My Passport Wireless shutting down

So I have a My Passport Wireless 2TB that I purchased to transfer photos from SD card without the need for a PC. The problem I’m having is if I log on to the drive then insert a SD card and initiate transfer to the drive it will start but usually less than a minute into the transfer the drive suddenly switches off. Sometimes I can press the power button and it boots back up and other times it’s completely dead and the only way to get it to boot back up is to plug it into power. Also if I go to Diagnostics and try to run Quick Test or Full Test, after about the same time as trying to transfer (about 25% of the way through the test) the drive switches off.
I have updated the firmware to v1.07.02
I have checked the drive for errors with my PC and it’s all clear.
When I boot the drive back up it has almost full battery.

Now here’s what I think is the weird part…
• If I set it to auto transfer from the SD card.
• I do not connect to the drive by WiFi from PC or mobile.
• I the plug it in to a wall charger.
If I then insert an SD card it will copy to the drive perfectly (even from a 64GB card almost full). This works every time.
I tried the same test without the charger and after a minute I got the red LED’s and the drive went into Recovery Mode and I had to set it up again…
So I can use it with this method but I’m concerned that it could fail further. I can take it back but they can’t give me a new one as they are now discontinued and it’ll cost me twice as much to get the new My Passport Wireless Pro.
Do you think it’s a hardware or a software issue?

I sounds like a power issue since things operate normally when running on the charger. I would check again with the retailer and see if they can have one sent to their store if it is a retail chain. You can try reloading the firmware manually while you have the drive running on the charger.The other option would be to call Western Digital and get it replaced under warranty. 1-800-275-4932.