USB Charging question

[Bunnykiller]

it states 60W 12A therefore 5V 6 slots so an average of 10W per slot at 2A each at 5V when all 6 slots are occupied

 

[AttyPops]

it states 60W 12A therefore 5V 6 slots so an average of 10W per slot at 2A each at 5V when all 6 slots are occupied

Yeah, but since you AVERAGED it out, that's just a mathematical calculation in your head for your own "fun"...it's meaningless to the device. For example, could one port be 2.5 amps and another be 1.5 amps? Or is there an amp limit per port that's important? We don't know.

So maybe I'm missing whatever point you're trying to add?

We already know that he has a max draw of 1.5 amps right now with the devices he has. I'm not sure any charger requires more than 2 amps (currently...pun intended).

 

[r77r7r]

Yeah, but since you AVERAGED it out, that's just a mathematical calculation in your head for your own "fun"...it's meaningless to the device. For example, could one port be 2.5 amps and another be 1.5 amps? Or is there an amp limit per port that's important? We don't know.

So maybe I'm missing whatever point you're trying to add?

We already know that he has a max draw of 1.5 amps right now with the devices he has. I'm not sure any charger requires more than 2 amps (currently...pun intended).

 

[ian-field]

Thank you!!

I guess I was confused because I was under the impression that the cables didn't matter - that they were just carrying the power that is supplied to the device. It's the device and the supply (hub/wall wart/etc.) that matter.

Some USB charger wall-warts can supply a couple of amperes - as long as the output is strictly 5.0V, there's no problem.

Some are rated at 5.2V, technically this is still within spec and is only likely to be a problem with flaky cheap imports.

 

[four2109]

I've got this one. I bought it before xmas. I use it for isticks, egrip, eroll, itastevv, cell, bluetooth earpiece.
I love it.
I only wish i had ordered a 6 pack of 12 inch cords.

http://www.amazon.com/Technology-Ch...-17&keywords=Multi+Device+USB+Battery+Charger

 

[ian-field]

You mention stressing the wallwart if it's under powered for what a device needs. You are absolutely correct. Under lab conditions an underpowered charger will start to drop voltage as a result of being overloaded. Good chargers will most likely be fine but will get warm to hot if run that way. Cheap chargers can overheat and catch fire.

With that said hopefully no one is hooking up a device with a 1A or 2A charge requirement to a cheap 0.5A wall charger.

A SMPSU wall wart usually has current sensing, the few that don't usually go bang anyway. You probably won't find an iron-cored transformer USB wall-wart, but the transformer general type are required to have a thermal fuse embedded in the primary winding.

Still; its best not to tempt fate - especially if you're using dodgy cheap imports.