Safe charging input

[Hayden]

I have a modified USB port that can deliver about 4amps at the normal USB 5volts will that effect my phone if I charge from it? Will the phone suck to much power and damage the battery?
I'm assuming the circuitry to limit the battery from charging to fast or over charging is built into the phone and not in the charger?

Cheers guys

 

[Mooly]

if I charge from it? Will the phone suck to much power and damage the battery?

No.

I'm assuming the circuitry to limit the battery from charging to fast or over charging is built into the phone and not in the charger?

Yes, the charge circuit is within the phone.

 

[AndrewT]

It's the 5V that allows safe charging.
the tolerance of the USB's 5V is fairly wide, something like ±5%
But don't go outside that, stay close to 5V and all your chargers will be self protected.

Except when they are a rip off clone from some criminal organisation.
Then all bets are off.
We had yet another customer information documentary on TV a couple of nights ago.
The fires/explosions from badly manufactured clones was frightening.
And even worse to unprotected lithium cells.

 

[Refugee1]

Very cheap E-cig batteries are safe as long as the port is limited to 500ma. If they are charged on an unlimited port the pass device inside the charger will overheat and fail short circuit causing the battery to explode.