HP Notebook Power Bank bug (and fix!)

There is a bug in the external HP battery, “HP Notebook Power Bank”, p/n N9F71AA#ABA.

There are two places this bug appears, and if one happens, the other also happens:

1.                   Plugged into your laptop, with one of these conditions:

•        The external battery will turn off after about 10 seconds, then flash all LEDs repeatedly.

•        The laptop will display a message saying that you need to use a full-power device to charge your laptop, and after about 10-20 seconds, the battery icon in your system tray will no longer show it is plugged in.

2.                   Plugged into a phone:

•        The external battery will charge with low power mode only.

If you have this bug, here is how to fix it:

1.                   Plug a power supply into the battery pack.

2.                   Plug laptop into the battery pack.

3.                   Unplug battery pack from the power supply.

4.                   Briefly press the battery pack button once.

5.                   If the LEDs flash again, repeat step 4.

At this point, the bug should be fixed.