they must be safe, but I don't
know, something about them just nags at me...

On 08/10/2014 13:22, Lee wrote:
Looking to get a couple as they look to be useful.
Probably missed the extra long discussion that someone is going to point
me to But, what are the residents opinions on these?

If they are all certified up then I guess they must be safe, but I don't
know, something about them just nags at me...

Obsolescence? How much longer is USB going to last? And you need to make
sure they can give enough current, as some tablets now need to draw in
excess of 2 amps.

I'd also be a bit annoyed at having to grovel round near floor level to
charge my phone. My current (4 output) USB charger is mounted on the
desk top, and when the standards grow out of it or it breaks, I just
need to unplug it and replace it, rather than killing power to the ring,
stripping out a wall socket, replacing it and checking it's safe.

--
Tciao for Now!

John.

On 08/10/14 13:22, Lee wrote:
Looking to get a couple as they look to be useful.
Probably missed the extra long discussion that someone is going to point
me to But, what are the residents opinions on these?

If they are all certified up then I guess they must be safe, but I don't
know, something about them just nags at me...

I would not bother.

The spec keeps going up in terms of charging current and every couple of
years I end up with a whole new set of ada

What might be good would be a multi-point (say 3-4) 13A PSU adaptor.
Must look out for one.

On Wed, 08 Oct 2014 13:22:05 +0100, Lee
wrote:

Looking to get a couple as they look to be useful.
Probably missed the extra long discussion that someone is going to point
me to But, what are the residents opinions on these?

Some people here don't like them and say so forcefully. I can't see
that USB charging requirements are going to change that much, if at
all, to make the obsolete in the short term.
I have one with 2a outputs (one of these:
http://www.mobilefun.co.uk/encharge-...ite-p45980.htm
- there are others) and find it satisfactory. I don't have to keep
fiddling around on the floor because I leave a pair of USB leads
connected to it, and I have a four-way adapter in my overnight bag.

Well, I don't like them as they are not always current limited. I don't like
usb wall warts either.
I know a person who trashed their mp3 player charging this way, over cooked
the battery.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Lee" wrote in message
...
Looking to get a couple as they look to be useful.
Probably missed the extra long discussion that someone is going to point
me to But, what are the residents opinions on these?

If they are all certified up then I guess they must be safe, but I don't
know, something about them just nags at me...

I don't thin usb as a standard will go away in the next decade, as so many
things now use it, but interesting about you having the opposite current
issues to those i have.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"John Williamson" wrote in message
...
On 08/10/2014 13:22, Lee wrote:
Looking to get a couple as they look to be useful.
Probably missed the extra long discussion that someone is going to point
me to But, what are the residents opinions on these?

If they are all certified up then I guess they must be safe, but I don't
know, something about them just nags at me...

Obsolescence? How much longer is USB going to last? And you need to make
sure they can give enough current, as some tablets now need to draw in
excess of 2 amps.

I'd also be a bit annoyed at having to grovel round near floor level to
charge my phone. My current (4 output) USB charger is mounted on the desk
top, and when the standards grow out of it or it breaks, I just need to
unplug it and replace it, rather than killing power to the ring, stripping
out a wall socket, replacing it and checking it's safe.

--
Tciao for Now!

John.

On 08/10/2014 13:22, Lee wrote:
Looking to get a couple as they look to be useful.
Probably missed the extra long discussion that someone is going to point
me to But, what are the residents opinions on these?

If they are all certified up then I guess they must be safe, but I don't
know, something about them just nags at me...

As others have said, increasing current demands of newer equipment may
make the existing current limit a bit lacking in the near future.

Presumably always on, altough their power demands will be very low when
unused.

pedant mode
They are not chargers, but 5V (ish) power supplies that can supply a
current up to 1 or 2 amps.
The charging circuitry is built in to the device (phone, tablet , etc)
that is connected.
/pedant mode

You would be better purchasing some of these:

https://www.modmypi.com/5v-2A-modmyp...i-power-supply

On 08/10/2014 15:55, Peter Johnson wrote:
On Wed, 08 Oct 2014 13:22:05 +0100, Lee
wrote:

Looking to get a couple as they look to be useful.
Probably missed the extra long discussion that someone is going to point
me to But, what are the residents opinions on these?

