HP Stream 7 Plugged In Not Charging

[rickyli99]

That blows, and thanks for talking to HP for us. That's a bullet not many are willing to take. TBH if it really is designed to be charge to 96% and stop, then it's kinda easy to (re)program the firmware to report anything above 90% as full charge. However I agree, not normal to stop at 50, 60 or any percentage below. 

[rickyli99]

I haven't been able to find a way to enable percentages/time remaining etc in control panel. However if you hover over the battery icon in the status bar it'll give you a percent.

[ProfileEngineer]

We did some testing here with a single  stream 7 we are evaluating and discovered that our unit requires a slightly higher charging voltage in order to charge at high current.  By using a variable supply the output voltage must be above about 5.15 volts for the steam 7 to charge properly.  Many of the off the self USB charging supplies, both mobile and AC units only output between 5.00-5.10V. 

[rickyli99]

Interesting, so it's not just an availble amps thing. Thanks for testing.

[ProfileEngineer]

Correct, you also need to make sure your cable isn't too long.  The longer the cable the more voltage drop you will have at a high charging current.  The longer the cable the larger diameter wire needs to be used in order to avoid the voltage drop. When the tablet first goes into it's charging mode it slowly increases the current and checks to make sure the voltage does not drop too much as the current increases.  Some inexpensive cables will have 28 awg wires for all the conductors, make sure you are using cables with 22 awg on the power conductors.  For example the cable that came with out Dell Venu  8 Pro is listed as 28 A AWG/1P + 22 AWG/2C, which indicates that the two data lines are 28 AWG and the power wires are a larger 22 AWG.  Unfortunely most of the charging units that are available do not have an easy way to bump up the voltage up slightly to 5.15V.

[sirfelix]

profilengineer,

Thanks for the testing.

A mobile device needs to do one of two things:

1. Run more than 3 hours unplugged, or

2. Be able to charge while running.

This HP tablet does neither.

I did a few experiments too and almost any charger/cable configuration other than the original ones horribly fails at charging this tablet.

I think its possible that we got a bad batch of AC adapters. The HP Stream Maintenance manual states we can use USB cables up to 6.5 feet to charge, but my tests show anything over 2 feet or any use of extension cables fail to provide the tablet with enough volts/amps a per profileengineer's tests.

So other than sitting on the floor next to the outlet, or charging while off, the charging annoyances on this device make for a very poor experience.

Lets hope HP can do something with the BIOS or Software to correct the problem.

[ProfileEngineer]

The problem is indeed with the tablet and not the charging supplies.  I'm guessing the problem is with the charging electronics and not anything they can fix in firmware.

It apears that they attempted to fix the problem by increasing the voltage on the wall charger slightly to make the charging system work.  Or perhaps they intentionally made the charging system only charge at the slightly higher voltage so that it would only charge with their wall adaptors and car adaptors.  

Increasing the charging voltage from 5V to above 5.15V -5.20V(depending on your cable length) will allow the tablet to charge at around 1.5A charging current. At less than about 5.05V the unit will only charge at .5A which isn't enough to keep up with current draw when the tablet is on.

[leo_kendall]

my hp stream 7 i had for a few weeks works fine with my acer iconic 7" tablet charger.  Works with my samsung galaxy tab 2 charger as well.  chargers up to 97 percent.

[leo_kendall]

any works with any generic usb cord

[r0ldy]

Well after a couple more days I started to notice my usb connection was getting loose. If i angle the plug upwards a little bit, the connection would register. I decided to stop messing around with this particular tablet and took it back to the Microsoft store where it was easily and quickly exchanged. The new tablet is much more consistent connection wise. I just need to get over the fact it'll never be 100% most of the time.

Before I went back to the MS store I called help again (it's still terrible). They can't repair the unit but they will send a certified/refurbished tablet for exchange. You'll also have to give them a credit card to place a hold on it - up until the exchange is completed. I figured I'd try the MS store before doing this and thankfully the store was super cool about this (I originally purchsed the tablet there).