How to test if 2A (2000 mA) USB mains plug really is 2A?

[King Mustard]

I bought a 5V 2A mains plug from eBay to charge my tablet but I get the feeling it's actually only 500 mA or 1000 mA as my tablet charges slowly.


Is there a device I can buy to test USB mains plug amps?


Could the USB cable be the issue? Is there a device to test those?

 

[ElectroChem]

Measuring the current draw of the charger is easy with a clamp meter and breakout cable, but won't be very informative as the efficiency is unknown, and can vary widely.

Measuring the DC amps could be done by butchering a cable to get access to the wires, then using a multimeter or low range DC clamp meter to see the current used when charging.

 

[DuaneMHunt1976]

This will test a USB but you will need a Cable to hook it up to, and to the device.
Mini USB Power Current and Voltage Tester Detector USB Mobile Power Current Test | eBay
or maybe a more posher one
USB Charger Doctor Capacity TIME Current Voltage Detector Battery Tester Meter | eBay

If it was a charger with its own Cable you could adapt it so it could fit one of these
http://www.ebay.co.uk/itm/10pcs-OTG...cro-Android-/181800531054?hash=item2a5427f46e

You could change a Socket to have a built in USB and then all you need is the cable
(tho my first one, also ive not gotten a new one yet.. is Dead only a month after installing!)
Socket with USB Switches & Sockets | Wiring Accessories | NoLinkingToThis

 

[NDG Elecs]

This may not be true but I read somewhere that some tablets/smart phones will only accept a trickle charge from an unknown charger. That is too say the tablet will recognise it's official charger and let it charge at 2A but may only accept 500mA with an unknown charger.

Also, watch what you buy on flea bay. I never buy from eBay, partly cos I had PayPal issues, but also I feel it's like buying something from some random bloke in a pub.

 

[shanky887614]

This may not be true but I read somewhere that some tablets/smart phones will only accept a trickle charge from an unknown charger. That is too say the tablet will recognise it's official charger and let it charge at 2A but may only accept 500mA with an unknown charger.

Also, watch what you buy on flea bay. I never buy from eBay, partly cos I had PayPal issues, but also I feel it's like buying something from some random bloke in a pub.

yes that is correct.

usb2.0 spec is 500mah.

now if you try to charge a tablet/iphone on it. it will take forever.

i read about it then experimented by using a voltage divider and got 2amp out of my charger.


the device looks at the volts on D+ and D- to grnd pin and from that it can tell how much current is safe to draw


basically a usb plug is made up off.

positive
data+
data-
ground


if you want a cheap charger go to tesco and buy one for nexus devices there cheap and good quality

 

[shanky887614]

I bought a 5V 2A mains plug from eBay to charge my tablet but I get the feeling it's actually only 500 mA or 1000 mA as my tablet charges slowly.


Is there a device I can buy to test USB mains plug amps?


Could the USB cable be the issue? Is there a device to test those?

there are apps on the playstore etc that will tell you the charging rate in real time.



you could make a lead up with the right resistors but there is a chance you will destroy your/a charger

 

[Hellmooth]

What kind of tablet?

 

[davesparks]

If you are going to spend £--- on a tablet then why not spend a few pounds more on a decent charger rather than an eBay special?

 

[shanky887614]

If you are going to spend £--- on a tablet then why not spend a few pounds more on a decent charger rather than an eBay special?

i would pmsl if he did force it to charge at 2ah with that charger and then in melted