USB hub for charging only?

[b0redom]

Hi All,
I've got a lot of gadgets which use USB for charging. Rather than have oodles of sockets taken up, I was thinking of getting a 8 port (or more if possible) USB hub and just running USB cables to that. Are all USB hubs created equal or do I need to look for something specific?

It'll be used to charge:

Harmony remote
iPhone
iPad
Bike lights
Garmin 910XT

etc.....

Cheers....

b0redom

[peterb]

A USB2 port will (should!) provide up to 500mA. So an 8 port hub would need a 4A power supply if it is going to supply 500mA per port simultaneously. I'm not sure that akll hubs do provide that, the assumption being that few users will connect lots of high current devices to a hub - most people would add a mouse, keyboard, flash drive, printer and so on, and maybe one or at most two hard drives. (And some hard rives need two ports anyway, to provide additional power)

So if the hub PSU is 4A or more, then you would probably be OK.

"Ah", I hear you say "but what if I buy a hub and add my own PU?"

Well, you could, but then you might need to worry about the internal wiring of the hub. If the mfr didn't design the hub to provide 500mA/port simultaneously, you might still run into snags.

USB3 is slightly different, in that the design specs allow for greater current, and variable voltage, but that is negotiated by an intelligent peripheral. I'm not sure what the position is with regard top external USB3 hubs, but the same considerations apply - ultimately you are limited power the power rating of the PSU.

[b0redom]

Ah right. So any recommendations? Power calculations are not my bag. I presume something like this should cope?

http://www.amazon.co.uk/Anker%C2%AE-.../dp/B006TTA75Y

[peterb]

It has a 3A power supply, but says that it will provide 1 Amp to 5 ports simultaneously, which doesn't add up, unless they are doing some nifty internal voltage conversion (5A at 5V is 25 Watts, 3A at 12 V is 60 Watts, so it is possible that they are doing something like that with an internal switched mode voltage converter)

However, it also says

• This hub is not designed to serve as a standalone charger and will not charge an iPad tablet or any other device with non-standard charge requirements.

So I wouldn't recommend it, neither am I really in a position to suggest anything else.

Many devices have bespoke chargers because of a particular battery chemistry. LiION batteries have very specific charging requirements. Other devices may have a generic PSU with charging and regulating ccts built into the device (like a laptop, for example).

I see you are planning to recharge bike lights - are they a USB connection?

[mycarsavw]

I have one of these - http://www.amazon.co.uk/gp/product/B00EKDVGKQ/ - and it's used to charge a whole load of devices including a Nexus 7, a Kindle, a Moto G and a One X.

I wanted something with 8 ports but couldn't find anything that would put out enough power to charge the Nexus and a phone at the same time.

It takes an age if all ports are occupied but that's only happened once in 3 months.

[Pob255]

Actually you can charge an ipad off a standard usb2 port, if it's turned off, it will take a long time but it will charge if it's turned off, if the ipad is on then it will use more than the 500mA being feed in so it will not charge.
I've recharged an ipad off usb2 before, had to leave it overnight but it worked.

As to Hubs, if the hub doesn't have a separate power supply then it will not supply 500mA to each thing plugged in because USB2 is limited to 500mA, so you can only pull a max of 500mA off of any single USB port or single header (motherboard headers are double, with the top and bottom row of pins each being one usb port), you cannot put in a hub and magically get and extra 500mA out of it.

That said there are a couple of sneaky ways round it.
You could have a hub that will let you pull more amps would be if it was USB3 (2.5amp) at the pc end and usb2 at the hub end.
Or multi-usb connectors, you can get cables that connect to the pc via multiple USB plugs, only one provides data but it lets it pull current from two sockets, so you can get a usb2 device running off more than 500mA

Ideally you need a USB hub with separate power feed to act as a stand alone charger.
In theory as all you want is the power not the data, you could make a charger by getting some usb2 sockets and wiring them up to a 5v dc power supply, on usb2 the middle two pins supply the data and the outer two pins supply the current (one is +5v the other is earth, cannot remember which is which) the metal outer casing is just a shielded earth.
That's basically what the thing mycarsavw suggested is

[DanceswithUnix]

I tried a usb hub to charge games controllers (Wii & PS3).

Didn't work. I think it just didn't have the grunt to charge more than one device at a time, so nothing got charged.

Get a proper charger that can manage 2A on a port.

[herulach]

Do you need a hub? (i.e. does it need to be switched between data/charging?) if its just charging I have two portapow devices, both deliver 4A over 4 ports (4x1 or 2x1 +3x less) and they're pretty robust. Will charge my nexus 10 from dead in about 5 hours

[b0redom]

Doesn't need to do data, just charging.

@peterB the lights are BlackBurn fleas. They're amazing as 'to be seen' lights for cycling, or to clip on a running cap for evening/morning running.

[amjedm]

I would recommend something similar to what mycarsavw has

Anker 40w 5-Port Desktop Charger for iPad, iPhone, Tablets and Android Devices - £16.99 with code Sold by AnkerDirect and Fulfilled by Amazon.

Direct Amazon.co.uk link - Anker® 40W 5V / 8A USB Wall Charger 5-Port Family-Sized Desktop Charger with 5-Foot Power Cord for iPads, iPad Air, iPad Mini, iPhone 5S 5C 5 4S 4 3GS, Samsung Galaxy Tab, Galaxy S4 S3 S2, Google Nexus, Android Devices and Virtually All USB-Charged Devices

[Butuz]

Yeh be careful you can easily fry a cheapo USB hub if the PSU is poor as they are often not designed to provide the "full wammy" through all ports at the same time.

Butuz

[josephlck]

I think it depends on how you use it. My iPad for example will still charge from a normal USB (even though it says "not charging") so if they are plugged in for a fair amount of time/overnight I don't think it matters too much. A device which supplied a high current (A) would charge things faster though. Personally, I have an external phone battery made by Anker and it works well. I would definitely recommend them.

The other thing that would be worth investigating is wireless charging. I think it's still in it's infancy, but if you can find the adapters for your devices, it could save a lot of hassle.