You folks want to see battery drain, try the HDMI out. Jeepers. HDMI out works great, but even when using USB to help keep the device charging, it is a net negative- and then some. I do not even think the stock battery would last for a two hour movie, unless usb is plugged in. Zoinks!
That is if playing back local. If streaming with Netflix, cut it to about 90 minutes. Estimate, but not thinking too far off.