Power bank output question

[Patroclus]

Need some advice from those who understand about technicalities of phone charging/powerbank.

I'm thinking of buying a PB for my android phone. The phone's original charger only has 1A output, but the PB has 2.1A output.
If I charge my phone with the PB, will it charge at 1A or 2.1A ?
Does the phone have circuitry to limit the input current to 1A ?
I'm worried to cause damage to the phone /battery because of the much higher current input from the PB.

2nd question is about the USB cable.
For the PB to output 2.1A, does it need a special USB cable ?
Isn't common usb cable limited to only 500mA according to USB 2.0 spec ?

Thanks

 

[shabby]

Does the phone have circuitry to limit the input current to 1A ?

Yes, it'll pull as much power as it needs. No special cable needed.

 

[lopri]

Once again, the easiest rule to remember is that;

• Volt pushes
• Ampere pulls

Cables generally should not matter, but if they are too cheaply made there can be inefficiency issues due to resistance.

So to answer your questions - The phone will decide how much it will pull from the charger as long as the charger can meet the amperage. If not, the phone will draw as much as it can from the charger.

A Li-Ion battery will degrade over time no matter how "gently" it is recharged. It is true that higher draws will lessen its life expectancy. The question is matter of degree, which depends on the quality of battery and how much you care.

 

[lxskllr]

A Li-Ion battery will degrade over time no matter how "gently" it is recharged. It is true that higher draws will lessen its life expectancy. The question is matter of degree, which depends on the quality of battery and how much you care.

I prefer to charge via USB port(500mA), but I don't stress it if I have to charge fast.

 

[Patroclus]

Thank you all for the answer.
Thanks to Lopri. Your explanation is easy to understand & remember for me.
Got it now. Going to order Xiaomi 10400 mah PB now.