On 13/12/2016 23:26, Tim Watts wrote:
On 13/12/16 21:28, Nick wrote:
On 12/12/2016 11:42, Stephen wrote:
Hello,

I bought an unbranded wall-wart to usb output charger from CPC, hoping
to use it to charge my mobile phone or tablet (both are Samsung). When
I connect either device using the original Samsung cable, neither
device charges.


I believe Samsung chargers used a voltage which exceeded the USB
standard and Samsung devices only charge properly with this over
voltage. Something like 5.2 volts instead of 5 (I made that up just to
give you an idea)

With my really old Samsung tab it was the case that it would charge with
other USB chargers but was really slow.

However recently I have bought a couple of chargers and it charges fine
with them, one a plug socket I bought only last week. I can give you
specific devices if you are interested but maybe you should try all the
chargers you have available.





5.2 V is within USB spec IIRC.

The magic forumula is a resistor chain between +5V, 0V and the data lines:

http://blog.curioussystem.com/2010/0...vice-charging/


(any broken images, click on them, the preview is broken)

Yep, I did see a similar explanation and reposted to correct my initial
post. I had read it was over voltage a few years ago but this appears a
more convincing argument. Especially when 2 or 3 years ago when I had
the problem I tried 4 of 5 non Samsung chargers and none of them worked
(fast charge). Whereas recently I have bought two new non Samsung
chargers, both of which fast charged.

The one I bought last week was. £11.85

http://www.screwfix.com/p/british-general-13a-2g-sp-switched-socket-3-1a-2g-usb-charger-white/8529p

However I'm tempted to buy some more and this is less money £10 for but
only 2.1A instead of 3.1. Maybe it doesn't do this fast charging either
I can't see how to tell, apart from buying and trying.

http://www.screwfix.com/p/bg-13a-2-gang-sp-switched-socket-usb-charger-outboard-rocker-white/8534f?cm_sp=homepage-_-home-_-8534f