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Good quality, high-power USB charger?
Si_Crewe
Posts: 40,202 Forum Member
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Looking for a good quality USB charger, preferably from a name-brand, capable of supplying a single output of at least 3 amps or more.
Missus wants a second charger that she can leave at work to charge up her tablet if required.
I cheaped-out and bought an unbranded one from eBay which promptly exploded spectacularly when we plugged it into the mains.
I replaced it with a Samsung Galaxy charger which claims to have an output of 2 amps (via a single USB socket) and should charge the 10Ah battery in the tablet in about 12 hours but, in use, it takes at least 24 hours so it obviously isn't pumping out the claimed 2 amps.
I've had a look around the internet and it seems like the vast majority of chargers which claim to have a high output actually have a whole bunch of USB sockets and it's likely that the specified output is the combined total of all the sockets.
What I'm looking for is an after-market charger than can pump around 3 or 4 amps through a single USB socket.
From a reliable brand, which won't explode.
Missus wants a second charger that she can leave at work to charge up her tablet if required.
I cheaped-out and bought an unbranded one from eBay which promptly exploded spectacularly when we plugged it into the mains.
I replaced it with a Samsung Galaxy charger which claims to have an output of 2 amps (via a single USB socket) and should charge the 10Ah battery in the tablet in about 12 hours but, in use, it takes at least 24 hours so it obviously isn't pumping out the claimed 2 amps.
I've had a look around the internet and it seems like the vast majority of chargers which claim to have a high output actually have a whole bunch of USB sockets and it's likely that the specified output is the combined total of all the sockets.
What I'm looking for is an after-market charger than can pump around 3 or 4 amps through a single USB socket.
From a reliable brand, which won't explode.
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Comments
If the tablet charging circuits use current limiting to regulate the charge current then it won't make a blind bit of difference if the charger is 2A, 3A or 3,000A the current drawn will be fixed by whatever the tablet requires.
http://www.amazon.co.uk/Desktop-Charger-PowerIQ-Technology-Samsung-White/dp/B00EJA28ES/ref=sr_1_4?ie=UTF8&qid=1428666714&sr=8-4&keywords=anker+usb+charger
Also to add, if this is a iPad with a lighting connector then you will need a certified USB cable to get maximum charging speed
The USB 1.x and 2.0 specifications provide a 5 V supply on a single wire to power connected USB devices. A unit load is defined as 100 mA in USB 2.0, and 150 mA in USB 3.0. A device may draw a maximum of 5 unit loads (500 mA) from a port in USB 2.0; 6 (900 mA) in USB 3.0.
While that may be USB specification, most phones and tablets will draw more current for charging if available from USB connection. iPad for example draws 2.1A and that is now seen as some sort of industry standard for charging. I believe there are several Samsung, Asus, Hudl tables that will use around 2A if available.
I havn't seen the spec but QI quick charge 2.0 used by Nexus, Samsung and others I believe has an even higher capability but you need a compatible charger.
The charger I linked to will pretty much charge anything out there except QC 2.0, at maximum speed possible.
This.
I have a couple of the 40w chargers and a 60w charger (keep an eye out on hukd for offers). They are excellent products.
The fact that the tablet quite happily charges in 4 or 5 hours using the OEM charger suggests this isn't the case.
Course, there certainly might be some incompatibility which prevents the Samsung charger operating at full capacity but that's why I'm looking for a charger that will pump out a high current.
Oddly enough, I've just had almost this exact conversation.
Bottom line is that USB chargers now pump out current far in excess of the specifications intended for USB devices.
The worrying thing, IMO, is that there's no regulation of cabling.
I recently bought a bunch of those "flat" USB cables and, at a guess, I'd say the wires in them are probably of a similar gauge to the wires in a telephone cable and there's no way you'd want to pump 2 or 3 amps through those.
The USB cables which came with the tablet, and the Samsung charger, are noticeably chunkier than most USB leads and I'd assume that's 'cos they're designed for higher loads.
Its not the amps, its the watts that would be main problem and at 5v, even 2 or 3 amps is only 15 watts and it is not going to cause a big problem. Biggest problem with cheap cables is the wire gauge is so crap that the wire snaps inside the cable (normally at the connector). If you look at the official apple cable supplied with the iPad, its surprisingly thin but works fine. More expensive cables might be thicker but if its all insulation and wire gauge is still rubbish then cable will still fail.
If you try to charge say an iPad from a Samsung charger you are not likely to get the best performance, because the charger signals to the device whether it is capable of more than the USB standard 500mA current.
Apple does it one way, everyone else does it another way. So an Apple device on a non-Apple charger doesn't necessarily work well as it has no idea that the charger can pump out 2A
I've also had some interesting USB cables. They didn't seem to heat up noticably, but they make the connected device take years to charge
The problem is that if the device cannot ascertain the maximum safe power draw then it then defaults to 500mah for safety reasons.
Its not all bad, in that for smartphones, defaulting to only 500mah is much better for the battery.
I bought his one a few months ago.http://www.amazon.co.uk/dp/B00PK1IIJY/ref=sr_ph?ie=UTF8&qid=1428947930&sr=1&keywords=anker+60w+6-port
PS,wile you're at it, I'd pick up a couple of their micro USB charging cables. They are the best I've ever used.
http://ecx.images-amazon.com/images/I/71LNSzJgzHS._SL1500_.jpg