I bought https: smile amazon com gp product B008ZNWOYY ref oh aui detailpage o03 s00?ie UTF8&psc...

[G+_James Scouten]

I bought https://smile.amazon.com/gp/product/B008ZNWOYY/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1 to use a USB charger power supply in my car that is always on for my Note 4 would I want to just short the data wires or would I need to put a resistor to make it work as a charger?

https://smile.amazon.com/gp/product/B008ZNWOYY/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

[G+_James Hughes]

Usb is 5v, so not sure what you got the UBEC for.

[G+_James Scouten]

I need it for its 5v output

[G+_Robert Gauld]

The USB charger already outputs 5V -> the UBEC is pointless.

[G+_James Scouten]

This is for a DIY'ish charger to put in my car that doesn't shut off when I turn off the key So I am using the UBEC to convert the 12 volts of the car battery to 5 so I can charge my phone even when the ignition is off.

[G+_Robert Gauld]

Oh, I read that as the power was coming from a USB charger. For a simple charger just using the 5V and 0V should work fine. There's something more (I don't recall what) that you need to do to tell the device it can use fast charging - Google for DIY fast USB charger and you should find it.

[G+_Ben Reese]

I could be wrong, but I'm fairly certain the Note 4 supports Quick/Fast charge which will use 12v (or is it 9V?) at 2A... Exact details may be wrong. But that brings me to my question:

Why risk it on a DIY 15W charger when you can get an 18W (or 24W?) charger for <$20?

[G+_Ben Reese]

Other than that, I'd expect this to just work...

[G+_James Scouten]

The main reason for this is a always on USB charger that is wired(and fused) straight to the battery so that I can charge my phone with the key out of the car I had a jury rigged one in my last car but didn't want to reuse it as it caused 2-3db of static across the HF radio spectrum(I am a ham radio operator).

[G+_Eric K]

Why not pick up a USB car charger and then disassemble it and wire it to 12v directly? Trying to find a schematic that will show you how to apply the right resistance to the data lines in order to get a fast charge will be more problematic then disassembling a known working charger.

[G+_Eddie Foy]

Years back I made a iPhone charger.  Just hooking up the +5 and common doesn't work.  It needed some voltages on the data pins ti initiate the charging.

 

I think all I used were 3 smt 10K resistors between each pin to do the voltage drops.

(I think they were either 802 1205 series, but they bridged the pins beautifully )

[G+_Ben Reese]

This guy didn't even send a signal to data pins and I don't know that it would be necessary.

 

For quick charge, I thought there was circuitry in the phone that sent a signal to the charger to say it's QC compatible (maybe the signal was on the data pin?). That would prompt the charger to send a higher voltage.

 

This Android Authority post says QC 2.0 will do 5, 9, 12V and up to 18W. Same article says QC 3.0 will handle 3-20V, but with the same 18W max. http://www.androidauthority.com/quick-charge-3-0-explained-643053/