Some people here don't like them and say so forcefully. I can't see
that USB charging requirements are going to change that much, if at
all, to make the obsolete in the short term.
I have one with 2a outputs (one of these:
http://www.mobilefun.co.uk/encharge-...ite-p45980.htm
- there are others) and find it satisfactory. I don't have to keep
fiddling around on the floor because I leave a pair of USB leads
connected to it, and I have a four-way adapter in my overnight bag.

If this helps, this link sells them much cheaper:
http://www.saverstore.com/product/20...Charging-Ports

On 08/10/2014 15:56, Brian Gaff wrote:

Brian, any device will only draw the current it needs, as far as I know.


Well, I don't like them as they are not always current limited. I don't like
usb wall warts either.
I know a person who trashed their mp3 player charging this way, over cooked
the battery.
Brian

On Wednesday, October 8, 2014 4:10:15 PM UTC+1, Rob wrote:
On 08/10/2014 13:22, Lee wrote:

Looking to get a couple as they look to be useful.
Probably missed the extra long discussion that someone is going to point
me to But, what are the residents opinions on these?

If they are all certified up then I guess they must be safe, but I don't
know, something about them just nags at me...

As others have said, increasing current demands of newer equipment may
make the existing current limit a bit lacking in the near future.

I expect there will be another iteration of usb having an extra pin that enables higher V_out too.


Presumably always on, altough their power demands will be very low when
unused.

Yes, to the point of trivial now.


No-one's mentioned yet the proliferation of unsafe warts, be a bit careful what you buy or inuslation test it.


NT

In message , Rob
writes
On 08/10/2014 13:22, Lee wrote:
Looking to get a couple as they look to be useful.
Probably missed the extra long discussion that someone is going to point
me to But, what are the residents opinions on these?

If they are all certified up then I guess they must be safe, but I don't
know, something about them just nags at me...

As others have said, increasing current demands of newer equipment may
make the existing current limit a bit lacking in the near future.

Probably, but there presumably is a limit to what the usb connector will
handle?


Presumably always on, altough their power demands will be very low when
unused.

Yeah, not really worth worrying about, our usb walwarts generally are
left plugged in and switched on, the draw nothing much

pedant mode
They are not chargers, but 5V (ish) power supplies that can supply a
current up to 1 or 2 amps.
The charging circuitry is built in to the device (phone, tablet , etc)
that is connected.
/pedant mode

You would be better purchasing some of these:

https://www.modmypi.com/5v-2A-modmyp...i-power-supply

Fine, but the USB plug is on the bottom, which I generally find
annoying, and couple of outputs is useful

--
Chris French

In message ,
writes
On Wednesday, October 8, 2014 4:10:15 PM UTC+1, Rob wrote:
On 08/10/2014 13:22, Lee wrote:

Looking to get a couple as they look to be useful.
Probably missed the extra long discussion that someone is going to point
me to But, what are the residents opinions on these?

If they are all certified up then I guess they must be safe, but I don't
know, something about them just nags at me...

As others have said, increasing current demands of newer equipment may
make the existing current limit a bit lacking in the near future.

I expect there will be another iteration of usb having an extra pin
that enables higher V_out too.


USB3 is already designed to supply a higher current than the standard
usb 500ma, but I'm not sure what it is. Don't think it is as high as the
2+ A supplied by some USB chargers.



Presumably always on, altough their power demands will be very low when
unused.

Yes, to the point of trivial now.



No-one's mentioned yet the proliferation of unsafe warts, be a bit
careful what you buy or inuslation test it.


Hard though sometimes, when even reputable products may be cheap copies.

I have though found an extension lead with a couple of built in USB
ports useful (mine is a Masterplug unit with 4 13A outlets as well).

One advantage of, the built in usb outlets is that you can take the
walwart away somewhere else :-)

NT

--
Chris French

On 08/10/2014 18:12, Bod wrote:
On 08/10/2014 15:56, Brian Gaff wrote:

Brian, any device will only draw the current it needs, as far as I know.


Well, I don't like them as they are not always current limited. I
don't like
usb wall warts either.
I know a person who trashed their mp3 player charging this way, over
cooked
the battery.
Brian


Oh dear.

Peter Johnson wrote
Lee wrote

Looking to get a couple as they look to be useful.

