OTG, charging and extrenal batery pack works HP stream 7

[leo_kendall]

I have seen alot of people saying that the hp stream  7/8 do not support usb charging and using a usb device at the same time.  Well it works on my tablet.  The charging is slow but it do charge.  All i did was take a usb OTG cable and taped into the positive and negative usb power wires.  Then i dissable the Microsoft ac adapter device driver.  It Works

[leo_kendall]

[kyle_b]

That is interesting, I guess you could also connect the provided AC adapter to the OTG cable instead of a USB port and then it would charge at the normal rate?

[ar8001]

i build the same cable .... but it do not charge the pad .... 

i'll test is for a longer time now and give you guys a report

[Annelizabeth]

I have one that works too.  It doesn't show that it's plugged in or charging but the % remaining slowly goes up..

I also got a regular OTG + USB hubwith a switch, that one does not work...

[judgedreddd]

So how exactly did you make this cable? Was it like one of these diagrams?

[david1024]

Looking at the picture posted above (zooming in on it) it looks like the cable that worked was wired like your top diagram.

E.g. In words: Connect all 3 red power leads together.  Connect all 3 black 'ground' leads together.  Run the remaining two data lines (in kind) between the tablet data connnections and the 'usb data' connector.

ALSO, keep in mind that the stream7 (and some other devices) can be quite neurotic about the +5v they get.  It needs to be really high in the allowable USB range. (4.45–5.25 V is acceptable, but users report that the tablet will terminate charge at around 5.17V-- so you need a supply that ideally can do 5.22V +/-0.03V while supplying up to 1-2A)  Also, pay attention to the shorting pins 4&5.  That may be why some users report 'slow charge'.    I'm going to make a cable both ways and see if that alters the charge rate.  (one with and one without pins 4&5 shorted together--just waiting on parts from china!)

Since these devices are so finniky w.r.t. voltage levels you need to also use fairly large power wires and keep them short... (see the cable that was supplied with the device... it wasn't short to save $$, it was short because it had to be!)

[Krollo]

Another stream 7 user here--Confirming that modifying a USB cable with breakaway female connector allows for charging and OTG.

[EDIT: OTG cables do not charge properly, however regular USB cables split to a USB female works fine]

Thank you for posting this as I never would have tried this (due to numerous claims that it isn't possible).

[Berza]

I made the same cable  but soldered a 100k resistor and connected a 5volts 2amp adapter. Works perfectly, but if you connect 3 usb devices or more charging stops ( battery doesn´t decrease).

Leo, thanks for posting. This motivates me to make my cable.

[david1024]

Not sure what the resistor does for these tablets. Probably doesn't hurt, just a pita to install. These devices key off the USB voltage (over 5.18v) to charge. So, any adapter that can supply the current and keep the voltage up will work. However, when he device is "off" it will charge off anything at whatever rate the supply can sustain.