Pineapple + USB Battery + USB Tethering = FAIL?

[evilsocket]

Hi everyone, I'm the happy owner of a MKV which I use (when I take it out with me) with an Anker Astro E7 USB battery.

When I connect the MKV to my home power supply, I'm perfectly able to use my Galaxy S6 as a 4G modem ( using the USB port on the MKV and enabling USB tethering ), but when I'm not home and I try to use the same exact configuration with the battery, the phone simply doesn't detect the USB connection thus doesn't allow me to enable tethering ( basically it's just like the phone's connected to absolutely nothing ).

I guess this is due to some power requirements of the phone? Any chance to fix this? I vaguely remember I used tethering with my old phone ( a LG Nexus 5 ) and it worked, so the Galaxy S6 is probably draining more power than the battery is actually able to give?

Thanks.