Probably missed the extra long discussion that someone is going
to point me to But, what are the residents opinions on these?

Some people here don't like them and say so forcefully. I can't
see that USB charging requirements are going to change that
much, if at all, to make the obsolete in the short term.

They are in fact changing at one hell of a rate currently.
http://en.wikipedia.org/wiki/USB#Power

I have one with 2a outputs (one of these:
http://www.mobilefun.co.uk/encharge-...ite-p45980.htm
- there are others) and find it satisfactory. I don't have to keep
fiddling around on the floor because I leave a pair of USB leads
connected to it, and I have a four-way adapter in my overnight bag.

On 08/10/2014 18:12, Bod wrote:
On 08/10/2014 15:56, Brian Gaff wrote:

Brian, any device will only draw the current it needs, as far as I know.

That isn't necessarily true. Any well designed device will only take
what it needs and then feather the charge current to zero.

A badly designed device will keep taking current until either it
overheats and vents the battery or the battery catches fire depending on
the precise battery technology being used.

Polite devices are supposed to ask the OS to enable high current mode
but some just grab without asking and that can cause trouble sometimes.

Well, I don't like them as they are not always current limited. I
don't like
usb wall warts either.
I know a person who trashed their mp3 player charging this way, over
cooked
the battery.
Brian

Most are short circuit protected and will give very little more than
their nominal maximum output. The problem lies with devices that assume
that the maximum output is 1A (or worse 0.5A) when there are now 2A
units about. Naive older devices can get cooked this way.

I already have more than enough wallwart ones and seldom need more than
two in use at a time. I can't see the point in having one in the wall.

At least now they all give the same voltage and a common connector. The
previous mobile phone and laptop charger wars led to a proliferation of
random voltages, currents and ever more weird connectors.

I doubt that USB charge currents will go up too much more as the present
value is close to the limits for the connectors to be reliable.

--
Regards,
Martin Brown

In article ,
Martin Brown wrote:
On 08/10/2014 18:12, Bod wrote:
On 08/10/2014 15:56, Brian Gaff wrote:

Brian, any device will only draw the current it needs, as far as I know.

That isn't necessarily true. Any well designed device will only take
what it needs and then feather the charge current to zero.

A badly designed device will keep taking current until either it
overheats and vents the battery or the battery catches fire depending on
the precise battery technology being used.

Polite devices are supposed to ask the OS to enable high current mode
but some just grab without asking and that can cause trouble sometimes.

Well, I don't like them as they are not always current limited. I
don't like
usb wall warts either.
I know a person who trashed their mp3 player charging this way, over
cooked
the battery.
Brian

Most are short circuit protected and will give very little more than
their nominal maximum output. The problem lies with devices that assume
that the maximum output is 1A (or worse 0.5A) when there are now 2A
units about. Naive older devices can get cooked this way.

I already have more than enough wallwart ones and seldom need more than
two in use at a time. I can't see the point in having one in the wall.

At least now they all give the same voltage and a common connector. The
previous mobile phone and laptop charger wars led to a proliferation of
random voltages, currents and ever more weird connectors.

I doubt that USB charge currents will go up too much more as the present
value is close to the limits for the connectors to be reliable.

what has such a technical limit got to do with anything?

--
From KT24

Using a RISC OS computer running v5.18

On 09/10/2014 09:16, Martin Brown wrote:
On 08/10/2014 18:12, Bod wrote:
On 08/10/2014 15:56, Brian Gaff wrote:

Brian, any device will only draw the current it needs, as far as I know.

That isn't necessarily true. Any well designed device will only take
what it needs and then feather the charge current to zero.

A badly designed device will keep taking current until either it
overheats and vents the battery or the battery catches fire depending on
the precise battery technology being used.

Polite devices are supposed to ask the OS to enable high current mode
but some just grab without asking and that can cause trouble sometimes.

Well, I don't like them as they are not always current limited. I
don't like
usb wall warts either.
I know a person who trashed their mp3 player charging this way, over
cooked
the battery.
Brian

Most are short circuit protected and will give very little more than
their nominal maximum output. The problem lies with devices that assume
that the maximum output is 1A (or worse 0.5A) when there are now 2A
units about. Naive older devices can get cooked this way.

