Using ATX 5v to charge cell phone?

[NCC10281982B]

The battery like on both my SGS4 and N7 sucks. I have done all the usual troubleshooting steps for battery drain and not charging. I work for google supporting Android devices, BTW. So it occurred to me "hey I should try using the 5v from my computer to charge these things!" Putting together the necessary cables is kid's play.

 

The question is would I blow up / destroy my phone / tablet by doing this? If I recall the Ohms law lectures from  physics 109 properly, doing so should not. 

[dr_bowtie]

usb plug in the PC not do the same thing?

[ohldboy]

What is the Amp rating on your phone chargers?

USB2.0 is rated 500mA (2.5 watt)  and USB3.0 is rated 900mA (4.5 watt) I think. Whether one socket can pull combined rating I have no idea (remember USB2.0 devices using 2 plugs?   These are available computer switched on or off with newer? builds?

Power supply obviously can exceed these on 5 volt rail.

Generally a device like a phone will not (by design) pull more than it can use.

My exceedingly cheap smart phone uses a 4.9V 0.7A charger, my amazon kindle charger is 0.85A.  I've charged both off PC.

Edited March 4, 2014 by ohldboy

[Waco]

If your motherboard has a "supercharger" port it's really just a beefier port designed to allow draw up to 3 amps (usually).

 

Many powered USB hubs come with a higher power port as well.

[Andrewr05]

Technically a device should only ever draw what it needs, but I'd personally be a bit leary about running that without any sort of fuse or protection in the line.

[NCC10281982B]

Thanks guys. I've been putting up with the classic "device not charging"

[cirro]

LOL Those s3/s4 phones battery life is a JOKE. I love how the s4 with its brand name charger can't exactly charge while its being used (or use things like the camera when battery is low)

 

I have ghetto-rigged a couple devices to charge because customers don't bring them in with the device, they sometimes die on me halfway.

 

I don't know why they don't embrace batteries like the newest generation of apple's ipads, I would love a 8000mAh battery in my phone.

 

IMO - if the battery life on your S4 is not tolerable to you, I would honestly root & install a vanilla stock rom. all those background apps and utilities you will never use won't be on it.

 

Samsung phones are the new AOL's aka "The Kings of Bloatware"

 

oh , sorry. about the original question.. only device I have hurt using "not-recommended" charging methods was a Acer Iconia Tab, but they hae battery issues without me! lol

[NCC10281982B]

@ I actually DO want to install stock kit kat on my GS4. I got as far as rooting it for the purpose.

 

I am actually trying to build a "high powered" charging station for both my GS4 & Nexus 7. Same thing with the battery drain on the N7.

 

I am using a 5VDC 8A Switching Power Supply (40 Watt) for the project. The issue not is when testing the rig the test GS3 phone is hot charging. Do / do not I have to power one of the data caples had have a resistor someplace in the cutrit in order to "trick" the phone?