Short Battery life

I just bought My Passport Pro 2T. After uploading around 2GB by USB cable, I noticed battery was almost fully discharged. After recharge I wanted to stream one movie (over 2 h), battery went down to 48%. Checking disk specification, it should stay 6-10h, depending on usage, so it should stay much longer than mine.
Is there anyway to make battery test? Can it be replaced under warranty?

Streaming is a high-usage case. I would not expect to get full quoted battery life if actively streaming content.

Thanks for reply.
So how I can check if battery is fine? What does it mean standard usage?
I left fully charged disk, connected to WiFi, and when I checked it after 7h, battery was down, but don’t know exactly when disk switched off.

Well. . . I would contact WD.

Simply being “on” is not a high usage case.

I can’t say how long I get. . . generally when I use it I plug it into power if I have it running for more than an hour.

I bought my HDD yesterday and the same thing happened with me. I charged it completely and around 50% it went to zero. It wouldn’t start once I shut it down after around 50%. Now I am trying to charge it 100% again and re-check.