I already have more than enough wallwart ones and seldom need more than
two in use at a time. I can't see the point in having one in the wall.

At least now they all give the same voltage and a common connector. The
previous mobile phone and laptop charger wars led to a proliferation of
random voltages, currents and ever more weird connectors.

I doubt that USB charge currents will go up too much more as the present
value is close to the limits for the connectors to be reliable.

If the device being charged is designed for a 1 amp charger, then using
a 2 amp will simply charge up quicker. I have used 2 amp chargers for
years with all of my devices, even the ones that were supplied with 1
amp chargers. I've never had any problems.

On 09/10/14 09:27, Bod wrote:

If the device being charged is designed for a 1 amp charger, then using
a 2 amp will simply charge up quicker. I have used 2 amp chargers for
years with all of my devices, even the ones that were supplied with 1
amp chargers. I've never had any problems.

Not entirely - anything with a lithium based battery is supposed to
regulate its charging and discharging as going out of bounds in either
direction is dangerous (fire risk).

On 09/10/2014 09:50, Tim Watts wrote:
On 09/10/14 09:27, Bod wrote:

If the device being charged is designed for a 1 amp charger, then using
a 2 amp will simply charge up quicker. I have used 2 amp chargers for
years with all of my devices, even the ones that were supplied with 1
amp chargers. I've never had any problems.

Not entirely - anything with a lithium based battery is supposed to
regulate its charging and discharging as going out of bounds in either
direction is dangerous (fire risk).

It doesn't mention anything about that in this article:

"The micro USB connector has become the de-facto standard, used by
almost everyone except Apple, so you only need to take one charger with
you. Most chargers will work on any mains supply, from 100 to 240 volts
AC 50/60Hz and the output is a standard 5 volts DC, but the current they
can deliver does vary, and may be insufficient to charge some devices.
The solution is to pack the charger with the highest rated output. This
will be printed on the case and is typically between 500mA (milliamps)
and 2.5 amps.

http://www.telegraph.co.uk/technolog...y-gadgets.html

On 09/10/2014 10:01, Bod wrote:
On 09/10/2014 09:50, Tim Watts wrote:
On 09/10/14 09:27, Bod wrote:

If the device being charged is designed for a 1 amp charger, then using
a 2 amp will simply charge up quicker. I have used 2 amp chargers for
years with all of my devices, even the ones that were supplied with 1
amp chargers. I've never had any problems.

Not entirely - anything with a lithium based battery is supposed to
regulate its charging and discharging as going out of bounds in either
direction is dangerous (fire risk).

It doesn't mention anything about that in this article:

"The micro USB connector has become the de-facto standard, used by
almost everyone except Apple, so you only need to take one charger with
you. Most chargers will work on any mains supply, from 100 to 240 volts
AC 50/60Hz and the output is a standard 5 volts DC, but the current they
can deliver does vary, and may be insufficient to charge some devices.
The solution is to pack the charger with the highest rated output. This
will be printed on the case and is typically between 500mA (milliamps)
and 2.5 amps.

http://www.telegraph.co.uk/technolog...y-gadgets.html

This article also agrees with what I'm saying:

"You might think that all chargers are created equally, but nothing
could be further from the truth. Wired explains that picking the right
charger with the right amperage (a measure of current) can mean the
difference between getting your phone charged while you work versus
waiting all day before you can unplug it.

This isn't as simple as just "charge your device with the charger it
shipped with." You can actually use higher amperage chargers, like the
kind that come with tablets, to get your phone charged up in less time
than it would if you charged via USB or using the charger the phone came
with, and it won't cause a problem. Here's how it breaks down"

http://lifehacker.com/pay-attention-...adg-1492446246

Chris French wrote:

USB3 is already designed to supply a higher current than the standard
usb 500ma, but I'm not sure what it is. Don't think it is as high as the
2+ A supplied by some USB chargers.

USB3.1 will allow up to 2A at 5V and optionally 5A at 12V or 20V.

On 09/10/2014 10:17, Bod wrote:
On 09/10/2014 10:01, Bod wrote:
On 09/10/2014 09:50, Tim Watts wrote:
On 09/10/14 09:27, Bod wrote:

If the device being charged is designed for a 1 amp charger, then using
a 2 amp will simply charge up quicker. I have used 2 amp chargers for
years with all of my devices, even the ones that were supplied with 1
amp chargers. I've never had any problems.

