Charging & Cables

Zascar

Does anyone else find that different chargers seems to charge at totally different rates? I’m wondering can anyone explain the whole voltage/ampage thing so I can try to figure it out. I have a Blackberry charger which is super quick, my standard htc one is fine but if I swap out the cable for a longer one it takes forever.

Does anyone know an app that tells you the exact strength of the charge the phone is getting?
Thanks

rok

yes my Samsung Galaxy s4 charges much faster when I use an older HTC usb charger instead of the one that Samsung supplied, dunno why though

longhalloween

Each charger has a current output on the back of it. Decent chargers for mobile phones have outputs of around 1A, chargers for tablets are around 1.4A. You'll often find chargers of 500mA or less.

Basically, the lower the current output, the longer a battery takes to charge.

rok

Samsung charger I have at work has an OUTPUT= 0.55A, Samsung travel adapter model number ETA3U30UBE.

Zascar

So what about a charger that is a usb cable and has a wall socket adaptor? It can charge pretty fast from the wall but plug it into a laptop or computer and its really slow...

rok

The htc one I have is a charger that is a usb cable and has a wall socket adaptor

coylemj

longhalloween wrote: »

Each charger has a current output on the back of it. Decent chargers for mobile phones have outputs of around 1A, chargers for tablets are around 1.4A. You'll often find chargers of 500mA or less.

Basically, the lower the current output, the longer a battery takes to charge.

+1 The amp number quoted is the maximum that that charger will deliver. The charger is designed for the device it ships with and specifically it's optimized for the battery in that device so that it doesn't charge it too fast or too slowly.

The bigger tablets have bigger batteries so the charger that ships with them probably wouldn't be recommended for older phones with smaller screens because the current would be a bit on the heavy side and might cause the battery to overheat or shorten it's overall life. Conversely, using an older charger with a tablet or big screen phone would probably result in too long a charge time.

bren2001

Zascar wrote: »

So what about a charger that is a usb cable and has a wall socket adaptor? It can charge pretty fast from the wall but plug it into a laptop or computer and its really slow...

That is because you are using the 5V output from the laptop to charge the device as opposed to the switching converter in the plug. The laptop can only provide about 500 mA (if even). Look at the back of the plug and it can provide a much greater current.

The usb cable has nothing to do with it. It just "transfers" the current.

droidman123

Zascar wrote: »

So what about a charger that is a usb cable and has a wall socket adaptor? It can charge pretty fast from the wall but plug it into a laptop or computer and its really slow...

It will always be a hell of a lot slower charging from your laptop then a wall outlet.

ED E

bren2001 wrote: »

The usb cable has nothing to do with it. It just "transfers" the current.

Incorrect. Cheapo cables and long cables reduce the current to the device itself. This has been measured. I myself have one particular chinese cable that makes a really noticeable drop in charge rate. You'll also often notice that tablets have quite chunky cables, this is because they're intended to carry 2.1-2.5A.


OP: Whats the handset? Suit the charger to the handset.

Most modern top tier phones do just fine on 1.5A. Slow charge at 1A if you want, lower than 850mA and you'll barely charge at all.

And as above, USB ports on a PC are 500mA max. Not nearly enough for the draw of contemporary handset. It'll charge, but sloooooowly.

bren2001

ED E wrote: »

Incorrect. Cheapo cables and long cables reduce the current to the device itself. This has been measured. I myself have one particular chinese cable that makes a really noticeable drop in charge rate. You'll also often notice that tablets have quite chunky cables, this is because they're intended to carry 2.1-2.5A.


OP: Whats the handset? Suit the charger to the handset.

Most modern top tier phones do just fine on 1.5A. Slow charge at 1A if you want, lower than 850mA and you'll barely charge at all.

And as above, USB ports on a PC are 500mA max. Not nearly enough for the draw of contemporary handset. It'll charge, but sloooooowly.

Unless the copper used is almost non existent or you are talking about 1+ meter long, it makes no difference.

longhalloween

ED E wrote: »

Incorrect. Cheapo cables and long cables reduce the current to the device itself. This has been measured. I myself have one particular chinese cable that makes a really noticeable drop in charge rate. You'll also often notice that tablets have quite chunky cables, this is because they're intended to carry 2.1-2.5A.

Yep, resistance increases with length and cross sectional area. So if you have a long cable (2-5m), or a cheap chinese one where they only put in the bare minimum amount of copper, the resistance increases and current decreases.

ED E wrote: »

And as above, USB ports on a PC are 500mA max. Not nearly enough for the draw of contemporary handset. It'll charge, but sloooooowly.

Yep, sometimes it's hardly worth your while using a laptop to charge anything. Also USB ports are often paired together so if you're charging two things at the same time they'll each get 250mA max.
Buy a decent 1A+ adaptor online for a fiver and you'll be grand.

Zascar

Ah ok that makes sense, I have two cables I use regularly and they are both about 1.5m-2m long, and they are cheap ones from China. One is by my bed and I dont mind if it's slow as it charges overnight. The other was in the car connected to the back of my head unit, and with the screen on with gps, it barely charges at all...

longhalloween

Zascar wrote: »

Ah ok that makes sense, I have two cables I use regularly and they are both about 1.5m-2m long, and they are cheap ones from China. One is by my bed and I dont mind if it's slow as it charges overnight. The other was in the car connected to the back of my head unit, and with the screen on with gps, it barely charges at all...

The head unit may not even supply the 500mA.

ED E

For the car pick up something like this:

beauf

http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-is.html

A lot of computer/laptops and USB charges don't supply the full charge anyway.

Two I find quick are the NOKIA AC-15X ( DC 5.0V 800mA) and Sony EP-800 (850 mA). A lot of the other branded ones I have are 500mA only.

deckie27

Cables, cables, cables.


2amp charger for me note2
original cable 2amp all the way down to 300 Milliamp on cheap Chinese cables.

If you have a newish Samsung try the app
" galaxy charging current *lite* "