Question about charging cables

[winlogon2]

Hi,

I'd like to know any known consequences of using an inappropriate voltage for charging (HTC owner here)

From my experience, charging with the original HTC cable, or my gf's samsung cable is just fine.
Charging with some chinese micro-usb cable from ebay makes it charge 2x or maybe 4x times slower, and causes lags when using phone while charging (sliding desktop gets weird, etc.), but it's still about 5V i believe.

Anything dangerous if I the input gets lower ? Like 4V or 3V

(Also, if anyone knows the cause of the lags with chinese cable, please share your knowledge )

Thanks

 

[palmtree5]

Hi,

I'd like to know any known consequences of using an inappropriate voltage for charging (HTC owner here)

From my experience, charging with the original HTC cable, or my gf's samsung cable is just fine.
Charging with some chinese micro-usb cable from ebay makes it charge 2x or maybe 4x times slower, and causes lags when using phone while charging (sliding desktop gets weird, etc.), but it's still about 5V i believe.

Anything dangerous if I the input gets lower ? Like 4V or 3V

(Also, if anyone knows the cause of the lags with chinese cable, please share your knowledge )

Thanks

If the input is lower than what the stock charger outputs, the device will just charge slower (I think). If it's higher, it will charge faster but you also risk overheating the device. Also, I believe the output would be more important in this regard (i.e. if the stock charger outputs 0.7A but you're using a charger that outputs 2A, then you might overheat the device)

 

[mplevy]

There is such a thing as a Fast Charge USB Cable The ones that charge the device quickly are likely that spec while the slow cable is likely just a standard USB cable. I can't see any harm in slow charging if the only difference is the cable (if the wall-wart is the same).

 

[dibblebill]

Any USB-based phone charger should be outputting 5V, it's the standard. The difference is the amperage. My HTC One and Nexus 10 WILL charge on a 0.5A charger here at work, but I have to put them to sleep and leave them like that to charge them. 0.5A = standard PC USB port. My 1A charger here is slightly faster, and my 2A chargers at home are the fastest.

Cables may vary in the amperage they'll carry as well.

 

[winlogon2]

Any USB-based phone charger should be outputting 5V, it's the standard. The difference is the amperage. My HTC One and Nexus 10 WILL charge on a 0.5A charger here at work, but I have to put them to sleep and leave them like that to charge them. 0.5A = standard PC USB port. My 1A charger here is slightly faster, and my 2A chargers at home are the fastest.

Cables may vary in the amperage they'll carry as well.

I don't get you exactly. The amperage depends on the voltage, doesn't it?
If you charge your phone with two different 5V chargers, the amperage won't change.. (i thought that the amperage indication on a charger is to tell the amperage limit not to overheat the charger.)

 

[John Bean]

It's not that simple. The device can regulate the current it draws and the source can indicate maximum current in conjunction with the cable wiring (that's why "fast charge" cables work), so a 2A (max) charger with the correct cable may well charge a device that "knows" about it much faster than (say) a 1A charger.

My Nexus 7 is a case in point; it charges much faster with the supplied charger and cable than it does connected to any generic charger, even though both are 5V.

 

[winlogon2]

It's not that simple. The device can regulate the current it draws and the source can indicate maximum current in conjunction with the cable wiring (that's why "fast charge" cables work), so a 2A (max) charger with the correct cable may well charge a device that "knows" about it much faster than (say) a 1A charger.

My Nexus 7 is a case in point; it charges much faster with the supplied charger and cable than it does connected to any generic charger, even though both are 5V.

Oh now that's interesting - how exactly does it "indicate" its max current ? (the cable, right? not the charger)

I thought a cable was just some metal, how can the device know the max. current allowed ?

Thanks for your replies

 

[John Bean]

It's a bit of both; the charger wiring may or may not use the data lines in various ways to "fake" the same information passed from a real USB port to indicate maximum current. A normal data cable plays no part in the process - other than the bad effect of a cheap cable of course. It's a pretty crude indicator but is intended to dissuade devices from attempting to draw excess current from fragile sources like USB ports on laptops while allowing fast charge from a dedicated charge port.

"Fast charge" cables are wired to fool the device into thinking it is always connected to a high-current charging device no matter what the real port is. The cable only connects to the +/- power lines at the USB end and is wired internally fake the current limit information. Such a cable can't be used for data, it works only for charging.

Unfortunately not all manufacturers adopt the same de facto standard, so no all devices work correctly with all chargers (or fast charge cables). In particular Apple do their own thing with charging (don't thy always?) along with a few others. This is why a phone often charges faster with the charger/cable it came with than another that seems to have the same spec but may have slightly different wiring internally.