Not entirely - anything with a lithium based battery is supposed to
regulate its charging and discharging as going out of bounds in either
direction is dangerous (fire risk).

It doesn't mention anything about that in this article:

"The micro USB connector has become the de-facto standard, used by
almost everyone except Apple, so you only need to take one charger with
you. Most chargers will work on any mains supply, from 100 to 240 volts
AC 50/60Hz and the output is a standard 5 volts DC, but the current they
can deliver does vary, and may be insufficient to charge some devices.
The solution is to pack the charger with the highest rated output. This
will be printed on the case and is typically between 500mA (milliamps)
and 2.5 amps.

http://www.telegraph.co.uk/technolog...y-gadgets.html

Relying on the Telegraph for technology advice is unwise, but you have
evidently found some even more unreliable dross "advice" to quote below.

Here is something reasonably accessible about charging NiMH:

http://www.powerstream.com/NiMH.htm

And a slightly more technical one about charging Lithium ion:

http://batteryuniversity.com/learn/a..._ion_batteries

The higher rated charger will work OK with most things but some older
kit that assumes that it will never see more than 500mA USB supply
current could react badly to having 2A available.


This article also agrees with what I'm saying:

"You might think that all chargers are created equally, but nothing
could be further from the truth. Wired explains that picking the right
charger with the right amperage (a measure of current) can mean the
difference between getting your phone charged while you work versus
waiting all day before you can unplug it.

You can get away with murder on most rechargeable technologies provided
you stay below a current of capacity/10 so a 3Ah AA cell ~300mA but to
charge it any faster than that safely requires thermal management.

The lithium batteries in most modern hitech kit require even more
sophisticated charging regimes and are protected from self immolation by
various safeguards which will brick it before anything bad happens (at
least in theory). In practice a few have caught fire. Exploding ecigs on
charge being the most amusing of the ones caught on camera:

http://www.dailymail.co.uk/news/arti...-fireball.html

I suspect ecigs skip out on the protection circuitry to save weight.

This isn't as simple as just "charge your device with the charger it
shipped with." You can actually use higher amperage chargers, like the
kind that come with tablets, to get your phone charged up in less time
than it would if you charged via USB or using the charger the phone came
with, and it won't cause a problem. Here's how it breaks down"

http://lifehacker.com/pay-attention-...adg-1492446246

The "myth" that fast charging will shorten battery life is generally
true unless the charger is quite sophisticated (and even then I have my
suspicions that the elevated charging temperature and overshoot will
shorten battery life). A crude rule of thumb is if the battery gets too
hot to touch comfortably then you are very probably damaging it.

The worst offenders I have seen for bad charging regime are wireless
phone handsets some of which use a small permanent trickle charge that
will ruin NiMH cells. Especially if the phone is rarely used.

--
Regards,
Martin Brown

This article also agrees with what I'm saying:

"You might think that all chargers are created equally, but nothing
could be further from the truth. Wired explains that picking the right
charger with the right amperage (a measure of current) can mean the
difference between getting your phone charged while you work versus
waiting all day before you can unplug it.

This isn't as simple as just "charge your device with the charger it
shipped with." You can actually use higher amperage chargers, like the
kind that come with tablets, to get your phone charged up in less time
than it would if you charged via USB or using the charger the phone came
with, and it won't cause a problem. Here's how it breaks down"

http://lifehacker.com/pay-attention-...e-to-juice-up-
your-gadg-1492446246

I noticed this (and posted about it here) a while back, when my (Nokia)
would go flat when being used as a satnav, despite having the charger
plugged in. Advice from here was to check the charger, and I discovered
the one I had been using was unlabelled, but the one for my wifes phone
was 2A. I switched to using that, and now the phone charges *and* works
as a satnav.

Indeed.

In article ,
Rob wrote:
As others have said, increasing current demands of newer equipment may
make the existing current limit a bit lacking in the near future.

I'd say the limit will be set by existing USB connectors.

--
Is the hardness of the butter proportional to the softness of the bread?*

Dave Plowman London SW
To e-mail, change noise into sound.

On 09/10/2014 11:08, Martin Brown wrote:
On 09/10/2014 10:17, Bod wrote:
On 09/10/2014 10:01, Bod wrote:
On 09/10/2014 09:50, Tim Watts wrote:
On 09/10/14 09:27, Bod wrote:

If the device being charged is designed for a 1 amp charger, then
using
a 2 amp will simply charge up quicker. I have used 2 amp chargers for
years with all of my devices, even the ones that were supplied with 1
amp chargers. I've never had any problems.

Not entirely - anything with a lithium based battery is supposed to
regulate its charging and discharging as going out of bounds in either
direction is dangerous (fire risk).

It doesn't mention anything about that in this article:

"The micro USB connector has become the de-facto standard, used by
almost everyone except Apple, so you only need to take one charger with
you. Most chargers will work on any mains supply, from 100 to 240 volts
AC 50/60Hz and the output is a standard 5 volts DC, but the current they
can deliver does vary, and may be insufficient to charge some devices.
The solution is to pack the charger with the highest rated output. This
will be printed on the case and is typically between 500mA (milliamps)
and 2.5 amps.

http://www.telegraph.co.uk/technolog...y-gadgets.html


Relying on the Telegraph for technology advice is unwise, but you have
evidently found some even more unreliable dross "advice" to quote below.

Here is something reasonably accessible about charging NiMH:

http://www.powerstream.com/NiMH.htm

And a slightly more technical one about charging Lithium ion:

http://batteryuniversity.com/learn/a..._ion_batteries

The higher rated charger will work OK with most things but some older
kit that assumes that it will never see more than 500mA USB supply
current could react badly to having 2A available.


This article also agrees with what I'm saying:

"You might think that all chargers are created equally, but nothing
could be further from the truth. Wired explains that picking the right
charger with the right amperage (a measure of current) can mean the
difference between getting your phone charged while you work versus
waiting all day before you can unplug it.

You can get away with murder on most rechargeable technologies provided
you stay below a current of capacity/10 so a 3Ah AA cell ~300mA but to
charge it any faster than that safely requires thermal management.

The lithium batteries in most modern hitech kit require even more
sophisticated charging regimes and are protected from self immolation by
various safeguards which will brick it before anything bad happens (at
least in theory). In practice a few have caught fire. Exploding ecigs on
charge being the most amusing of the ones caught on camera:

http://www.dailymail.co.uk/news/arti...-fireball.html


I suspect ecigs skip out on the protection circuitry to save weight.

This isn't as simple as just "charge your device with the charger it
shipped with." You can actually use higher amperage chargers, like the
kind that come with tablets, to get your phone charged up in less time
than it would if you charged via USB or using the charger the phone came
with, and it won't cause a problem. Here's how it breaks down"

http://lifehacker.com/pay-attention-...adg-1492446246


The "myth" that fast charging will shorten battery life is generally
true unless the charger is quite sophisticated (and even then I have my
suspicions that the elevated charging temperature and overshoot will
shorten battery life). A crude rule of thumb is if the battery gets too
hot to touch comfortably then you are very probably damaging it.

The worst offenders I have seen for bad charging regime are wireless
phone handsets some of which use a small permanent trickle charge that
will ruin NiMH cells. Especially if the phone is rarely used.

Hmm, there's an awful lot of conflicting advice out there regarding this
subject. There's even a charging device just been designed that can
charge a phone from flat to fully charged in 30 secs.

http://www.theguardian.com/technolog...ies-30-seconds

On 09/10/2014 11:32, Bod wrote:
On 09/10/2014 11:08, Martin Brown wrote:
On 09/10/2014 10:17, Bod wrote:
On 09/10/2014 10:01, Bod wrote:
On 09/10/2014 09:50, Tim Watts wrote:
On 09/10/14 09:27, Bod wrote:

If the device being charged is designed for a 1 amp charger, then
using
a 2 amp will simply charge up quicker. I have used 2 amp chargers for
years with all of my devices, even the ones that were supplied with 1
amp chargers. I've never had any problems.

Not entirely - anything with a lithium based battery is supposed to
regulate its charging and discharging as going out of bounds in either
direction is dangerous (fire risk).

It doesn't mention anything about that in this article:

"The micro USB connector has become the de-facto standard, used by
almost everyone except Apple, so you only need to take one charger with
you. Most chargers will work on any mains supply, from 100 to 240 volts
AC 50/60Hz and the output is a standard 5 volts DC, but the current
they
can deliver does vary, and may be insufficient to charge some devices.
The solution is to pack the charger with the highest rated output. This
will be printed on the case and is typically between 500mA (milliamps)
and 2.5 amps.

http://www.telegraph.co.uk/technolog...y-gadgets.html



Relying on the Telegraph for technology advice is unwise, but you have
evidently found some even more unreliable dross "advice" to quote below.

[snip]

http://lifehacker.com/pay-attention-...adg-1492446246

The "myth" that fast charging will shorten battery life is generally
true unless the charger is quite sophisticated (and even then I have my
suspicions that the elevated charging temperature and overshoot will
shorten battery life). A crude rule of thumb is if the battery gets too
hot to touch comfortably then you are very probably damaging it.

The worst offenders I have seen for bad charging regime are wireless
phone handsets some of which use a small permanent trickle charge that
will ruin NiMH cells. Especially if the phone is rarely used.

Hmm, there's an awful lot of conflicting advice out there regarding this
subject.

The blind leading the blind by parroting uninformed "technology" and
gadget blogs written by other clueless individuals.

There's even a charging device just been designed that can
charge a phone from flat to fully charged in 30 secs.

http://www.theguardian.com/technolog...ies-30-seconds

You have a reading comprehension problem and so from the headline does
the Grauniad editor. I would have expected better from them.

The startup is claiming a *NEW* battery technology based on organic
nanodot structures that they say can recharge in 30s. It doesn't make
any claims about stored energy density but their prototype battery for
the Samsung phone appears to be about the size of a brick.

http://www.theregister.co.uk/2014/04...in_30_seconds/

Is a slightly more informed piece about this technology "breakthrough".
There is too little publicly available information to give any kind of
informed opinion. Suspicious there is nothing in the patents database!

I am sceptical that it is anything other than vapourware at present.
There are devices that can take very fast rates of charge based on
capacitor technologies but they leak like hell.

--
Regards,
Martin Brown

On 09/10/2014 11:57, The Other Mike wrote:
On Thu, 09 Oct 2014 09:50:37 +0100, Tim Watts wrote:

On 09/10/14 09:27, Bod wrote:

If the device being charged is designed for a 1 amp charger, then using
a 2 amp will simply charge up quicker. I have used 2 amp chargers for
years with all of my devices, even the ones that were supplied with 1
amp chargers. I've never had any problems.

Not entirely - anything with a lithium based battery is supposed to
regulate its charging and discharging as going out of bounds in either
direction is dangerous (fire risk).

One would hope that a lithium battery installed in a device would have the
appropriate charge limiting and regulation circuitry within the device.

Supplying a USB device from a power source capable of sourcing say 100A at 5v
should *never* cause any issues.

You would hope that was the case, but the evidence of exploding ecigs
says that not all lithium batteries are properly protected. Typically it
is leaving them on charge for too long that does the damage...

They are notoriously tetchy about being over charged or over discharges
as fires of various manufacturers laptops will amply demonstrate.

It is a bit scary that the general public can buy raw lithium ion cells
with no protection at all if they know where to look and in AA format
too but delivering roughly twice the voltage of a normal AA cell.

--
Regards,
Martin Brown

On 09/10/2014 13:26, Martin Brown wrote:
On 09/10/2014 11:32, Bod wrote:
On 09/10/2014 11:08, Martin Brown wrote:
On 09/10/2014 10:17, Bod wrote:
On 09/10/2014 10:01, Bod wrote:
On 09/10/2014 09:50, Tim Watts wrote:
On 09/10/14 09:27, Bod wrote:

If the device being charged is designed for a 1 amp charger, then
using
a 2 amp will simply charge up quicker. I have used 2 amp chargers
for
years with all of my devices, even the ones that were supplied
with 1
amp chargers. I've never had any problems.

Not entirely - anything with a lithium based battery is supposed to
regulate its charging and discharging as going out of bounds in
either
direction is dangerous (fire risk).

It doesn't mention anything about that in this article:

"The micro USB connector has become the de-facto standard, used by
almost everyone except Apple, so you only need to take one charger
with
you. Most chargers will work on any mains supply, from 100 to 240
volts
AC 50/60Hz and the output is a standard 5 volts DC, but the current
they
can deliver does vary, and may be insufficient to charge some devices.
The solution is to pack the charger with the highest rated output.
This
will be printed on the case and is typically between 500mA (milliamps)
and 2.5 amps.

http://www.telegraph.co.uk/technolog...y-gadgets.html




Relying on the Telegraph for technology advice is unwise, but you have
evidently found some even more unreliable dross "advice" to quote below.

[snip]

http://lifehacker.com/pay-attention-...adg-1492446246


The "myth" that fast charging will shorten battery life is generally
true unless the charger is quite sophisticated (and even then I have my
suspicions that the elevated charging temperature and overshoot will
shorten battery life). A crude rule of thumb is if the battery gets too
hot to touch comfortably then you are very probably damaging it.

The worst offenders I have seen for bad charging regime are wireless
phone handsets some of which use a small permanent trickle charge that
will ruin NiMH cells. Especially if the phone is rarely used.

Hmm, there's an awful lot of conflicting advice out there regarding this
subject.

The blind leading the blind by parroting uninformed "technology" and
gadget blogs written by other clueless individuals.

There's even a charging device just been designed that can
charge a phone from flat to fully charged in 30 secs.

http://www.theguardian.com/technolog...ies-30-seconds


You have a reading comprehension problem and so from the headline does
the Grauniad editor. I would have expected better from them.

The startup is claiming a *NEW* battery technology based on organic
nanodot structures that they say can recharge in 30s. It doesn't make
any claims about stored energy density but their prototype battery for
the Samsung phone appears to be about the size of a brick.

http://www.theregister.co.uk/2014/04...in_30_seconds/


Is a slightly more informed piece about this technology "breakthrough".
There is too little publicly available information to give any kind of
informed opinion. Suspicious there is nothing in the patents database!

I am sceptical that it is anything other than vapourware at present.
There are devices that can take very fast rates of charge based on
capacitor technologies but they leak like hell.

I don't understand your accusation of "You have a reading comprehension
problem".
I only posted the link for information. It's down to the reader of the
link to comprehend the story and make of it as they will.
I did qualify my statements with this "there's an awful lot of
conflicting advice out there regarding this
subject."

On 09/10/14 11:18, Dave Plowman (News) wrote:
In article ,
Rob wrote:
As others have said, increasing current demands of newer equipment may
make the existing current limit a bit lacking in the near future.

I'd say the limit will be set by existing USB connectors.


as far as I've been told (by engineers current in the practise of Li-Ion
technology) all Li-Ion battery packs *must* contain local safety and
regulator electronics:

http://www.electronics-lab.com/artic...n_reconstruct/


I assumed (and this point alone may be wrong) that the safety circuit
would prevent overcharging and over-fast charging? Anyone know any better?

On 09/10/14 11:57, The Other Mike wrote:
On Thu, 09 Oct 2014 09:50:37 +0100, Tim Watts wrote:

On 09/10/14 09:27, Bod wrote:

If the device being charged is designed for a 1 amp charger, then using
a 2 amp will simply charge up quicker. I have used 2 amp chargers for
years with all of my devices, even the ones that were supplied with 1
amp chargers. I've never had any problems.

Not entirely - anything with a lithium based battery is supposed to
regulate its charging and discharging as going out of bounds in either
direction is dangerous (fire risk).

One would hope that a lithium battery installed in a device would have the
appropriate charge limiting and regulation circuitry within the device.


http://www.electronics-lab.com/artic...n_reconstruct/

It has some protection within the battery pack itself.

Tim Watts wrote:

The Other Mike wrote:

One would hope that a lithium battery installed in a device would have the
appropriate charge limiting and regulation circuitry within the device.

It has some protection within the battery pack itself.

some cells do, others don't

http://www.batteryjunction.com/efest-1090-flat.html

On 08/10/2014 20:07, Chris French wrote:
Fine, but the USB plug is on the bottom, which I generally find
annoying, and couple of outputs is useful

Not too fussed about which way up, but I'd like a good multi port
charger - have a fairly cheap two port and it works even on my (old)
iPad. But would like the convenience of three/four ports and all able to
supply full power.

Also looking for a similar spec. but for a car lighter socket... Several
out there but am finding it difficult to assess quality from the screen.

--
Rod